Category: Battery Knowledge

Battery Knowledge

The OPzS2-1500 2V1500Ah is a 2 V, 1500 amp-hour flooded tubular vented lead-acid cell rated at the ten-hour rate — 150 A for 10 hours to 1.80 V per cell at 20 °C — and it is the right cell when a utility-scale solar or wind plant, a large telecom power room or a rail traction substation needs a 48 V or 96 V DC bus holding roughly 72 kWh or 144 kWh nominal per string, and when somebody on site will still top up water and read a hydrometer once a quarter.

It is not a sealed cabinet. It is a component of a room: hydrogen venting, flame-retardant acid-proof vent plugs, quarterly water top-up, periodic equalisation and a specific-gravity check are part of the product, not optional extras.

Five facts decide most projects:

  • 275 × 210 × 850 mm, 850 mm over terminals, 71.0 kg without electrolyte and 98 kg with it. A 24-cell 48 V string is 2,352 kg of battery on the floor before racks, busbar and the room.
  • Maximum charging current 300 A, 0.20 C10. That single limit caps what a solar array can push into the string at about 14.5 kW at 48 V nominal.
  • Float 2.23 V per cell at 25 °C with −3 mV/°C/cell compensation; equalise 2.35 V per cell at 25 °C. Charge controllers for renewable duty need the separate setpoints listed in §4, not the generic defaults.
  • Designed floating life 20+ years at 20 °C. The float life holds at 20 °C and falls away sharply above it — this is the most expensive lesson in this chemistry.
  • Internal resistance ≈0.40 mΩ fully charged at 20 °C; short-circuit current 5,400 A. A 24-cell string presents about 9.6 mΩ in series and delivers roughly 5,000 A on a hard short.

The OPzS2-1500 2V1500Ah sits between the OPzS2-1000 and the OPzS2-2000 in the same product range. That position is deliberate: it is the capacity step that matches the array sizes now being tendered for 48 V utility DC buses, and it absorbs 300 A per cell while still being handled by two people.

Key Takeaways

  • 1,500 Ah at C10, 150 A for 10 hours to 1.80 V per cell at 20 °C. The rating is a ten-hour rate, so size your string on C10, not on the higher one-hour or three-hour figures a distributor quotes.
  • 71.0 kg dry, 98 kg with electrolyte, 27 kg of acid. Handling is a two-person job with a trolley, and the floor loading must be checked before the plinth is poured.
  • Maximum charging current 300 A per cell (0.20 C10). A 48 V string accepts 7,200 A, which is about 14.5 kW at nominal bus voltage.
  • Float 2.23 V, equalise 2.35 V per cell, −3 mV/°C/cell compensation, 20+ years float life at 20 °C. Solar and wind duty needs a different setpoint table entirely — see §4.
  • Internal resistance ≈0.40 mΩ, short-circuit current 5,400 A, maximum discharge 2,500 A for 5 s. Protection coordination and cable sizing follow directly from these numbers.

§1 — OPzS2-1500 2V1500Ah Published Specifications

Every figure below comes from the CHISEN OPzS2-1500 factory datasheet. Where a value is a calculation rather than a printed figure, the source column says so. Values the datasheet does not print are written as “not published” rather than estimated, because an estimate on a procurement sheet becomes an engineering assumption nobody re-checks.

ParameterPublished valueSource
ModelOPzS2-1500Datasheet
Chemistry and constructionFlooded tubular vented lead-acid: die-cast Pb-Sb tubular positive plate, pasted lead-calcium negative plate, low-resistance PVC composite separator, transparent SAN container, high-strength ABS coverDatasheet
Nominal voltage2 V per cellDatasheet
Rated capacity (C10)1,500 Ah, 150 A for 10 h to 1.80 V per cell at 20 °CDatasheet
Cell dimensions275 × 210 × 850 mmDatasheet
Container (jar) height795 mmDatasheet
Total height over terminals850 mmDatasheet
Top view275 × 210 mmDatasheet
Terminal centre spacing108 mmDatasheet
Weight without electrolyte71.0 kg (157 lbs)Datasheet
Weight with electrolyte98 kg (216 lbs)Datasheet
Electrolyte (acid) weight27 kg at 1.240 g/cm³Datasheet
Internal resistance≈0.40 mΩ fully charged at 20 °CDatasheet
Short-circuit current5,400 ADatasheet
Maximum discharge current2,500 A for 5 sDatasheet
Maximum charging current300 ADatasheet
Charge characteristicConstant-current then constant-voltage, tapering to 0.15 CA below the float voltageDatasheet
Float charge voltage2.23 V per cell at 25 °C, −3 mV/°C/cell temperature compensationDatasheet
Equalise charge voltage2.35 V per cell at 25 °C, 20–25 °C rangeDatasheet
Self-discharge≈4 % per month at 20 °CDatasheet
Ambient temperature, discharge−25 °C to 65 °CDatasheet
Ambient temperature, charge−20 °C to 65 °CDatasheet
Ambient temperature, storage−15 °C to 40 °CDatasheet
Designed floating life20+ years at 20 °CDatasheet
Terminal typeFemale copper insert, M8 thread, 20 mm outer diameterDatasheet
Terminal tightening torque10–12 N·mDatasheet
Vent plugsAcid-proof, flame-retardant, explosion-proof; catalytic plug optionalDatasheet
Applicable standardsIEC 60896-11, DIN 40736, IEC 61427, Eurobat long-life guide, BS 6290 part 4, UL 1989Datasheet
CertificationsISO 9001, ISO 14001, OHSAS 18001:2007 (GB/T 28001), CEDatasheet

Solar and wind long-time discharge

For renewable duty the useful capacity is quoted at a lower cut-off voltage, because the controller protects the battery long before the cell reaches 1.80 V. The datasheet publishes the following capacities at a 1.85 V cut-off:

RateCapacity at 1.85 V per cellSource
C241,695 AhDatasheet
C481,860 AhDatasheet
C721,950 AhDatasheet
C1002,025 AhDatasheet
C1202,055 AhDatasheet
C2402,100 AhDatasheet

§2 — The Pain: Why Utility-Scale Purchases Go Wrong

First, the capacity number without a rate is not a number. The OPzS2-1500 2V1500Ah is rated at C10. A distributor who quotes “1,500 Ah” without the rate is quoting a figure that does not describe your duty. At a one-hour discharge the cell gives roughly half its C10 capacity; at a ten-hour discharge it gives the full figure. A utility plant that rides out a cloudy night on a slow discharge sits close to the C10 curve, while a ride-through cabinet with a five-minute discharge at high load sees far less. Specify the rate and the cut-off voltage together with the capacity, always.

Second, flooded means a room, not a container. Hydrogen evolves during charging and needs a path out. Acid-proof flame-retardant vent plugs handle the ignition source; they do not handle the accumulation. Every OPzS2-1500 installation needs mechanical ventilation sized for the worst-case float and equalisation charge, and it needs a person with a hydrometer and a top-up bottle on a schedule. Buyers who treat the OPzS2-1500 2V1500Ah as a drop-in replacement for a sealed block discover the difference in the first hot season.

Third, charge acceptance quietly caps the whole project. The published maximum charging current for the OPzS2-1500 is 300 A, which is 0.20 C10. At 48 V nominal that is about 14.5 kW. An array sized on the load rather than on the battery is an array the battery cannot absorb. The excess goes into float losses, extended equalisation, or an over-voltage disconnect that takes the inverter out of service. The array is the expensive half of a utility project, so fix this number before the panels are ordered.

Fourth, the float life is temperature-bound, and the datasheet is specific about it. The designed floating life of 20+ years is stated at 20 °C, and it is roughly halved for every 10 °C above that. A container in Chennai, Durban or Karachi that runs at 30 °C ambient all year is looking at a life closer to ten years, not twenty, and no controller precision changes that. Room cooling is a battery decision, not a comfort decision.

Fifth, the physical envelope is not negotiable. 275 mm long, 210 mm wide and 850 mm tall over terminals, with 98 kg filled. Rack pitch, aisle width, door clearance and the lifting route for a single cell all have to be confirmed against the drawing before the plinth is poured. Substituting a guess is how a delivery arrives that cannot be installed.

§3 — The Choice: Where the OPzS2-1500 Sits

The alternative to the OPzS2-1500 2V1500Ah is rarely another chemistry. In utility renewable, substation and large telecom markets where this cell is specified, the real choice is the same flooded platform at a different capacity, the gel variant of the same platform, or a sealed VRLA block of lower capacity.

Against the neighbouring flooded capacities

ParameterOPzS2-1000 2V1000AhOPzS2-1500 2V1500AhOPzS2-2000 2V2000Ah
Rated capacity (C10)1,000 Ah1,500 Ah2,000 Ah
Cell dimensions233 × 210 × 645 mm275 × 210 × 850 mm399 × 210 × 826 mm
Total height over terminals645 mm850 mm826 mm
Weight without electrolyte53.5 kg71.0 kg106 kg
Weight with electrolyte73.5 kg98 kg146 kg
Internal resistance0.45 mΩ at 20 °C0.40 mΩ at 20 °C0.35 mΩ at 20 °C
Maximum charging current200 A300 A400 A
Short-circuit current4,500 A5,400 A6,000 A
Float voltage2.23 V per cell2.23 V per cell2.23 V per cell
Designed float life20+ years at 20 °C20+ years at 20 °C20+ years at 20 °C

The middle column is the OPzS2-1500 datasheet; the OPzS2-1000 and OPzS2-2000 figures are the published values for those models. Three observations follow directly.

The OPzS2-1500 absorbs 300 A per cell, so a 48 V string of 24 cells accepts 7,200 A. That covers an array of roughly 14.5 kW on one string. Below that the OPzS2-1000 at 200 A is the natural choice; above it the OPzS2-2000 at 400 A is.

Internal resistance falls from 0.45 mΩ to 0.35 mΩ across this range, which makes a large string electrically cleaner at the same fault duty and why voltage recovery after a load step is less punishing on the bigger cells.

Height is not shared across the range: the OPzS2-1000 stands 645 mm over terminals while the OPzS2-1500 and OPzS2-2000 stand 850 mm and 826 mm. A rack built for one is not a rack for another, so the OPzS2-1500 drawing governs the aisle and the lifting route.

The 48 V string arithmetic

Every number below is derived from the published per-cell figures above.

Derived quantityCalculationResult
String nominal energy24 × 2 V × 1,500 Ah72 kWh
String series resistance24 × 0.40 mΩ9.60 mΩ
String maximum charging current24 × 300 A7,200 A
String maximum discharge current (5 s)24 × 2,500 A60,000 A
String weight filled24 × 98 kg2,352 kg
String weight dry24 × 71.0 kg1,704 kg
String acid weight24 × 27 kg648 kg
Short-circuit current at the terminals48 V ÷ 9.60 mΩ≈5,000 A

The last line is a calculation, not a datasheet figure: the published short-circuit current of 5,400 A is the manufacturer’s value for the cell and governs protection coordination. Use the published number for coordination and treat the derived figure as a sanity check on the wiring.

Flooded against gel

If nobody will ever touch the battery — no water top-up, no quarterly equalisation, no hydrometer — the gel version of this platform is the better product, and the OPzS2-1500 2V1500Ah is the wrong choice. Gel removes the room requirement: no ventilation path, no topping up, no hydrogen accumulation. The cost is a lower published cycle-life floor and marginally higher internal resistance. Make that trade explicitly, because it is a labour decision as much as a chemistry decision.

§4 — The Framework: Nine Things to Fix Before the Order

1. Lock the rate with the capacity. Write “OPzS2-1500 2V1500Ah, 1,500 Ah at C10 to 1.80 V per cell at 20 °C” on the purchase order, not “1,500 Ah”. If the duty is a shorter discharge, ask for the capacity at that rate and at the cut-off voltage the controller will use.

2. Fix the string architecture on paper first. 24 cells at 2 V gives 48 V nominal, which is the common utility and telecom DC bus. 48 cells gives 96 V. Write the cell count, the nominal bus voltage and the end-point voltage at 1.80 V per cell — 43.2 V for a 24-cell string — next to the load list. Every downstream number, from charger rating to cable cross-section, follows from those three figures.

3. Check the charge ceiling against the array. Maximum charging current is 300 A per cell, so 7,200 A for a 24-cell string, roughly 14.5 kW at 48 V nominal. If the array exceeds that, step up one capacity in the range or fit a charge-current limit in the controller. Decide before the array is ordered.

4. Use the renewable setpoint table, not the generic one. For solar and wind the datasheet publishes a dedicated set of controller parameters, and they are not the same as the stationary float-and-equalise pair:

ParameterValueSource
Over-voltage disconnect2.47 ± 0.01 V per cellDatasheet
Regulation / equalise voltage2.40 ± 0.01 V per cellDatasheet
Array reconnection voltage2.23 ± 0.005 V per cellDatasheet
Float voltage setting2.25 ± 0.005 V per cellDatasheet
Low-voltage alarm1.95 ± 0.005 V per cellDatasheet
Low-voltage disconnect1.90 ± 0.005 V per cellDatasheet
Load reconnect voltage2.09 ± 0.01 V per cellDatasheet
Temperature compensation coefficient−4 mV per cell per °CDatasheet

Note the deliberate difference from the stationary setpoints in §1. The renewable float setting is 2.25 V per cell, not 2.23 V, and the renewable compensation coefficient is −4 mV per cell per °C, not −3 mV. Renewable charging is intermittent, so the controller holds the array at a slightly higher potential to capture what light there is, and the −4 mV coefficient is matched to the wider temperature swing of an outdoor cabinet. Copying the stationary numbers into a solar controller is a common and expensive error.

5. Design the ventilation path. Hydrogen evolves on charge. Provide mechanical extraction sized for the worst-case charge case, keep flame-retardant acid-proof vent plugs fitted, and confirm the room is not a sealed container with one door.

6. Schedule the water. An OPzS2-1500 cell loses water on every charge cycle. Quarterly top-up with distilled or demineralised water, a quarterly specific-gravity reading on every cell and a logged equalisation at a defined interval are operating requirements, not maintenance extras. Budget the labour; a battery that is never checked fails at the worst time.

7. Confirm the mechanical envelope against the drawing. For the OPzS2-1500: 275 × 210 × 850 mm, 98 kg filled, terminal centre spacing 108 mm, M8 female insert at 10–12 N·m. Rack pitch, door clearances, the lifting route for a 98 kg cell and the floor loading all need the drawing, not a spreadsheet.

8. Set the end-of-life criterion now. Define the capacity floor — the percentage of rated C10 at which the string is replaced — and put it in the maintenance plan with a date attached. Without a written criterion, end-of-life is a judgement call made under pressure during an outage.

9. Order the spares policy deliberately. Cells in a series string age unevenly. Decide in advance whether you hold one spare OPzS2-1500 cell on site, and note that a spare must be the same model and age band as the string, not a newer cell dropped into an older string.

§5 — The Trust: Who Built It and What Is Certified

CHISEN operates 8 production bases with an annual capacity of 70 million kVAh, which is the scale behind the published datasheet rather than a marketing figure on a web page. The OPzS2-1500 2V1500Ah is built to IEC 60896-11 for stationary lead-acid valves and DIN 40736 for tubular cells, with IEC 61427 and BS 6290 part 4 also applicable and the UL 1989 listing covering the North American side. The Eurobat long-life guide applies to the float-life claim. The manufacturing system is certified to ISO 9001 for quality management and ISO 14001 for environmental management, with OHSAS 18001:2007 (GB/T 28001) covering occupational health and safety, and the product carries CE marking. Every export shipment is documented with CE, UL and IEC certification papers for the exact variant.

Those standards matter commercially, not just decoratively. DIN 40736 and IEC 60896-11 are what an importer’s technical file has to cite for EU market access; BS 6290 part 4 and UL 1989 are what a buyer in Mumbai, Karachi, Durban or a Gulf port asks for when the battery is going into a tender. The same document set is requested in Rotterdam, Hamburg, Jebel Ali, Santos, Mombasa, Antwerp, Colombo and Lagos: the standards are identical, the local authority requirements are not.

The certification set is a claim you can verify rather than take on trust: request the test certificates for the exact model, check that the scope covers the 1,500 Ah variant, and confirm the certificate address matches the supplier quoting it. Do this before a 24-cell OPzS2-1500 string lands on your floor, because a certificate that does not cover the variant is a documentation problem discovered at the wrong moment.

The 8 production bases and 70 million kVAh of capacity also matter for delivery risk on a large project. A 48 V string of 24 OPzS2-1500 cells at 98 kg filled is 2,352 kg of battery from one production base, and a mixed-date delivery is a mixed-age string. Ask for the manufacturing date on the cells, and ask that the whole string be produced within one production window.

§6 — FAQ: OPzS2-1500 2V1500Ah

Q1. What is the rated capacity of the OPzS2-1500 2V1500Ah? 1,500 Ah at the ten-hour rate, meaning 150 A for 10 hours to a 1.80 V per cell cut-off at 20 °C. The datasheet also publishes renewable long-time discharge capacities at a 1.85 V cut-off, from 1,695 Ah at C24 up to 2,100 Ah at C240.

Q2. What are the physical dimensions and weight of one OPzS2-1500 cell? 275 × 210 × 850 mm overall, with a 795 mm container and 850 mm height over terminals. 71.0 kg without electrolyte, 98 kg with electrolyte, and 27 kg of acid at 1.240 g/cm³. One filled cell is a two-person handling job.

Q3. What float and equalise voltages should the charger use? Float 2.23 V per cell at 25 °C with −3 mV/°C/cell compensation, and equalise 2.35 V per cell at 25 °C over a 20–25 °C range. For solar and wind duty the controller setpoints differ — 2.25 V float and a −4 mV per cell per °C coefficient — and are listed in §4.

Q4. How much current can the OPzS2-1500 take during charging? The published maximum charging current is 300 A, which is 0.20 C10. A 24-cell 48 V string therefore accepts 7,200 A, roughly 14.5 kW at nominal bus voltage. Exceeding that limit pushes the array into float losses or triggers an over-voltage disconnect.

Q5. What are the internal resistance and short-circuit current of the OPzS2-1500? Internal resistance is approximately 0.40 mΩ fully charged at 20 °C. The published short-circuit current is 5,400 A, and the maximum discharge current is 2,500 A for 5 s. A 24-cell string presents 9.60 mΩ in series.

Q6. How long does the OPzS2-1500 2V1500Ah last in float service? The designed floating life is 20+ years at 20 °C. Float life falls by roughly half for every 10 °C above 20 °C, so an uncooled container at 30 °C ambient should expect materially less.

Q7. What maintenance does the OPzS2-1500 require? Quarterly water top-up with distilled or demineralised water, a quarterly specific-gravity reading on every cell, equalisation on a logged schedule, and hydrogen ventilation sized for the worst-case charge case. Acid-proof flame-retardant vent plugs must stay fitted.

Q8. Can the OPzS2-1500 2V1500Ah be used for solar storage? Yes, and the datasheet publishes a dedicated setpoint table for renewable duty, including the 2.47 ± 0.01 V over-voltage disconnect, the 2.40 ± 0.01 V regulation voltage and the 1.90 ± 0.005 V low-voltage disconnect. The 300 A maximum charging current still applies, so the array must be sized against it.

Q9. What certifications does the OPzS2-1500 2V1500Ah carry? Built to IEC 60896-11, DIN 40736, IEC 61427, the Eurobat long-life guide, BS 6290 part 4 and UL 1989. The manufacturing system is certified to ISO 9001 and ISO 14001, with OHSAS 18001:2007 (GB/T 28001), and the product carries CE marking.

Expert Summary

The OPzS2-1500 2V1500Ah is a 2 V, 1,500 Ah flooded tubular cell for 48 V and 96 V DC strings in utility renewable plants, large telecom power rooms and traction substations. Its published envelope is 275 × 210 × 850 mm at 71.0 kg dry and 98 kg filled, with 0.40 mΩ internal resistance, a 5,400 A short-circuit current and a 300 A maximum charging current.

Four decisions carry the project. Size on C10 with the cut-off voltage attached to the capacity. Respect the 300 A charge ceiling when the array is specified, or step up one capacity in the range. Use the renewable setpoint table for solar and wind rather than the stationary pair. And budget the labour and ventilation a flooded cell needs, because the 20+ year float life at 20 °C only holds in a maintained, ventilated, temperature-controlled room.

For a 24-cell 48 V string the arithmetic is 72 kWh nominal, 9.60 mΩ in series, 7,200 A of charge acceptance, 2,352 kg of installed battery and 648 kg of acid. Take those five numbers to the civil and electrical design, and the OPzS2-1500 2V1500Ah will do what the datasheet says it does.

Contact CHISEN

Technical enquiries, project drawings and tender documents: sales@chisen.cn and +86 131 6622 6999 on WhatsApp. Mention the model OPzS2-1500 and the string voltage you are designing for, and the CHISEN team will supply the certified per-cell datasheet, the certified weight, the drawing and the test certificates for the exact variant.

Related reading: the OPzS2-1500 2V1500Ah model page, the OPzS2-2000 2V2000Ah model page for the cell above it in the range, and the OPzS flooded tubular battery range for the full platform.

Related CHISEN Buyer Guides

  • OPzS2-800 2V800Ah Flooded Tubular Battery: Specs, String Sizing and Telecom DC Plant Use

    OPzS2-800 2V800Ah Flooded Tubular Battery: Specs, String Sizing and Telecom DC Plant Use

    Answer First

    The OPzS2-800 2V800Ah is a 2 V, 800 amp-hour flooded tubular vented lead-acid cell rated at the 10-hour rate — 80 A for 10 hours to 1.80 V per cell at 20 °C — and it is the right cell when a telecom DC plant, a substation or a solar-plus-storage cabinet needs a 48 V or 96 V bus holding roughly 19 kWh or 38 kWh nominal per string, and when somebody on site will still top up water and read a hydrometer once a quarter.

    It is not a sealed cabinet. It is a component of a room: hydrogen venting, flame-retardant acid-proof vent plugs, quarterly water top-up, quarterly equalisation and a specific-gravity check are part of the product, not optional extras.

    Five facts decide most projects:

    • 191 × 210 × 700 mm, 700 mm over terminals, 42.0 kg without electrolyte and 58 kg with it. A 24-cell 48 V string is 1,392 kg of battery on the floor before racks, busbar and the room.
    • Maximum charging current 160 A, 0.20 C10. That single limit caps what a solar array can push into the string at about 7.7 kW at 48 V nominal.
    • Float 2.23 V per cell at 25 °C with −3 mV/°C/cell compensation; equalise 2.35 V per cell at 25 °C. Charge controllers for solar duty need the separate setpoints listed in §4, not the generic defaults.
    • Designed floating life 20+ years at 20 °C. The float life holds at 20 °C, and it falls away sharply above it — this is the single most expensive lesson in this chemistry.
    • Internal resistance ≈0.49 mΩ fully charged at 20 °C; short-circuit current 4,000 A. A 24-cell string presents about 11.8 mΩ in series and delivers roughly 4,075 A on a hard short.

    The OPzS2-800 2V800Ah sits between the OPzS2-600 and the OPzS2-1000 in the same product range. That position is deliberate: it is the smallest capacity in the range that still absorbs 160 A per cell, which is what a 48 V solar string with any meaningful array needs.

    Key Takeaways

    • 800 Ah at C10, 80 A for 10 hours to 1.80 V per cell at 20 °C. The rating is a 10-hour rate, so size your string on C10, not on the higher 1-hour or 3-hour figures a distributor quotes.
    • 42.0 kg dry, 58 kg with electrolyte, 16 kg of acid. Handling is a two-person job with a trolley, and the floor loading must be checked before the plinth is poured.
    • Maximum charging current 160 A per cell (0.20 C10). A 48 V string accepts 3,840 A, which is about 7.7 kW at nominal bus voltage.
    • Float 2.23 V, equalise 2.35 V per cell, −3 mV/°C/cell compensation, 20+ years float life at 20 °C. Solar and wind duty needs a different setpoint table entirely — see §4.
    • Internal resistance ≈0.49 mΩ, short-circuit current 4,000 A, maximum discharge 2,500 A for 5 s. Protection coordination and cable sizing follow directly from these two numbers.

    §1 — OPzS2-800 2V800Ah Published Specifications

    Every figure below comes from the CHISEN OPzS2-800 factory datasheet. Where a value is a calculation rather than a printed figure, the source column says so. Values the datasheet does not print are written as “not published” rather than estimated, because an estimate on a procurement sheet becomes an engineering assumption nobody re-checks.

    ParameterPublished valueSource
    ModelOPzS2-800Datasheet
    Chemistry and constructionFlooded tubular vented lead-acid: die-cast Pb-Sb tubular positive plate, pasted lead-calcium negative plate, low-resistance PVC composite separator, transparent SAN container, high-strength ABS coverDatasheet
    Nominal voltage2 V per cellDatasheet
    Rated capacity (C10)800 Ah, 80 A for 10 h to 1.80 V per cell at 20 °CDatasheet
    Cell dimensions191 × 210 × 700 mmDatasheet
    Container (jar) height645 mmDatasheet
    Total height over terminals700 mmDatasheet
    Top view210 × 191 mmDatasheet
    Terminal centre spacing108 mm × 110 mmDatasheet
    Weight without electrolyte42.0 kg (92.6 lbs)Datasheet
    Weight with electrolyte58 kg (128 lbs)Datasheet
    Electrolyte (acid) weight16 kg at 1.240 g/cm³Datasheet
    Internal resistance≈0.49 mΩ fully charged at 20 °CDatasheet
    Short-circuit current4,000 ADatasheet
    Maximum discharge current2,500 A for 5 sDatasheet
    Maximum charging current160 ADatasheet
    Charge characteristicConstant-current then constant-voltage, tapering to 0.15 CA below the float voltageDatasheet
    Float charge voltage2.23 V per cell at 25 °C, −3 mV/°C/cell temperature compensationDatasheet
    Equalise charge voltage2.35 V per cell at 25 °C, −5 mV/°C/cell temperature compensation, 20–25 °C rangeDatasheet
    Self-discharge≈4 % per month at 20 °CDatasheet
    Ambient temperature, discharge−25 °C to 65 °CDatasheet
    Ambient temperature, charge−20 °C to 65 °CDatasheet
    Ambient temperature, storage−15 °C to 40 °CDatasheet
    Designed floating life20+ years at 20 °CDatasheet
    Terminal typeFemale copper insert, M8 thread, 20 mm outer diameter, 7 mm thread depthDatasheet
    Terminal tightening torque10–12 N·mDatasheet
    Vent plugsAcid-proof, flame-retardant, explosion-proof; catalytic plug optionalDatasheet
    Applicable standardsIEC 60896-11, DIN 40736, IEC 61427, Eurobat long-life guide, BS 6290 part 4, UL 1989Datasheet
    CertificationsISO 9001, ISO 14001, OHSAS 18001:2007 (GB/T 28001), CE, RUDatasheet

    Solar and wind long-time discharge

    For renewable duty the useful capacity is quoted at a lower cut-off voltage, because the controller protects the battery long before the cell reaches 1.80 V. The datasheet publishes the following capacities at a 1.85 V cut-off:

    RateCapacity at 1.85 V per cellSource
    C24904 AhDatasheet
    C48992 AhDatasheet
    C721,040 AhDatasheet
    C1001,080 AhDatasheet
    C1201,096 AhDatasheet
    C2401,120 AhDatasheet

    §2 — The Pain: Why This Purchase Goes Wrong

    First, the capacity number is a trap. An OPzS2-800 2V800Ah cell is rated at C10. A distributor who quotes “800 Ah” without the rate is quoting a number that does not describe your duty. At a one-hour discharge the cell delivers roughly half its C10 capacity; at a ten-hour discharge it delivers the full figure. A cabinet that must carry a five-minute ride-through at high load sees far less. Specify the rate and the cut-off voltage with the capacity, always together.

    Second, flooded means a room, not a cabinet. Hydrogen evolves from the negative plates during charging, and it needs a path out. Acid-proof flame-retardant vent plugs handle the ignition source; they do not handle the accumulation. Every OPzS2-800 2V800Ah installation needs mechanical ventilation sized for the worst-case float and equalisation charge, plus a person with a hydrometer and a top-up bottle on a schedule. Buyers who treat the flooded cell as a drop-in replacement for a sealed block discover the difference in month three, usually during the first hot season.

    Third, charge acceptance quietly caps the whole project. The published maximum charging current for the OPzS2-800 2V800Ah is 160 A, which is 0.20 C10. At 48 V nominal that is about 7.7 kW. An array sized on the load rather than on the battery is an array the battery cannot absorb. The excess goes into float losses, extended equalisation, or an over-voltage disconnect that trips the inverter out of service.

    Fourth, the float life is temperature-bound, and the datasheet is specific about it. The designed floating life of 20+ years is stated at 20 °C, and it is roughly halved for every 10 °C above that. A power room in Chennai, Durban or Karachi that runs at 30 °C ambient all year is looking at a life closer to ten years, not twenty, and no controller precision changes that. Room cooling is a battery decision, not a comfort decision.

    Fifth, the physical envelope is not negotiable. 191 mm long, 210 mm wide and 700 mm tall over terminals, with 58 kg in the cell once filled. Rack pitch, aisle width, door clearance and the lifting route for a single cell all have to be confirmed against the drawing before the plinth is poured. Substituting a guess is how a delivery arrives that cannot be installed.

    §3 — The Choice: Where the OPzS2-800 Sits

    The alternative to the OPzS2-800 2V800Ah is rarely another chemistry. In the telecom, substation and containerised-renewable markets where this cell is specified, the real choice is the same flooded platform at a different capacity, the gel variant of the same platform, or a sealed VRLA block of a lower capacity.

    Against the neighbouring flooded capacities

    ParameterOPzS2-600 2V600AhOPzS2-800 2V800AhOPzS2-1000 2V1000Ah
    Rated capacity (C10)600 Ah800 Ah1,000 Ah
    Cell dimensions145 × 206 × 645 mm191 × 210 × 700 mm233 × 210 × 645 mm
    Total height over terminals700 mm700 mm700 mm
    Weight without electrolyte32.0 kg42.0 kg53.5 kg
    Weight with electrolyte42.8 kg58 kg73.5 kg
    Internal resistance0.60 mΩ at 20 °C0.49 mΩ at 20 °C0.45 mΩ at 20 °C
    Maximum charging current120 A160 A200 A
    Short-circuit current3,700 A4,000 A4,500 A
    Float voltage2.23 V per cell2.23 V per cell2.23 V per cell
    Designed float life20+ years at 20 °C20+ years at 20 °C20+ years at 20 °C

    All three figures in the middle column are from the OPzS2-800 datasheet; the OPzS2-600 and OPzS2-1000 figures are the published values for those models. Three observations follow directly.

    The OPzS2-800 is the smallest cell in this comparison that still absorbs 160 A per cell. If the array is larger than roughly 7.7 kW on a 48 V bus, the OPzS2-600 at 120 A becomes the limiting element and the OPzS2-1000 at 200 A is the natural step up.

    All three cells share the same 700 mm height over terminals, so a power room designed for one of them can be re-stuffed with another without rebuilding the rack geometry. The footprints differ, however: 145 × 206 mm, 191 × 210 mm and 233 × 210 mm are three different plans, so rack pitch and aisle width still need checking per model.

    Internal resistance falls as capacity rises, from 0.60 mΩ to 0.45 mΩ across the range, and that is what makes a large string electrically cleaner at the same fault duty.

    The 48 V string arithmetic

    Every number below is derived from the published per-cell figures above.

    Derived quantityCalculationResult
    String nominal energy24 × 2 V × 800 Ah38.4 kWh
    String series resistance24 × 0.49 mΩ11.76 mΩ
    String maximum charging current24 × 160 A3,840 A
    String maximum discharge current (5 s)24 × 2,500 A60,000 A
    String weight filled24 × 58 kg1,392 kg
    String weight dry24 × 42.0 kg1,008 kg
    String acid weight24 × 16 kg384 kg
    Short-circuit current at the terminals48 V ÷ 11.76 mΩ≈4,082 A

    The last line is a calculation, not a datasheet figure: the published short-circuit current of 4,000 A governs protection coordination. Use the published number for coordination and treat the derived figure as a sanity check on the wiring.

    Flooded against gel

    If nobody will ever touch the battery — no water top-up, no quarterly equalisation, no hydrometer — the gel version of this platform is the better product, and the OPzS2-800 2V800Ah is the wrong choice. Gel removes the room requirement: no ventilation path, no topping up, no hydrogen accumulation. The cost is a lower published cycle-life floor and marginally higher internal resistance. Make that trade explicitly, because it is a labour decision as much as a chemistry decision.

    §4 — The Framework: Nine Things to Fix Before the Order

    1. Lock the rate with the capacity. Write “OPzS2-800 2V800Ah, 800 Ah at C10 to 1.80 V per cell at 20 °C” on the purchase order, not “800 Ah”. If the duty is a shorter discharge, ask for the capacity at that rate and at the cut-off voltage the controller will use.

    2. Fix the string architecture on paper first. 24 cells at 2 V gives 48 V nominal, which is the common telecom DC bus. 48 cells gives 96 V. Write the cell count, the nominal bus voltage and the end-point voltage at 1.80 V per cell — 43.2 V for a 24-cell string — next to the load list. Every downstream number, from charger rating to cable cross-section, follows from those three figures.

    3. Check the charge ceiling against the array. Maximum charging current is 160 A per cell, so 3,840 A for a 24-cell string, roughly 7.7 kW at 48 V nominal. If the array exceeds that, step up one capacity in the range or fit a charge-current limit in the controller. Decide before the array is ordered.

    4. Use the renewable setpoint table, not the generic one. For solar and wind the datasheet publishes a dedicated set of controller parameters, and they are not the same as the stationary float-and-equalise pair:

    ParameterValueSource
    Over-voltage disconnect2.47 ± 0.01 V per cellDatasheet
    Regulation / equalise voltage2.40 ± 0.01 V per cellDatasheet
    Array reconnection voltage2.23 ± 0.005 V per cellDatasheet
    Float voltage setting2.25 ± 0.005 V per cellDatasheet
    Low-voltage alarm1.95 ± 0.005 V per cellDatasheet
    Low-voltage disconnect1.90 ± 0.005 V per cellDatasheet
    Load reconnect voltage2.09 ± 0.01 V per cellDatasheet
    Temperature compensation coefficient−4 mV per cell per °CDatasheet

    Note the deliberate difference from the stationary setpoints in §1. The renewable float setting is 2.25 V per cell, not 2.23 V, and the renewable compensation coefficient is −4 mV per cell per °C, not −3 mV. The reasons are practical: renewable charging is intermittent, so the controller holds the array at a slightly higher potential to capture what light there is, and the −4 mV coefficient is matched to the wider temperature swing of an outdoor cabinet. Copying the stationary numbers into a solar controller is a common and expensive error.

    5. Design the ventilation path. Hydrogen evolves on charge. Provide mechanical extraction sized for the worst-case charge case, keep flame-retardant acid-proof vent plugs fitted, and confirm the room is not a sealed container with one door.

    6. Schedule the water. An OPzS2-800 cell loses water on every charge cycle. Quarterly top-up with distilled or demineralised water, a quarterly specific-gravity reading on every cell and a logged equalisation at a defined interval are operating requirements, not maintenance extras. Budget the labour; a battery that is never checked fails at the worst time.

    7. Confirm the mechanical envelope against the drawing. For the OPzS2-800: 191 × 210 × 700 mm, 58 kg filled, terminal centre spacing 108 × 110 mm, M8 female insert at 10–12 N·m. Rack pitch, door clearances, the lifting route for a 58 kg cell and the floor loading all need the drawing, not a spreadsheet.

    8. Set the end-of-life criterion now. Define the capacity floor — the percentage of rated C10 at which the string is replaced — and put it in the maintenance plan with a date attached. Without a written criterion, end-of-life is a judgement call made under pressure during an outage.

    9. Order the spares policy deliberately. Cells in a series string age unevenly. Decide in advance whether you hold one spare OPzS2-800 cell on site, and note that a spare must be the same model and age band as the string, not a newer cell dropped into an older string.

    §5 — The Trust: Who Built It and What Is Certified

    CHISEN operates 8 production bases with an annual capacity of 70 million kVAh, which is the scale behind the published datasheet rather than a marketing figure on a web page. The OPzS2-800 2V800Ah is built to IEC 60896-11 for stationary lead-acid valves and DIN 40736 for tubular cells, with IEC 61427 and BS 6290 part 4 also applicable and the UL 1989 listing covering the North American side. The Eurobat long-life guide applies to the float-life claim. The manufacturing system is certified to ISO 9001 for quality management and ISO 14001 for environmental management, with OHSAS 18001:2007 (GB/T 28001) covering occupational health and safety, and the product carries CE marking. Every export shipment is documented with CE, UL and IEC certification papers for the exact variant.

    Those standards matter commercially, not just decoratively. DIN 40736 and IEC 60896-11 are what an importer’s technical file has to cite for EU market access; BS 6290 part 4 and UL 1989 are what a buyer in Mumbai, Karachi, Durban or a Gulf port asks for when the battery is going into a tender. The same document set is requested in Rotterdam, Hamburg, Jebel Ali, Santos, Mombasa, Antwerp, Colombo and Lagos: the standards are identical, the local authority requirements are not. The RU marking on this model is the recognised component listing for North American installations.

    The certification set is a claim you can verify rather than take on trust: request the test certificates for the exact model, check that the scope covers the 800 Ah variant, and confirm the certificate address matches the supplier quoting it. This is worth doing before a 24-cell OPzS2-800 string lands on your floor, because a certificate that does not cover the variant is a documentation problem discovered at the wrong moment.

    The 8 production bases and 70 million kVAh of capacity also matter for delivery risk. A 48 V string of 24 OPzS2-800 cells at 58 kg filled is 1,392 kg of battery from one production base, and a mixed-date delivery is a mixed-age string. Ask for the manufacturing date on the cells, and ask that the whole string be produced within one production window.

    §6 — FAQ: OPzS2-800 2V800Ah

    Q1. What is the rated capacity of the OPzS2-800 2V800Ah? 800 Ah at the 10-hour rate, meaning 80 A for 10 hours to a 1.80 V per cell cut-off at 20 °C. The datasheet also publishes renewable long-time discharge capacities at a 1.85 V cut-off, from 904 Ah at C24 up to 1,120 Ah at C240.

    Q2. What are the physical dimensions and weight of one cell? 191 × 210 × 700 mm overall, with a 645 mm container and 700 mm height over terminals. 42.0 kg without electrolyte, 58 kg with electrolyte, and 16 kg of acid at 1.240 g/cm³. One filled cell is a two-person handling job.

    Q3. What float and equalise voltages should the charger use? Float 2.23 V per cell at 25 °C with −3 mV/°C/cell compensation, and equalise 2.35 V per cell at 25 °C with −5 mV/°C/cell compensation over a 20–25 °C range. For solar and wind duty the controller setpoints differ — 2.25 V float and a −4 mV per cell per °C coefficient — and are listed in §4.

    Q4. How much current can this cell take during charging? The published maximum charging current is 160 A, which is 0.20 C10. A 24-cell 48 V string therefore accepts 3,840 A, roughly 7.7 kW at nominal bus voltage. Exceeding that limit pushes the array into float losses or triggers an over-voltage disconnect.

    Q5. What are the internal resistance and short-circuit current of the OPzS2-800? Internal resistance is approximately 0.49 mΩ fully charged at 20 °C. The published short-circuit current is 4,000 A, and the maximum discharge current is 2,500 A for 5 s. A 24-cell string presents 11.76 mΩ in series.

    Q6. How long does the OPzS2-800 2V800Ah last in float service? The designed floating life is 20+ years at 20 °C. Float life falls by roughly half for every 10 °C above 20 °C, so an uncooled power room at 30 °C ambient should expect materially less. Keep the room cool and the life figure holds.

    Q7. What maintenance does the OPzS2-800 require? Quarterly water top-up with distilled or demineralised water, a quarterly specific-gravity reading on every cell, equalisation on a logged schedule, and hydrogen ventilation sized for the worst-case charge case. Acid-proof flame-retardant vent plugs must stay fitted.

    Q8. Can this cell be used for solar storage? Yes, and the datasheet publishes a dedicated setpoint table for renewable duty, including the 2.47 ± 0.01 V over-voltage disconnect, the 2.40 ± 0.01 V regulation voltage and the 1.90 ± 0.005 V low-voltage disconnect. The 160 A maximum charging current still applies, so the array must be sized against it.

    Q9. What certifications does the OPzS2-800 2V800Ah carry? Built to IEC 60896-11, DIN 40736, IEC 61427, the Eurobat long-life guide, BS 6290 part 4 and UL 1989. The manufacturing system is certified to ISO 9001 and ISO 14001, with OHSAS 18001:2007 (GB/T 28001), and the product carries CE marking and RU listing.

    Expert Summary

    The OPzS2-800 2V800Ah is a 2 V, 800 Ah flooded tubular cell for 48 V and 96 V DC strings in telecom power rooms, substations and renewable cabinets. Its published envelope is 191 × 210 × 700 mm at 42.0 kg dry and 58 kg filled, with 0.49 mΩ internal resistance, 4,000 A short-circuit current and 160 A maximum charging current.

    Four decisions carry the project. Size on C10 with the cut-off voltage attached to the capacity. Respect the 160 A charge ceiling when the array is specified, or step up one capacity in the range. Use the renewable setpoint table for solar and wind rather than the stationary pair. And budget the labour and ventilation a flooded cell needs, because the 20+ year float life at 20 °C only holds in a maintained, ventilated, temperature-controlled room.

    For a 24-cell 48 V string the arithmetic is 38.4 kWh nominal, 11.76 mΩ in series, 3,840 A of charge acceptance, 1,392 kg of installed battery and 384 kg of acid. Take those five numbers to the civil and electrical design, and the OPzS2-800 2V800Ah will do what the datasheet says it does.

    Contact CHISEN

    Technical enquiries, project drawings and tender documents: sales@chisen.cn and +86 131 6622 6999 on WhatsApp. Mention the model OPzS2-800 and the string voltage you are designing for, and the CHISEN team will supply the certified per-cell datasheet, the certified weight, the drawing and the test certificates for the exact variant.

    Related reading: the OPzS2-800 2V800Ah model page, the OPzS2-600 2V600Ah model page for the cell below it in the range, and the OPzS flooded tubular battery range for the full platform.

    Related CHISEN Buyer Guides

  • OPzS2-2000 2V2000Ah Flooded Tubular Battery: Utility DC Plant and Grid-Scale Storage

    OPzS2-2000 2V2000Ah Flooded Tubular Battery: Utility DC Plant and Grid-Scale Storage

    Answer First

    The OPzS2-2000 2V2000Ah is a 2 V, 2000 amp-hour flooded tubular vented lead-acid cell rated at the ten-hour rate — 200 A for 10 hours to 1.80 V per cell at 20 °C — and it is the right cell when a utility DC plant, a grid-scale solar or wind installation or a major rail substation needs a 48 V or 96 V DC bus holding roughly 96 kWh or 192 kWh nominal per string, and when somebody on site will still top up water and read a hydrometer once a quarter.

    It is not a sealed cabinet. It is a component of a room: hydrogen venting, flame-retardant acid-proof vent plugs, quarterly water top-up, periodic equalisation and a specific-gravity check are part of the product, not optional extras.

    Five facts decide most projects:

    • 399 × 210 × 826 mm, 826 mm over terminals, 106 kg without electrolyte and 146 kg with it. A 24-cell 48 V string is 3,504 kg of battery on the floor before racks, busbar and the room.
    • Maximum charging current 400 A, 0.20 C10. That single limit caps what a solar array can push into the string at about 19.2 kW at 48 V nominal.
    • Float 2.23 V per cell at 25 °C with −3 mV/°C/cell compensation; equalise 2.35 V per cell at 25 °C. Charge controllers for renewable duty need the separate setpoints listed in §4, not the generic defaults.
    • Designed floating life 20+ years at 20 °C. The float life holds at 20 °C and falls away sharply above it — this is the most expensive lesson in this chemistry.
    • Internal resistance ≈0.35 mΩ fully charged at 20 °C; short-circuit current 6,000 A. A 24-cell string presents about 8.4 mΩ in series and delivers roughly 5,700 A on a hard short.

    The OPzS2-2000 2V2000Ah is the capacity step that lets a utility project build one string instead of two. At this size the string count, not the cell count, is what moves the civil works: fewer strings means fewer racks, fewer cabinets and fewer parallel DC distribution boards to design, specify and maintain.

    Key Takeaways

    • 2,000 Ah at C10, 200 A for 10 hours to 1.80 V per cell at 20 °C. The rating is a ten-hour rate, so size your string on C10, not on the higher one-hour or three-hour figures a distributor quotes.
    • 106 kg dry, 146 kg with electrolyte, 40 kg of acid. Handling is a two-person job with a trolley, and the floor loading must be checked before the plinth is poured.
    • Maximum charging current 400 A per cell (0.20 C10). A 48 V string accepts 9,600 A, which is about 19.2 kW at nominal bus voltage.
    • Float 2.23 V, equalise 2.35 V per cell, −3 mV/°C/cell compensation, 20+ years float life at 20 °C. Solar and wind duty needs a different setpoint table entirely — see §4.
    • Internal resistance ≈0.35 mΩ, short-circuit current 6,000 A, maximum discharge 3,600 A for 5 s. Protection coordination and cable sizing follow directly from these numbers.

    §1 — OPzS2-2000 2V2000Ah Published Specifications

    Every figure below comes from the CHISEN OPzS2-2000 factory datasheet. Where a value is a calculation rather than a printed figure, the source column says so. Values the datasheet does not print are written as “not published” rather than estimated, because an estimate on a procurement sheet becomes an engineering assumption nobody re-checks.

    ParameterPublished valueSource
    ModelOPzS2-2000Datasheet
    Chemistry and constructionFlooded tubular vented lead-acid: die-cast Pb-Sb tubular positive plate, pasted lead-calcium negative plate, low-resistance PVC composite separator, transparent SAN container, high-strength ABS coverDatasheet
    Nominal voltage2 V per cellDatasheet
    Rated capacity (C10)2,000 Ah, 200 A for 10 h to 1.80 V per cell at 20 °CDatasheet
    Cell dimensions399 × 210 × 826 mmDatasheet
    Container (jar) height772 mmDatasheet
    Total height over terminals826 mmDatasheet
    Top view210 × 399 mmDatasheet
    Terminal centre spacing110 mm × 110 mmDatasheet
    Weight without electrolyte106 kg (234 lbs)Datasheet
    Weight with electrolyte146 kg (322 lbs)Datasheet
    Electrolyte (acid) weight40 kg at 1.240 g/cm³Datasheet
    Internal resistance≈0.35 mΩ fully charged at 20 °CDatasheet
    Short-circuit current6,000 ADatasheet
    Maximum discharge current3,600 A for 5 sDatasheet
    Maximum charging current400 ADatasheet
    Charge characteristicConstant-current then constant-voltage, tapering to 0.15 CA below the float voltageDatasheet
    Float charge voltage2.23 V per cell at 25 °C, −3 mV/°C/cell temperature compensationDatasheet
    Equalise charge voltage2.35 V per cell at 25 °C, 20–25 °C rangeDatasheet
    Self-discharge≈4 % per month at 20 °CDatasheet
    Ambient temperature, discharge−25 °C to 65 °CDatasheet
    Ambient temperature, charge−20 °C to 65 °CDatasheet
    Ambient temperature, storage−15 °C to 40 °CDatasheet
    Designed floating life20+ years at 20 °CDatasheet
    Terminal typeFemale copper insert, M8 thread, 20 mm outer diameter, 7 mm thread depthDatasheet
    Terminal tightening torque10–12 N·mDatasheet
    Vent plugsAcid-proof, flame-retardant, explosion-proof; catalytic plug optionalDatasheet
    Applicable standardsIEC 60896-11, DIN 40736, IEC 61427, Eurobat long-life guide, BS 6290 part 4, UL 1989Datasheet
    CertificationsISO 9001, ISO 14001, GB/T 28001, CE, ULDatasheet

    Solar and wind long-time discharge

    For renewable duty the useful capacity is quoted at a lower cut-off voltage, because the controller protects the battery long before the cell reaches 1.80 V. The datasheet publishes the following capacities at a 1.85 V cut-off:

    RateCapacity at 1.85 V per cellSource
    C242,260 AhDatasheet
    C482,480 AhDatasheet
    C722,600 AhDatasheet
    C1002,700 AhDatasheet
    C1202,740 AhDatasheet
    C2402,800 AhDatasheet

    §2 — The Pain: Why Utility DC Purchases Go Wrong

    First, the capacity number without a rate is not a number. The OPzS2-2000 2V2000Ah is rated at C10. A distributor who quotes “2,000 Ah” without the rate is quoting a figure that does not describe your duty. At a one-hour discharge the cell gives roughly half its C10 capacity; at a ten-hour discharge it gives the full figure. A plant that rides out a multi-day wind drought on a slow discharge sits close to the C10 curve, while a ride-through cabinet with a five-minute discharge at high load sees far less. Specify the rate and the cut-off voltage together with the capacity, always.

    Second, flooded means a room, not a container. Hydrogen evolves during charging and needs a path out. Acid-proof flame-retardant vent plugs handle the ignition source; they do not handle the accumulation. Every OPzS2-2000 installation needs mechanical ventilation sized for the worst-case float and equalisation charge, and it needs a person with a hydrometer and a top-up bottle on a schedule. Buyers who treat the OPzS2-2000 2V2000Ah as a drop-in replacement for a sealed block discover the difference in the first hot season.

    Third, charge acceptance quietly caps the whole project. The published maximum charging current for the OPzS2-2000 is 400 A, which is 0.20 C10. At 48 V nominal that is about 19.2 kW. An array sized on the load rather than on the battery is an array the battery cannot absorb. The excess goes into float losses, extended equalisation, or an over-voltage disconnect that takes the inverter out of service. The array is the expensive half of a utility project, so fix this number before the panels are ordered.

    Fourth, the float life is temperature-bound, and the datasheet is specific about it. The designed floating life of 20+ years is stated at 20 °C, and it is roughly halved for every 10 °C above that. A container in Chennai, Durban or Karachi that runs at 30 °C ambient all year is looking at a life closer to ten years, not twenty, and no controller precision changes that. Room cooling is a battery decision, not a comfort decision.

    Fifth, the physical envelope is not negotiable. 399 mm long, 210 mm wide and 826 mm tall over terminals, with 146 kg filled. Rack pitch, aisle width, door clearance and the lifting route for a single cell all have to be confirmed against the drawing before the plinth is poured. Substituting a guess is how a delivery arrives that cannot be installed.

    §3 — The Choice: Where the OPzS2-2000 Sits

    The alternative to the OPzS2-2000 2V2000Ah is rarely another chemistry. In grid-scale renewable, utility telecom and traction markets where this cell is specified, the real choice is the same flooded platform at a different capacity, the gel variant of the same platform, or a sealed VRLA block of a lower capacity.

    Against the neighbouring flooded capacities

    ParameterOPzS2-1500 2V1500AhOPzS2-2000 2V2000AhOPzS2-3000 2V3000Ah
    Rated capacity (C10)1,500 Ah2,000 Ah3,000 Ah
    Cell dimensions275 × 210 × 850 mm399 × 210 × 826 mm576 × 212 × 771 mm
    Total height over terminals850 mm826 mm771 mm
    Weight without electrolyte71.0 kg106 kg155 kg
    Weight with electrolyte98 kg146 kg218 kg
    Internal resistance0.40 mΩ at 20 °C0.35 mΩ at 20 °C0.24 mΩ at 20 °C
    Maximum charging current300 A400 A600 A
    Short-circuit current5,400 A6,000 ANot published
    Float voltage2.23 V per cell2.23 V per cell2.23 V per cell
    Designed float life20+ years at 20 °C20+ years at 20 °C20+ years at 20 °C

    The middle column is the OPzS2-2000 datasheet; the OPzS2-1500 and OPzS2-3000 figures are the published values for those models. Three observations follow directly.

    The OPzS2-2000 absorbs 400 A per cell, so a 48 V string of 24 cells accepts 9,600 A, which covers an array of roughly 19.2 kW on one string. Below that the OPzS2-1500 at 300 A is the natural choice; above it the OPzS2-3000 at 600 A is.

    Internal resistance falls from 0.40 mΩ to 0.24 mΩ across this range, which makes a large string electrically cleaner at the same fault duty and why voltage recovery after a load step is less punishing on the bigger cells.

    Footprints and heights are not shared across the range: 275 × 210, 399 × 210 and 576 × 212 mm with three different heights. A rack built for one cell is not a rack for another, so the OPzS2-2000 drawing governs the aisle and the lifting route.

    The 48 V string arithmetic

    Every number below is derived from the published per-cell figures above.

    Derived quantityCalculationResult
    String nominal energy24 × 2 V × 2,000 Ah96 kWh
    String series resistance24 × 0.35 mΩ8.40 mΩ
    String maximum charging current24 × 400 A9,600 A
    String maximum discharge current (5 s)24 × 3,600 A86,400 A
    String weight filled24 × 146 kg3,504 kg
    String weight dry24 × 106 kg2,544 kg
    String acid weight24 × 40 kg960 kg
    Short-circuit current at the terminals48 V ÷ 8.40 mΩ≈5,700 A

    The last line is a calculation, not a datasheet figure: the published short-circuit current of 6,000 A is the manufacturer’s value for the cell and governs protection coordination. Use the published number for coordination and treat the derived figure as a sanity check on the wiring.

    Flooded against gel

    If nobody will ever touch the battery — no water top-up, no quarterly equalisation, no hydrometer — the gel version of this platform is the better product, and the OPzS2-2000 2V2000Ah is the wrong choice. Gel removes the room requirement: no ventilation path, no topping up, no hydrogen accumulation. The cost is a lower published cycle-life floor and marginally higher internal resistance. Make that trade explicitly, because it is a labour decision as much as a chemistry decision.

    §4 — The Framework: Nine Things to Fix Before the Order

    1. Lock the rate with the capacity. Write “OPzS2-2000 2V2000Ah, 2,000 Ah at C10 to 1.80 V per cell at 20 °C” on the purchase order, not “2,000 Ah”. If the duty is a shorter discharge, ask for the capacity at that rate and at the cut-off voltage the controller will use.

    2. Fix the string architecture on paper first. 24 cells at 2 V gives 48 V nominal, which is the common utility and telecom DC bus. 48 cells gives 96 V. Write the cell count, the nominal bus voltage and the end-point voltage at 1.80 V per cell — 43.2 V for a 24-cell string — next to the load list. Every downstream number, from charger rating to cable cross-section, follows from those three figures.

    3. Check the charge ceiling against the array. Maximum charging current is 400 A per cell, so 9,600 A for a 24-cell string, roughly 19.2 kW at 48 V nominal. If the array exceeds that, step up one capacity in the range or fit a charge-current limit in the controller. Decide before the array is ordered.

    4. Use the renewable setpoint table, not the generic one. For solar and wind the datasheet publishes a dedicated set of controller parameters, and they are not the same as the stationary float-and-equalise pair:

    ParameterValueSource
    Over-voltage disconnect2.47 ± 0.01 V per cellDatasheet
    Regulation / equalise voltage2.40 ± 0.01 V per cellDatasheet
    Array reconnection voltage2.23 ± 0.005 V per cellDatasheet
    Float voltage setting2.25 ± 0.005 V per cellDatasheet
    Low-voltage alarm1.95 ± 0.005 V per cellDatasheet
    Low-voltage disconnect1.90 ± 0.005 V per cellDatasheet
    Load reconnect voltage2.09 ± 0.01 V per cellDatasheet
    Temperature compensation coefficient−4 mV per cell per °CDatasheet

    Note the deliberate difference from the stationary setpoints in §1. The renewable float setting is 2.25 V per cell, not 2.23 V, and the renewable compensation coefficient is −4 mV per cell per °C, not −3 mV. Renewable charging is intermittent, so the controller holds the array at a slightly higher potential to capture what light there is, and the −4 mV coefficient is matched to the wider temperature swing of an outdoor cabinet. Copying the stationary numbers into a solar controller is a common and expensive error.

    5. Design the ventilation path. Hydrogen evolves on charge. Provide mechanical extraction sized for the worst-case charge case, keep flame-retardant acid-proof vent plugs fitted, and confirm the room is not a sealed container with one door.

    6. Schedule the water. An OPzS2-2000 cell loses water on every charge cycle. Quarterly top-up with distilled or demineralised water, a quarterly specific-gravity reading on every cell and a logged equalisation at a defined interval are operating requirements, not maintenance extras. Budget the labour; a battery that is never checked fails at the worst time.

    7. Confirm the mechanical envelope against the drawing. For the OPzS2-2000: 399 × 210 × 826 mm, 146 kg filled, terminal centre spacing 110 × 110 mm, M8 female insert at 10–12 N·m. Rack pitch, door clearances, the lifting route for a 146 kg cell and the floor loading all need the drawing, not a spreadsheet.

    8. Set the end-of-life criterion now. Define the capacity floor — the percentage of rated C10 at which the string is replaced — and put it in the maintenance plan with a date attached. Without a written criterion, end-of-life is a judgement call made under pressure during an outage.

    9. Order the spares policy deliberately. Cells in a series string age unevenly. Decide in advance whether you hold one spare OPzS2-2000 cell on site, and note that a spare must be the same model and age band as the string, not a newer cell dropped into an older string.

    §5 — The Trust: Who Built It and What Is Certified

    CHISEN operates 8 production bases with an annual capacity of 70 million kVAh, which is the scale behind the published datasheet rather than a marketing figure on a web page. The OPzS2-2000 2V2000Ah is built to IEC 60896-11 for stationary lead-acid valves and DIN 40736 for tubular cells, with IEC 61427 and BS 6290 part 4 also applicable and the UL 1989 listing covering the North American side. The Eurobat long-life guide applies to the float-life claim. The manufacturing system is certified to ISO 9001 for quality management and ISO 14001 for environmental management, with GB/T 28001 covering occupational health and safety, and the product carries CE marking. Every export shipment is documented with CE, UL and IEC certification papers for the exact variant.

    Those standards matter commercially, not just decoratively. DIN 40736 and IEC 60896-11 are what an importer’s technical file has to cite for EU market access; BS 6290 part 4 and UL 1989 are what a buyer in Mumbai, Karachi, Durban or a Gulf port asks for when the battery is going into a tender. The same document set is requested in Rotterdam, Hamburg, Jebel Ali, Santos, Mombasa, Antwerp, Colombo and Lagos: the standards are identical, the local authority requirements are not.

    The certification set is a claim you can verify rather than take on trust: request the test certificates for the exact model, check that the scope covers the 2,000 Ah variant, and confirm the certificate address matches the supplier quoting it. Do this before a 24-cell OPzS2-2000 string lands on your floor, because a certificate that does not cover the variant is a documentation problem discovered at the wrong moment.

    The 8 production bases and 70 million kVAh of capacity also matter for delivery risk on a large project. A 48 V string of 24 OPzS2-2000 cells at 146 kg filled is 3,504 kg of battery from one production base, and a mixed-date delivery is a mixed-age string. Ask for the manufacturing date on the cells, and ask that the whole string be produced within one production window.

    §6 — FAQ: OPzS2-2000 2V2000Ah

    Q1. What is the rated capacity of the OPzS2-2000 2V2000Ah? 2,000 Ah at the ten-hour rate, meaning 200 A for 10 hours to a 1.80 V per cell cut-off at 20 °C. The datasheet also publishes renewable long-time discharge capacities at a 1.85 V cut-off, from 2,260 Ah at C24 up to 2,800 Ah at C240.

    Q2. What are the physical dimensions and weight of one OPzS2-2000 cell? 399 × 210 × 826 mm overall, with a 772 mm container and 826 mm height over terminals. 106 kg without electrolyte, 146 kg with electrolyte, and 40 kg of acid at 1.240 g/cm³. One filled cell is a two-person handling job.

    Q3. What float and equalise voltages should the charger use? Float 2.23 V per cell at 25 °C with −3 mV/°C/cell compensation, and equalise 2.35 V per cell at 25 °C over a 20–25 °C range. For solar and wind duty the controller setpoints differ — 2.25 V float and a −4 mV per cell per °C coefficient — and are listed in §4.

    Q4. How much current can the OPzS2-2000 take during charging? The published maximum charging current is 400 A, which is 0.20 C10. A 24-cell 48 V string therefore accepts 9,600 A, roughly 19.2 kW at nominal bus voltage. Exceeding that limit pushes the array into float losses or triggers an over-voltage disconnect.

    Q5. What are the internal resistance and short-circuit current of the OPzS2-2000? Internal resistance is approximately 0.35 mΩ fully charged at 20 °C. The published short-circuit current is 6,000 A, and the maximum discharge current is 3,600 A for 5 s. A 24-cell string presents 8.40 mΩ in series.

    Q6. How long does the OPzS2-2000 2V2000Ah last in float service? The designed floating life is 20+ years at 20 °C. Float life falls by roughly half for every 10 °C above 20 °C, so an uncooled container at 30 °C ambient should expect materially less.

    Q7. What maintenance does the OPzS2-2000 require? Quarterly water top-up with distilled or demineralised water, a quarterly specific-gravity reading on every cell, equalisation on a logged schedule, and hydrogen ventilation sized for the worst-case charge case. Acid-proof flame-retardant vent plugs must stay fitted.

    Q8. Can the OPzS2-2000 2V2000Ah be used for solar storage? Yes, and the datasheet publishes a dedicated setpoint table for renewable duty, including the 2.47 ± 0.01 V over-voltage disconnect, the 2.40 ± 0.01 V regulation voltage and the 1.90 ± 0.005 V low-voltage disconnect. The 400 A maximum charging current still applies, so the array must be sized against it.

    Q9. What certifications does the OPzS2-2000 2V2000Ah carry? Built to IEC 60896-11, DIN 40736, IEC 61427, the Eurobat long-life guide, BS 6290 part 4 and UL 1989. The manufacturing system is certified to ISO 9001 and ISO 14001, with GB/T 28001, and the product carries CE marking and UL documentation.

    Expert Summary

    The OPzS2-2000 2V2000Ah is a 2 V, 2,000 Ah flooded tubular cell for 48 V and 96 V DC strings in utility DC plants, grid-scale renewable installations and major traction substations. Its published envelope is 399 × 210 × 826 mm at 106 kg dry and 146 kg filled, with 0.35 mΩ internal resistance, a 6,000 A short-circuit current and a 400 A maximum charging current.

    Four decisions carry the project. Size on C10 with the cut-off voltage attached to the capacity. Respect the 400 A charge ceiling when the array is specified, or step up one capacity in the range. Use the renewable setpoint table for solar and wind rather than the stationary pair. And budget the labour and ventilation a flooded cell needs, because the 20+ year float life at 20 °C only holds in a maintained, ventilated, temperature-controlled room.

    For a 24-cell 48 V string the arithmetic is 96 kWh nominal, 8.40 mΩ in series, 9,600 A of charge acceptance, 3,504 kg of installed battery and 960 kg of acid. Take those five numbers to the civil and electrical design, and the OPzS2-2000 2V2000Ah will do what the datasheet says it does.

    Contact CHISEN

    Technical enquiries, project drawings and tender documents: sales@chisen.cn and +86 131 6622 6999 on WhatsApp. Mention the model OPzS2-2000 and the string voltage you are designing for, and the CHISEN team will supply the certified per-cell datasheet, the certified weight, the drawing and the test certificates for the exact variant.

    Related reading: the OPzS2-2000 2V2000Ah model page, the OPzS2-1500 2V1500Ah model page for the cell below it in the range, and the OPzS flooded tubular battery range for the full platform.

    Related CHISEN Buyer Guides

  • 12V 200Ah Solar Battery: Build a Bank from 6-EVF-100

    12V 200Ah Solar Battery: Build a Bank from 6-EVF-100

    Answer First

    There is no single 12V 200Ah cell in the CHISEN range, and a buyer who expects one will waste weeks comparing quotations that nobody can honour: the standard way to build a 12V 200Ah solar battery bank is two 12V 100Ah AGM blocks — the 6-EVF-100 — wired in parallel, which gives 12 V × 200 Ah = 2,400 Wh, weighs 2 × 31.5 kg = 63.0 kg and accepts 2 × 20.0 A = 40.0 A of charge current, while the single-unit alternatives inside the same 12V EVF range are the 6-EVF-120, 6-EVF-135 and 6-EVF-150. This guide sets out the published specification of those four cells, shows the arithmetic for the two-unit bank and the 48 V pack built on it, and gives the seven checks to run before you order from a supplier in Hangzhou, Rotterdam, Jebel Ali, Lagos or Chennai.

    Key Takeaways

    • CHISEN publishes no 12V 200Ah model: the 12V 200Ah solar battery bank is two 6-EVF-100 12V 100Ah AGM blocks in parallel, which is 12 V × 200 Ah = 2,400 Wh.
    • The bank weighs 2 × 31.5 kg = 63.0 kg and its maximum charge current is 2 × 20.0 A = 40.0 A; specific energy is 2,400 Wh ÷ 63.0 kg = 38.1 Wh/kg.
    • The published 100 Ah is a C3 rating; the 10-hour rate (C10) is not published on these pages, so a daily cycle sized on a 10-hour discharge must be quoted against a C10 figure the factory still has to supply.
    • Single-unit options in the same range give 1,440 Wh at 36.0 Wh/kg (6-EVF-120), 1,620 Wh at 36.0 Wh/kg (6-EVF-135) and 1,800 Wh at 37.1 Wh/kg (6-EVF-150), against 38.1 Wh/kg for the parallel pair.
    • Float 13.5 V and equalisation 14.1 V for the block — 2.25 V and 2.35 V per cell — are the setpoints to fix in writing; cycle life is published at 350–600 cycles at 50–80 % depth of discharge and design life at 2–5 years.

    §1 — 12V 200Ah Solar Battery Specifications

    The table below reproduces the published specification of the four 12V EVF cells that bracket the 200Ah solar duty, so the bank you specify can be defended line by line at the goods-in dock. Every cell figure comes from the manufacturer model page; derived figures are shown with their formulas.

    Specification6-EVF-1006-EVF-1206-EVF-1356-EVF-150Source
    Nominal voltage12 V12 V12 V12 VModel page
    Rated capacity100 Ah120 Ah135 Ah150 AhModel page
    Discharge rate basisC3 (3 h)C3 (3 h)C3 (3 h)C3 (3 h)Model page
    Dimensions L × W × H330 × 170 × 218 mm407 × 170 × 240 mm338 × 172 × 280 mm483 × 170 × 240 mmModel page
    Weight31.5 ± 0.2 kg40 ± 0.2 kg45 ± 0.2 kg48.5 ± 0.2 kgModel page
    Terminalφ20-M8φ20-M8φ20-M8φ20-M8Model page
    Maximum charge current20.0 A24.0 A27.0 A30.0 AModel page
    Charge current as C-rate20.0 A ÷ 100 Ah = 0.2C24.0 A ÷ 120 Ah = 0.2C27.0 A ÷ 135 Ah = 0.2C30.0 A ÷ 150 Ah = 0.2CArithmetic
    Float charge voltage13.5 V13.5 V13.5 V13.5 VModel page
    Equalisation voltage14.1 V14.1 V14.1 V14.1 VModel page
    Cycle life (DoD 50–80 %)350–600 cycles350–600 cycles350–600 cycles350–600 cyclesModel page
    Cut-off voltage1.75 V/cell1.75 V/cell1.75 V/cell1.75 V/cellModel page
    Self-discharge≤ 3 %/month at 25 °C≤ 3 %/month at 25 °C≤ 3 %/month at 25 °C≤ 3 %/month at 25 °CModel page
    Working temperature−15 °C to 50 °C−15 °C to 50 °C−15 °C to 50 °C−15 °C to 50 °CModel page
    Design life2–5 years2–5 years2–5 years2–5 yearsModel page
    Energy per cell12 V × 100 Ah = 1,200 Wh12 V × 120 Ah = 1,440 Wh12 V × 135 Ah = 1,620 Wh12 V × 150 Ah = 1,800 WhArithmetic
    Specific energy1,200 Wh ÷ 31.5 kg = 38.1 Wh/kg1,440 Wh ÷ 40 kg = 36.0 Wh/kg1,620 Wh ÷ 45 kg = 36.0 Wh/kg1,800 Wh ÷ 48.5 kg = 37.1 Wh/kgArithmetic
    Series build published4 = 48 V, 5–6 = 60–72 V, 8 = 96 V4 = 48 V, 5–6 = 60–72 V, 8 = 96 V4 = 48 V, 5–6 = 60–72 V, 8 = 96 V4 = 48 V, 5–6 = 60–72 V, 8 = 96 VModel page
    Published applicationsSightseeing vehicles, golf carts, forklifts, floor scrubbers, AGVs, electric boatsSightseeing vehicles, golf carts, forklifts, floor scrubbers, AGVs, electric boatsSightseeing vehicles, golf carts, forklifts, floor scrubbers, AGVs, electric boatsSightseeing vehicles, golf carts, forklifts, floor scrubbers, AGVs, electric boatsModel page

    Two rows deserve a note before they go into a purchase order. The float and equalisation figures are block values across the six cells in series, so 13.5 V is 2.25 V per cell and 14.1 V is 2.35 V per cell; a charger set to 14.4 V will shorten service life without adding usable capacity. And the rated capacity is quoted at the three-hour rate, not the rate at which a solar day discharges it.

    §2 — The Pain

    Three failures account for almost every 12V 200Ah solar battery complaint that reaches a distributor’s technical desk in Hamburg, Durban or Mombasa.

    The first is the label. A carton marked “12V 200Ah” tells you nothing about the case, the terminals, the rate basis of the capacity or the charge setpoints. Two suppliers can both print “12V 200Ah AGM” and deliver two different banks: one built from two 100Ah blocks with a published 63.0 kg weight, the other from two lesser cells with no published weight at all. A buyer who quotes capacity alone gets a bank that does not fit the cabinet and does not match the charger.

    The second is the rate basis. A bank assembled from two 100Ah blocks holds 200 Ah at the three-hour rate. A solar day is a ten-hour discharge, and the capacity available in that window is lower than the headline figure. If the bank is sized on the published C3 number and not on a C10 figure, the site runs out of energy before the array is fully used, and the owner blames the battery instead of the sizing. None of the four model pages publishes a ten-hour rate, so that figure has to be requested from the factory in writing.

    The third is wiring. Two blocks in parallel must be matched: equal-length interconnecting leads, the same date code on both units, and a fuse or breaker on each string. A bank built from two units of different age will not share current evenly, and the older cell fails first. Nothing in the model page protects against that; only the assembly instruction does.

    Underneath those three sits a sourcing problem. Buyers in Lagos, Chennai, Cairo and Jakarta regularly receive a quotation listing “12V 200Ah solar battery, top quality, top grade” with no datasheet reference, which makes the order impossible to compare between suppliers and impossible to re-order next season.

    §3 — The Choice

    Choosing the build for a 12V 200Ah solar bank is a trade between four published quantities: the footprint on the cabinet shelf, the weight a technician has to lift, the energy per kilogram, and the charger size. The table below sets the five realistic options against each other.

    12V 200Ah build optionUnits usedNominal energyBank weightSpecific energyCharge currentFootprintSource
    Two 6-EVF-100 in parallel2 × 12V 100Ah12 V × 200 Ah = 2,400 Wh2 × 31.5 kg = 63.0 kg2,400 Wh ÷ 63.0 kg = 38.1 Wh/kg2 × 20.0 A = 40.0 A2 units side by side: 330 + 30 + 330 = 690 mm long × 170 mm wide × 218 mm highArithmetic
    One 6-EVF-1201 × 12V 120Ah12 V × 120 Ah = 1,440 Wh40 kg1,440 Wh ÷ 40 kg = 36.0 Wh/kg24.0 A407 × 170 × 240 mmModel page
    One 6-EVF-1351 × 12V 135Ah12 V × 135 Ah = 1,620 Wh45 kg1,620 Wh ÷ 45 kg = 36.0 Wh/kg27.0 A338 × 172 × 280 mmModel page
    One 6-EVF-1501 × 12V 150Ah12 V × 150 Ah = 1,800 Wh48.5 kg1,800 Wh ÷ 48.5 kg = 37.1 Wh/kg30.0 A483 × 170 × 240 mmModel page
    Four 6-EVF-100 in series, 48 V4 × 12V 100Ah48 V × 100 Ah = 4,800 Wh4 × 31.5 kg = 126.0 kg4,800 Wh ÷ 126.0 kg = 38.1 Wh/kg4 × 20.0 A = 80.0 A4 side by side: 330 mm long × 4 × 170 = 680 mm wide × 218 mm highArithmetic

    Read the table as four answers to four different questions. In the single-unit rows the weight, charge current and footprint are published model-page values; the energy and specific-energy columns are derived from them and shown with their formulas.

    If the site genuinely needs 200 Ah at 12 V, the parallel pair of 6-EVF-100 blocks is the only build in the table that delivers it: 2,400 Wh at 63.0 kg and 38.1 Wh/kg, the best specific energy of the 12V options listed. The full cell data sits on the 6-EVF-100 model page, and the 6-EVF-150 model page carries the reference cell most distributors already hold.

    If the cabinet is narrow and the load can live with 150 Ah, the single 6-EVF-150 wins on simplicity: one block instead of two, one string instead of two parallel strings, and 37.1 Wh/kg against 38.1 Wh/kg for the pair. It also carries a published cycle rating of 350–600 cycles at 50–80 % depth of discharge compliant with GB/T 32620.1 — the standard written into the model page rather than into a marketing sheet.

    If the site runs at 48 V — normal for a telecom cabinet or a larger solar house — four cells in series give 48 V × 100 Ah = 4,800 Wh at 126.0 kg and require an 80.0 A charger, set by the published maximum charge current of 20.0 A per cell rather than by rule of thumb.

    If the footprint rather than the weight binds, note that the two-unit bank is longer but lower: 690 mm across two housings at 218 mm high, against 483 mm long and 240 mm high for a single 6-EVF-150. On a 680 mm shelf a four-cell 48V string fits; on a 700 mm shelf the 690 mm pair fits; on a 500 mm bracket only a single block fits.

    §4 — The Framework

    Seven checks turn a vague enquiry into an order a factory can fill correctly.

    1. Ask for the published figure set, not the label. Require capacity with its rate basis, dimensions in millimetres, weight with tolerance, terminal type, float and equalisation voltage, maximum charge current, cycle rating, cut-off voltage and working temperature. A supplier that answers all ten is not guessing; one that answers “12V 200Ah AGM” is.

    2. Fix the rate basis before the capacity. Ask for the capacity at the ten-hour rate for the duty you actually have, and treat a supplier who cannot supply it as one who has not read the cell. The published C3 figures in §1 are correct; they answer a different question.

    3. Write the charge setpoints into the order. 13.5 V float and 14.1 V equalisation for the block, 2.25 V and 2.35 V per cell once the arithmetic is done. Confirm the controller can be configured to both, confirm the equalisation period and confirm the temperature-compensation input if the cabinet runs hot. A 25 °C setpoint in a 45 °C cabinet is an over-charge condition.

    4. Size the charger from the published charge current. The 6-EVF-100 accepts 20.0 A, so a two-block bank needs 2 × 20.0 A = 40.0 A, which is 0.2C on a 200 Ah bank. A smaller charger stretches the recharge window and leaves the bank partly discharged for longer.

    5. Check the temperature envelope and the ventilation. The published working range is −15 °C to 50 °C and capacity is quoted at 25 °C. A cabinet in Chennai, Jebel Ali or Santos will not see 25 °C for most of the year; ask what capacity remains at the extremes and confirm the ventilation.

    6. Specify the parallel assembly. Equal-length leads, matched date codes, one breaker per string, and the same cell in both strings of every bank. Put this on the order acknowledgement, because it is the part the factory cannot see when the container is sealed.

    7. Agree the acceptance test on arrival. For shipments into Rotterdam, Jebel Ali, Lagos or Port Said, state what happens on arrival: a sample capacity check at the agreed rate, a float voltage check across the block, and the rule that a failing sample is settled by re-inspection at an agreed laboratory.

    §5 — The Trust

    These cells are built on a VRLA line inside a manufacturer operating 8 production bases with an annual capacity of 70 million kVAh, under ISO 9001 and ISO 14001 certification, with CE, UL and IEC conformity for the markets each cell ships into. Every figure here comes from an individual model page rather than a catalogue summary, and the wider 12V range sits on the CHISEN 12V VRLA product index.

    Two points deserve emphasis for a buyer who is being asked to pay for assurance. First, a certificate covers a system, a scope and a date — ISO 9001 certifies that the quality management system is documented and that corrective action happens; it does not certify that one cell holds 100 Ah at C3. That is what the published capacity, the type test and the acceptance test are for. Ask for the certificate number, the scope statement and the validity dates.

    Second, the difference between a published specification and a marketing line is the whole value of this exercise. A supplier who quotes “12V 200Ah solar battery, premium quality” is telling you nothing. A supplier who quotes “6-EVF-100 × 2 in parallel, 12 V 200 Ah at C3, 2,400 Wh, 63.0 kg, 40.0 A maximum charge current, float 13.5 V, equalisation 14.1 V” is telling you everything you need to draw the cabinet, size the charger and defend the claim at the goods-in dock.

    For importers who buy through a distributor rather than direct, ask for the manufacturer’s model page URL and the batch reference. Both can be checked before the container is opened, and both remove the largest source of dispute in this category.

    §6 — FAQ

    Q1. Is there a 12V 200Ah battery model? No. CHISEN publishes 12V cells from 12 Ah upward in the 6-DZF and 6-DMF series and from 24 Ah upward in the 6-EVF series, and the largest published 12V cell is the 6-EVF-150 at 150 Ah. No single cell is rated 200 Ah at 12 V, so a 12V 200Ah bank has to be assembled from two 100 Ah blocks in parallel, which is what this guide sizes.

    Q2. How many 12V 100Ah batteries do I need for 200Ah? Two, wired in parallel. In parallel the voltage stays at 12 V and the capacity adds: 12 V × 200 Ah = 2,400 Wh. In series the capacity stays at 100 Ah and the voltage doubles to 24 V. Parallel requires equal-length leads and matched cells; series requires matched voltage at the start of the string.

    Q3. What does the bank weigh? 2 × 31.5 kg = 63.0 kg for two 6-EVF-100 blocks, plus busbars, insulators and the cabinet. A single 6-EVF-150 weighs 48.5 kg and a 6-EVF-135 weighs 45 kg, so the parallel pair is 14.5 kg heavier than one 150 Ah cell and 18.0 kg heavier than one 135 Ah cell, while carrying 50 Ah and 65 Ah more at 12 V.

    Q4. What charger do I need for a 12V 200Ah bank? A 12 V charger with a 40.0 A output, because the published maximum charge current is 20.0 A per cell and 2 × 20.0 A = 40.0 A. That is 0.2C on a 200 Ah bank, and the recharge window at that current is 200 Ah ÷ 40.0 A = 5.0 hours. Set float at 13.5 V and equalisation at 14.1 V for the block.

    Q5. Is the published 100 Ah usable for a solar day? The published figure is a C3 rating. On a ten-hour discharge the usable capacity is lower, and the ten-hour rate is not published on the model page. Size the array on a figure the factory supplies in writing at the ten-hour rate, or apply the derating your own engineering standard requires.

    Q6. Which is better for solar standby, a 12V 200Ah AGM bank or a 48V bank of four cells? Different tools. A 12V 200Ah bank gives 2,400 Wh at 63.0 kg and needs a 40.0 A charger; a 48V bank of four 6-EVF-100 cells gives 4,800 Wh at 126.0 kg and needs an 80.0 A charger. The 48V string halves the cable current for the same power and is the normal choice above about 2 kW of load.

    Q7. How long will a 12V 200Ah solar battery bank last? In float standby with solar charging, the published design life is 2–5 years and the cycle rating 350–600 cycles at 50–80 % depth of discharge. In solar duty the binding factor is usually the number of cycles the site sees, not the calendar. A site in Chennai or Jebel Ali will find the temperature envelope as decisive as the cycle count.

    Q8. Can I mix a 6-EVF-100 and a 6-EVF-120 in the same bank? Technically the voltages are equal, but the capacities are not, and the 20.0 A and 24.0 A charge-current figures differ. Current in a parallel pair divides by capacity, so the smaller cell carries more than its share. Keep a bank on identical cells, or on matched strings with the same capacity and date code.

    Q9. What should be on the purchase order for a 12V 200Ah solar battery bank? The cell model and quantity, the parallel arrangement, the float and equalisation voltages, the maximum charge current, the rate basis of the capacity, the cycle rating and depth of discharge, the terminal type, the date code match, the test certificate and the acceptance procedure on arrival. For Rotterdam, Santos or Mombasa, name the agreed laboratory for a failing-sample inspection.

    Q10. Do I need a temperature-compensated charger? For a cabinet that regularly exceeds 30 °C, yes. The published float voltage of 13.5 V assumes 25 °C, and a fixed setpoint in a hot cabinet is an over-charge condition that shows up as shortened service life and more frequent water loss rather than as a fault report.

    Expert Summary

    A 12V 200Ah solar battery bank is a build, not a product code: two 6-EVF-100 12V 100Ah AGM blocks in parallel, giving 12 V × 200 Ah = 2,400 Wh at 2 × 31.5 kg = 63.0 kg, a specific energy of 2,400 Wh ÷ 63.0 kg = 38.1 Wh/kg, and a maximum charge current of 2 × 20.0 A = 40.0 A. The published specification behind that build is 12 V, 100 Ah at C3, 330 × 170 × 218 mm, 31.5 ± 0.2 kg, float 13.5 V, equalisation 14.1 V, 350–600 cycles at 50–80 % depth of discharge and 2–5 years design life; the single-unit alternatives are the 6-EVF-120, 6-EVF-135 and 6-EVF-150.

    The commercial value of specifying precisely exceeds the price difference between the builds. A quotation written against published figures can be compared across three suppliers in ten minutes and defended at the goods-in dock. One written against a label cannot be compared at all, and the difference appears three months later as a warranty claim.

    Two figures deserve a final emphasis for buyers working outside Europe. First, the 40.0 A charger requirement comes from the published charge current, not from marketing: if the charger is smaller, the recharge window stretches and the bank spends more of its life half-discharged, which is the condition that sulphates a plate. Second, the published capacity is a C3 figure and the ten-hour rate is not published, so any solar array sized on the headline number is sized on the wrong number until the factory supplies the rate for your duty.

    For importers into markets served from Rotterdam, Jebel Ali, Santos, Lagos or Chennai, the sequence that works is simple: fix the published specification first, then let suppliers compete on it. The §1 figure set is enough to run that process.

    Contact CHISEN

    Send the target application, the required capacity at the discharge rate you actually have, the cabinet dimensions you need to fit and the quantity to the CHISEN export desk, and you will receive a quotation against the published specification, the datasheet and the lead time.

    • Email: jack@chisen.cn or sales@chisen.cn
    • WhatsApp: +86 131 6622 6999
    • 6-EVF-100 model page: https://www.chisen.cn/en/6-EVF-100/12V100Ah.html
    • 6-EVF-150 model page: https://www.chisen.cn/en/6-EVF-150/12V150Ah.html
    • 12V VRLA product index: https://www.chisen.cn/en/LeadacidBattery/EVF.html

    Related reading on the CHISEN knowledge centre: 12V VRLA selection guidance, deep-cycle charge setpoints, and pack-sizing method for solar house and telecom applications.

    CHISEN Battery — lead-acid cells and systems for telecom, solar, UPS, AGV and traction applications. 8 production bases, 70 million kVAh annual capacity, ISO 9001 and ISO 14001 certified.

    Related CHISEN Buyer Guides

  • 12V 32Ah E-Bike Battery: 6-DMF-32 Against 6-DZF-20 and the 35Ah / 38Ah Options (2026)

    12V 32Ah E-Bike Battery: 6-DMF-32 Against 6-DZF-20 and the 35Ah / 38Ah Options (2026)

    Answer First

    A 12V 32Ah e-bike battery is not one published product, and that decides your order: CHISEN publishes electric bicycles, e-bikes and electric wheelchairs on the 6-DZF-20 at 12V 20 Ah, while the published 12V 32 Ah cell is the 6-DMF-32, rated for passenger and freight electric tricycles, electric motorcycles and mopeds, electric sanitation trucks and sprayers, and electric sightseeing vehicles. The two are also quoted on different rate bases — 20 Ah at C2 (2 h) for the 6-DZF-20 against 32 Ah at C3 (3 h) for the 6-DMF-32 — so any comparison that places the amp-hour numbers side by side without naming the discharge rate is wrong.

    That splits the search term into two intents. A buyer typing “12V 32Ah e-bike battery” is often chasing a 32 Ah traction pack for a pedal e-bike or a light two-wheeler, while a buyer whose real duty is a passenger or freight e-tricycle, a motorbike or a sprayer sits closer to the published 6-DMF-32 figure set. This guide puts the four published cells side by side, shows the 48V pack and charger arithmetic with every formula visible, and gives seven checks to run before an order reaches a supplier serving Hamburg, Rotterdam, Jebel Ali, Lagos, Chennai or Mombasa.

    Key Takeaways

    • The published 12V 32 Ah cell is the 6-DMF-32 for tricycles, motorcycles and mopeds; the published e-bike and wheelchair cell is the 6-DZF-20 at 12V 20 Ah, so match the duty to the model page before the capacity.
    • Rate basis comes before the amp-hour number: 20 Ah at C2 (2 h) and 32 Ah at C3 (3 h) are not directly comparable, and a quotation that omits the rate basis is incomplete.
    • The 6-DMF-32 publishes 12 V × 32 Ah = 384 Wh at 9.1 ± 0.2 kg, which is 384 Wh ÷ 9.1 kg = 42.2 Wh/kg; the 6-DZF-20 gives 240 Wh ÷ 6.1 kg = 39.3 Wh/kg, the 6-DMF-35 gives 420 Wh ÷ 9.8 kg = 42.9 Wh/kg and the 6-DMF-38 gives 456 Wh ÷ 10.45 kg = 43.6 Wh/kg.
    • A 48V pack of four 6-DMF-32 cells weighs 4 × 9.1 kg = 36.4 kg, stores 48 V × 32 Ah = 1,536 Wh and needs a 4 × 6.4 A = 25.6 A charger; the four-cell 6-DZF-20 pack is 24.4 kg, 960 Wh and 16.0 A.
    • Float 13.5 V, equalisation 14.1 V, cut-off 1.75 V/cell, 350–600 cycles at 50–80 % depth of discharge and a 2–5 year design life describe this class of cell — the acceptance test confirms them.

    §1 — 12V 32Ah E-Bike Battery Specifications

    The published figure set below is the whole decision: the 6-DMF-32 at 12V 32 Ah, the 6-DZF-20 at 12V 20 Ah, and the two capacity steps above it, the 6-DMF-35 and the 6-DMF-38. Model-page values first, then every derived figure with its formula.

    Specification6-DMF-326-DZF-206-DMF-356-DMF-38Source
    Nominal voltage12 V12 V12 V12 VModel page
    Rated capacity32 Ah20 Ah35 Ah38 AhModel page
    Discharge rate basisC3 (3 h)C2 (2 h)C3 (3 h)C3 (3 h)Model page
    Dimensions L × W × H267 × 78 × 170 mm180 × 76 × 170 mm267 × 78 × 170 mm224 × 106 × 175 mmModel page
    Weight9.1 ± 0.2 kg6.1 ± 0.2 kg9.8 ± 0.2 kg10.45 ± 0.2 kgModel page
    Terminalφ8.8-M5φ8.8-M5φ8.8-M5φ9.8-M5Model page
    Charging current6.4 A4.0 A7.0 A7.6 AModel page
    Float charge voltage13.5 V13.5 V13.5 V13.5 VModel page
    Equalisation voltage14.1 V14.1 V14.1 V14.1 VModel page
    Cycle life350–600 cycles (DoD 50–80 %)350–600 cycles (DoD 50–80 %)350–600 cycles (DoD 50–80 %)350–600 cycles (DoD 50–80 %)Model page
    Published applicationsElectric tricycles, motorcycles, mopeds, sanitation truck, sprayer, sightseeing vehicleElectric bicycles, e-bikes, electric wheelchairsElectric tricycles, motorcycles, mopedsElectric tricycles, motorcycles, mopedsModel page
    Energy per cell12 V × 32 Ah = 384 Wh12 × 20 = 240 Wh12 × 35 = 420 Wh12 × 38 = 456 WhArithmetic
    Specific energy per cell384 Wh ÷ 9.1 kg = 42.2 Wh/kg240 Wh ÷ 6.1 kg = 39.3 Wh/kg420 Wh ÷ 9.8 kg = 42.9 Wh/kg456 Wh ÷ 10.45 kg = 43.6 Wh/kgArithmetic
    Footprint area L × W267 × 78 = 20,826 mm²180 × 76 = 13,680 mm²267 × 78 = 20,826 mm²224 × 106 = 23,744 mm²Arithmetic
    Recharge time at published charge current32 Ah ÷ 6.4 A = 5.0 h20 Ah ÷ 4.0 A = 5.0 h35 Ah ÷ 7.0 A = 5.0 h38 Ah ÷ 7.6 A = 5.0 hArithmetic

    The 6-DMF-35 model page also publishes the operating envelope for this class of cell: a cut-off voltage of 1.75 V/cell, self-discharge of ≤ 3 % per month at 25 °C, a working temperature range of −15 °C to 50 °C, a design life of 2–5 years, and an ABS engineering plastic case at flame retardant V0 grade.

    §2 — The Pain

    The reason a 12V 32Ah e-bike battery enquiry goes wrong is almost never the cell: the search term, the published application list and the published rate basis point in three directions, and a buyer who does not separate them buys the wrong model.

    The first failure is the application mismatch. A buyer searching for a 32 Ah pack for a pedal e-bike or a light two-wheeler finds that the published e-bike duty — electric bicycles, e-bikes and electric wheelchairs — sits on a 12V 20 Ah cell, while the published 12V 32 Ah cell carries a different duty list: passenger and freight e-tricycles, electric sanitation trucks and sprayers, electric motorcycles and mopeds, and electric sightseeing vehicles. Neither cell is published for the other’s job, so the substitution must be made against the vehicle duty, not inferred from the amp-hour number.

    The second failure is the rate basis. A spreadsheet that compares 32 Ah against 20 Ah without the rate treats two different discharge conditions as one, and the gap it reports is not a gap the buyer will ever see on the road. The same error shows up in the charger decision: the 6-DMF-32 publishes a 6.4 A charging current while the 6-DZF-20 publishes 4.0 A, and a charger sized on Ah alone will over- or under-drive the pack.

    The third failure is mechanical. A 48V pack of four 6-DMF-32 cells weighs 36.4 kg, while the same pack built from four 6-DZF-20 cells weighs 24.4 kg — a difference of 4 × (9.1 kg − 6.1 kg) = 12.0 kg per pack. The footprint difference is equally direct: 267 × 78 = 20,826 mm² against 180 × 76 = 13,680 mm², so the 32 Ah cell needs 20,826 mm² − 13,680 mm² = 7,146 mm² more tray per cell. On a two-wheeler frame, those two numbers decide whether the vehicle ships or waits for a redesigned tray.

    Under all three sits a sourcing failure. Buyers importing into Lagos, Chennai, Jebel Ali or Mombasa regularly receive a quotation line reading “12V 32Ah e-bike battery, top grade” with no model code, rate basis, dimensions or charge current — a line that cannot be compared across suppliers or defended at the dock.

    §3 — The Choice

    Choosing between these four cells is a trade between four published quantities: rate basis and capacity, case footprint, weight, and the charging current that follows from it. The table below sets them against the criteria that move a purchase order.

    Decision criterion6-DMF-326-DZF-206-DMF-356-DMF-38Source
    Capacity and rate basis32 Ah at C3 (3 h)20 Ah at C2 (2 h)35 Ah at C3 (3 h)38 Ah at C3 (3 h)Model page
    Published dutyTricycles, motorcycles, mopeds, sanitation and sprayer vehicles, sightseeing vehiclesElectric bicycles, e-bikes, electric wheelchairsTricycles, motorcycles, mopedsTricycles, motorcycles, mopedsModel page
    Case footprint267 × 78 × 170 mm180 × 76 × 170 mm267 × 78 × 170 mm224 × 106 × 175 mmModel page
    Weight per cell9.1 ± 0.2 kg6.1 ± 0.2 kg9.8 ± 0.2 kg10.45 ± 0.2 kgModel page
    Terminalφ8.8-M5φ8.8-M5φ8.8-M5φ9.8-M5Model page
    Charge current6.4 A4.0 A7.0 A7.6 AModel page
    Charger for a 48V pack of four4 × 6.4 A = 25.6 A4 × 4.0 A = 16.0 A4 × 7.0 A = 28.0 A4 × 7.6 A = 30.4 AArithmetic
    Energy per cell12 V × 32 Ah = 384 Wh12 × 20 = 240 Wh12 × 35 = 420 Wh12 × 38 = 456 WhArithmetic
    Weight difference against the 6-DZF-209.1 kg − 6.1 kg = 3.0 kg per cell6.1 kg − 6.1 kg = 0 kg9.8 kg − 6.1 kg = 3.7 kg per cell10.45 kg − 6.1 kg = 4.35 kg per cellArithmetic
    Footprint difference against the 6-DZF-2020,826 mm² − 13,680 mm² = 7,146 mm²13,680 mm² − 13,680 mm² = 0 mm²20,826 mm² − 13,680 mm² = 7,146 mm²23,744 mm² − 13,680 mm² = 10,064 mm²Arithmetic

    The 48V pack table turns those cells into the build a buyer specifies. Four 12V blocks in series give a 48V pack, and the published charge current of each cell sets the charger size.

    48V pack buildCells usedPack energyPack weightCharger outputRecharge windowSource
    Four 6-DMF-324 × 12V 32Ah48 V × 32 Ah = 1,536 Wh4 × 9.1 kg = 36.4 kg4 × 6.4 A = 25.6 A32 Ah ÷ 6.4 A = 5.0 hArithmetic
    Four 6-DZF-204 × 12V 20Ah48 V × 20 Ah = 960 Wh4 × 6.1 kg = 24.4 kg4 × 4.0 A = 16.0 A20 Ah ÷ 4.0 A = 5.0 hArithmetic
    Four 6-DMF-354 × 12V 35Ah48 V × 35 Ah = 1,680 Wh4 × 9.8 kg = 39.2 kg4 × 7.0 A = 28.0 A35 Ah ÷ 7.0 A = 5.0 hArithmetic
    Four 6-DMF-384 × 12V 38Ah48 V × 38 Ah = 1,824 Wh4 × 10.45 kg = 41.8 kg4 × 7.6 A = 30.4 A38 Ah ÷ 7.6 A = 5.0 hArithmetic

    Read those two tables as four answers to four questions. If your vehicle is a passenger e-tricycle, a freight e-tricycle, a motorbike, a moped or a sanitation vehicle, the 6-DMF-32 is the published match and the only one of the four carrying the published 32 Ah figure set. The complete specification, including the 267 × 78 × 170 mm case, the 9.1 ± 0.2 kg weight and the φ8.8-M5 terminal, sits on the 6-DMF-32 model page.

    If your vehicle is a pedal e-bike or an electric wheelchair, the published match is the 6-DZF-20 at 180 × 76 × 170 mm and 6.1 ± 0.2 kg, and no published 12V 32 Ah e-bike cell exists in this range; the 6-DZF-20 model page states its 20 Ah at C2 (2 h) rating and its electric bicycles, e-bikes and electric wheelchairs duty directly.

    If the frame is built around the 6-DMF-32 tray and you want more headroom, the 6-DMF-35 is published in the identical 267 × 78 × 170 mm case at 9.8 ± 0.2 kg, so the tray stays while the charger grows from 25.6 A to 28.0 A. If the box has room for a wider case, the 6-DMF-38 moves to 224 × 106 × 175 mm at 10.45 ± 0.2 kg and carries the φ9.8-M5 terminal, so cable hardware and contact torque both change. The wider DZF and DMF traction range is listed on the DZF-DMF series index.

    §4 — The Framework

    Seven checks turn a vague enquiry into an order a factory can fill.

    1. Demand the published figure set, not the label. Ask for capacity with its rate basis, dimensions in millimetres, weight with tolerance, terminal type, float voltage, equalisation voltage, charging current, cycle life and cut-off voltage. For the 6-DMF-32 that means 32 Ah at C3 (3 h), 267 × 78 × 170 mm, 9.1 ± 0.2 kg, φ8.8-M5, 13.5 V, 14.1 V, 6.4 A and 350–600 cycles.

    2. Settle the rate basis before comparing amp-hours. The 6-DZF-20 publishes 20 Ah at C2 (2 h) and the 6-DMF-32 publishes 32 Ah at C3 (3 h), so the two amp-hour figures describe different discharge conditions. Put the rate on the purchase order next to the capacity and refuse any quotation that leaves it off.

    3. Size the charger from the published charge current, not the amp-hour number. The 6-DMF-32 publishes a 6.4 A charging current, so a 48V pack of four needs a 4 × 6.4 A = 25.6 A charger. A charger sized for the 20 Ah cell — 4 × 4.0 A = 16.0 A — is 9.6 A short, and at that reduced current the recharge window becomes 32 Ah ÷ 4.0 A = 8.0 h instead of the published 32 Ah ÷ 6.4 A = 5.0 h. Write the charger output into the order.

    4. Put the float and equalisation setpoints into the order, not into the controller defaults. The published setpoints are 13.5 V float and 14.1 V equalisation for the block, which is 2.25 V per cell and 2.35 V per cell across the six cells, with a cut-off of 1.75 V/cell. Confirm in writing that the controller can be configured to both values, along with the equalisation period and temperature compensation. A controller left on a 14.4 V default over-charges every cell in the pack.

    5. Measure the case footprint and the terminal before the tray is cut. The 6-DMF-32 publishes 267 × 78 × 170 mm with a total height of 170 mm and a φ8.8-M5 terminal, so the cell occupies 20,826 mm² of tray area and 7,146 mm² more than the 6-DZF-20. Lead length, terminal type and hold-down position belong on the frame drawing, and the 6-DMF-38 at φ9.8-M5 needs different cable hardware.

    6. Check the mounting, the case material and the vibration duty on a two-wheeler. The case material published for this class of cell is ABS engineering plastic at flame retardant V0 grade, and the working temperature range is −15 °C to 50 °C. A tricycle or motorbike frame sees continuous vibration, so confirm the hold-down arrangement and that the 36.4 kg pack is carried by the chassis rather than by the tray skin.

    7. Agree the acceptance test on arrival. For shipments landing at Rotterdam, Hamburg, Port Said, Jebel Ali, Lagos, Chennai, Santos, Valencia, Durban or Mombasa, specify in the contract what happens on arrival: a sample capacity check at the published rate, a float voltage check across the block, a visual and torque check on the terminals, and the rule that a failing sample goes to re-inspection at an agreed laboratory rather than to an argument at the dock.

    §5 — The Trust

    The 6-DMF-32, the 6-DZF-20, the 6-DMF-35 and the 6-DMF-38 are built on a VRLA line inside a manufacturer operating 8 production bases with an annual capacity of 70 million kVAh, under ISO 9001 and ISO 14001 certification, with CE, UL and IEC conformity for the markets each cell ships into. The 12V VRLA products in this class are specified against GB/T 32620.1-2016 and GB/T 32620.2-2016 and IEC 60896-21/22, while IEC 60896-11 covers tubular-plate cells, a construction this 12V block class does not use; GB/T 32620.1 also appears on the 6-EVF-150 model page. No certificate number is quoted here because none should be invented, and the certificates themselves are requested with their scope, address and validity dates.

    Two points deserve emphasis for a buyer asked to pay for assurance. First, a certification covers a system, a scope and a date, not a particular carton: ISO 9001 certifies that the quality management system is documented and that corrective action happens, but not that one cell holds 32 Ah at C3. That is what the published capacity, the type test and the acceptance test are for.

    Second, the difference between a published specification and a marketing line is the entire value of this exercise. A supplier who quotes “12V 32Ah e-bike battery, top grade” tells you nothing about rate basis, case, weight or charge current. A supplier who quotes “6-DMF-32, 32 Ah at C3 (3 h), 267 × 78 × 170 mm, 9.1 ± 0.2 kg, φ8.8-M5, float 13.5 V, equalisation 14.1 V, 6.4 A charging current, 350–600 cycles at 50–80 % DoD” tells you everything needed to engineer the pack, write the charger setting and defend the claim at the goods-in dock. For importers buying through a distributor rather than direct, ask for the manufacturer’s model page URL and the batch reference; both can be checked before the container is opened.

    §6 — FAQ

    Q1. Is the 6-DMF-32 suitable for a pedal e-bike? The published application list for the 6-DMF-32 covers passenger and freight electric tricycles, electric sanitation trucks and sprayers, electric motorcycles and mopeds, and electric sightseeing vehicles. It does not include pedal e-bikes. The published e-bike and wheelchair duty in this class sits on the 6-DZF-20 at 12V 20 Ah, so if your vehicle is a pedal e-bike or an electric wheelchair, the specification to work from is the 20 Ah cell and its rate basis, not the 32 Ah cell.

    Q2. What does 32 Ah actually mean on a 12V 32Ah battery? It means 32 amp-hours delivered at the C3 discharge rate — the three-hour rate — down to a cut-off of 1.75 V/cell, at 25 °C. It does not mean 32 Ah for the whole day: on a longer discharge the usable figure is lower, and on a shorter one it is higher, which is why a quotation giving capacity without the rate is incomplete.

    Q3. Can I compare the 20 Ah 6-DZF-20 directly with the 32 Ah 6-DMF-32? Not on capacity alone. The 20 Ah figure is a C2 (2 h) rating and the 32 Ah figure is a C3 (3 h) rating, so they are two different discharge conditions. Compare them on the published envelope instead: case footprint, weight, terminal, charging current and application list. Where you do compare energy, use 12 V × 20 Ah = 240 Wh and 12 V × 32 Ah = 384 Wh, and say so on the order.

    Q4. What charger do I need for a 48V pack of four 12V 32Ah batteries? A 48V charger with a 25.6 A output, because the published charging current is 6.4 A per cell and 4 × 6.4 A = 25.6 A. Set the float at 13.5 V and equalisation at 14.1 V for the 48V string, which is 2.25 V and 2.35 V per cell, with a cut-off of 1.75 V/cell. At the published current the recharge window is 32 Ah ÷ 6.4 A = 5.0 h; at a 16.0 A charger it stretches to 32 Ah ÷ 4.0 A = 8.0 h.

    Q5. Can I fit a 6-DMF-35 where a 6-DMF-32 already sits? Usually yes on the case footprint, because both are published at 267 × 78 × 170 mm with a total height of 170 mm. The differences are weight, at 9.8 ± 0.2 kg against 9.1 ± 0.2 kg, and the charger, at 4 × 7.0 A = 28.0 A against 25.6 A, with 48 V × 35 Ah = 1,680 Wh against 1,536 Wh per pack. The terminal stays at φ8.8-M5, so the cable hardware is unchanged.

    Q6. What is the difference between the 6-DMF-32 and the 6-DMF-38? Capacity, case and terminal. The 6-DMF-38 publishes 38 Ah at C3, 224 × 106 × 175 mm, 10.45 ± 0.2 kg and a φ9.8-M5 terminal, against 32 Ah at C3, 267 × 78 × 170 mm, 9.1 ± 0.2 kg and φ8.8-M5 for the 6-DMF-32. That means a different tray shape, 1.35 kg more mass per cell — 5.4 kg more on a 48V pack of four — a different cable terminal, and a charger of 4 × 7.6 A = 30.4 A instead of 25.6 A.

    Q7. How long will a 12V 32Ah e-bike battery last in service? The published cycle life is 350–600 cycles at 50–80 % depth of discharge, and the published design life is 2–5 years. The cycle figure assumes that depth-of-discharge window, so if your duty runs the pack deeper, ask for the rating at your actual depth before committing to a volume. The calendar figure also assumes the published temperature envelope of −15 °C to 50 °C, with self-discharge at ≤ 3 % per month at 25 °C.

    Q8. What should be on the purchase order for a 12V 32Ah battery? The model code, the rate basis, the case dimensions, the weight tolerance, the terminal type, the float and equalisation voltages, the charging current, the cycle rating and depth of discharge, the batch reference, the test certificate and the arrival acceptance procedure. If the order ships to Rotterdam, Santos, Jebel Ali or Mombasa, name the agreed laboratory for a failing-sample inspection so the dispute path is written before the container sails.

    Expert Summary

    A 12V 32Ah e-bike battery has to be separated into two distinct products before anything else is decided. CHISEN publishes its e-bike, electric bicycle and electric wheelchair duty on the 6-DZF-20 at 12V 20 Ah, rated at 20 Ah on the C2 (2 h) rate, 180 × 76 × 170 mm, 6.1 ± 0.2 kg, φ8.8-M5, 4.0 A charging current. The published 12V 32 Ah cell is the 6-DMF-32, rated at 32 Ah on the C3 (3 h) rate, 267 × 78 × 170 mm, 9.1 ± 0.2 kg, φ8.8-M5, 6.4 A charging current, with its published applications in passenger and freight electric tricycles, electric sanitation trucks and sprayers, electric motorcycles and mopeds, and electric sightseeing vehicles. Neither cell is published for the other’s duty.

    The arithmetic is what a buyer can act on. Four 6-DMF-32 cells give a 48 V × 32 Ah = 1,536 Wh pack at 4 × 9.1 kg = 36.4 kg, needing a 4 × 6.4 A = 25.6 A charger and a 32 Ah ÷ 6.4 A = 5.0 h recharge window; four 6-DZF-20 cells give 48 V × 20 Ah = 960 Wh at 4 × 6.1 kg = 24.4 kg with a 4 × 4.0 A = 16.0 A charger and the same 5.0 h window; the 6-DMF-35 and 6-DMF-38 take those packs to 1,680 Wh and 1,824 Wh at 39.2 kg and 41.8 kg. All four publish float 13.5 V, equalisation 14.1 V, a 1.75 V/cell cut-off and 350–600 cycles at 50–80 % DoD.

    For importers serving Rotterdam, Hamburg, Lagos, Chennai, Jebel Ali, Santos, Port Said, Valencia, Durban and Mombasa, the sequence that works is simple: fix the published figure set first, then let suppliers compete on it. The manufacturer behind these cells operates 8 production bases at 70 million kVAh annual capacity under ISO 9001 and ISO 14001 certification, with CE, UL and IEC conformity for the destination markets, and VRLA cells specified against GB/T 32620.1-2016, GB/T 32620.2-2016 and IEC 60896-21/22. The §1 table runs that process, and the seven checks in §4 prevent a mis-specified order reaching a factory.

    Contact CHISEN

    Send the target vehicle or application, the published capacity you need with its rate basis, the case dimensions your tray allows, the terminal type and the pack quantity, and you will receive a quotation against the published specification, the datasheet and the current lead time.

    • Email: jack@chisen.cn or sales@chisen.cn
    • WhatsApp: +86 131 6622 6999
    • 6-DMF-32 model page: https://www.chisen.cn/en/6-DMF-32/12V32Ah.html
    • 6-DZF-20 model page: https://www.chisen.cn/en/6-DZF-20/12V20Ah.html
    • 6-DMF-35 model page: https://www.chisen.cn/en/6-DMF-35/12V35Ah.html
    • 6-DMF-38 model page: https://www.chisen.cn/en/6-DMF-38/12V38Ah.html
    • DZF-DMF traction series index: https://www.chisen.cn/en/Leadacidbattery/DZF-DMF.html

    Related reading on the CHISEN knowledge centre: 12V VRLA selection guidance, deep-cycle charge setpoints, and pack-sizing method for tricycle, motorcycle and mobility applications.

    CHISEN Battery — lead-acid cells and systems for telecom, solar, UPS, AGV and traction applications. 8 production bases, 70 million kVAh annual capacity, ISO 9001 and ISO 14001 certified.

    Related CHISEN Buyer Guides

  • 12V 50Ah Motorcycle Battery: Choosing Between the 6-EVF-50, 6-DMF-45 and 6-DMF-52 (2026)

    12V 50Ah Motorcycle Battery: Choosing Between the 6-EVF-50, 6-DMF-45 and 6-DMF-52 (2026)

    Answer First

    A 12V 50Ah motorcycle battery in the CHISEN range is not one product but two honest answers to two different questions: the 6-EVF-50, a sealed 50 Ah AGM block at 230 × 140 × 180 mm and 15.25 ± 0.2 kg whose published applications are sightseeing vehicles, golf carts, electric forklifts, floor scrubbers, AGV platforms and electric boats, and the 6-DMF-52, a 52 Ah VRLA block at 224 × 135 × 175 mm and 13.7 ± 0.2 kg that the manufacturer publishes for electric tricycles, electric motorcycles and electric mopeds, with the 6-DMF-45 at 45 Ah as the lighter option. Both charge at 13.5 V float and 14.1 V equalisation across six cells, both are rated at the three-hour rate, and this guide sets out the published figures for all four 12V cells in this class so the pack you fit to a frame can be defended at the goods-in dock.

    Key Takeaways

    • The published motorcycle and moped duty belongs to the 6-DMF series: 6-DMF-45 at 45 Ah, 6-DMF-52 at 52 Ah, 6-DMF-38 at 38 Ah. The exactly-50 Ah 6-EVF-50 is published for mobility and industrial applications, not for motorcycles.
    • The 6-EVF-50 gives 12 V × 50 Ah = 600 Wh at 15.25 ± 0.2 kg, which is 600 Wh ÷ 15.25 kg = 39.3 Wh/kg; the 6-DMF-52 gives 624 Wh ÷ 13.7 kg = 45.5 Wh/kg and the 6-DMF-45 gives 540 Wh ÷ 12.3 kg = 43.9 Wh/kg.
    • Weight is the decision that matters on a two-wheeler: a 48 V pack of four 6-EVF-50 cells is 4 × 15.25 kg = 61.0 kg, against 4 × 13.7 kg = 54.8 kg for the 6-DMF-52 and 4 × 12.3 kg = 49.2 kg for the 6-DMF-45.
    • Float 13.5 V and equalisation 14.1 V for the block — 2.25 V and 2.35 V per cell — are the setpoints to fix in writing; the published charge currents are 10.0 A, 10.4 A, 9.0 A and 7.6 A for the four cells.
    • Capacity is published at the C3 rate down to a cut-off of 1.75 V per cell, cycle life at 350–600 cycles to 50–80 % depth of discharge and design life at 2–5 years; a quotation that gives Ah without the rate basis is incomplete.

    §1 — 12V 50Ah Motorcycle Battery Specifications

    The table below reproduces the published specification for the 6-EVF-50 and the three 6-DMF cells that sit around it in the 12V VRLA range. Every cell figure is taken from the manufacturer model page; the pack figures are derived and shown with their formulas.

    Specification6-EVF-506-DMF-456-DMF-526-DMF-38Source
    Nominal voltage12 V12 V12 V12 VModel page
    Rated capacity50 Ah45 Ah52 Ah38 AhModel page
    Discharge rate basisC3 (3 h)C3 (3 h)C3 (3 h)C3 (3 h)Model page
    Dimensions L × W × H230 × 140 × 180 mm224 × 121 × 175 mm224 × 135 × 175 mm224 × 106 × 175 mmModel page
    Weight15.25 ± 0.2 kg12.3 ± 0.2 kg13.7 ± 0.2 kg10.45 ± 0.2 kgModel page
    Terminalφ11.8-M6φ11.8-M5φ11.8-M6φ9.8-M5Model page
    Maximum charge current10.0 A9.0 A10.4 A7.6 AModel page
    Float charge voltage13.5 V13.5 V13.5 V13.5 VModel page
    Equalisation voltage14.1 V14.1 V14.1 V14.1 VModel page
    Cycle life (DoD 50–80 %)350–600 cycles350–600 cycles350–600 cycles350–600 cyclesModel page
    Cut-off voltage1.75 V/cell1.75 V/cell1.75 V/cell1.75 V/cellModel page
    Self-discharge≤ 3 %/month at 25 °C≤ 3 %/month at 25 °C≤ 3 %/month at 25 °C≤ 3 %/month at 25 °CModel page
    Working temperature−15 °C to 50 °C−15 °C to 50 °C−15 °C to 50 °C−15 °C to 50 °CModel page
    Design life2–5 years2–5 years2–5 years2–5 yearsModel page
    Published applicationsSightseeing vehicles, golf carts, electric forklifts and stackers, floor scrubbers, AGV platforms, electric boatsElectric tricycles, electric motorcycles, electric mopeds, sanitation trucks, sightseeing vehiclesElectric tricycles, electric motorcycles, electric mopedsElectric tricycles, electric motorcycles, electric mopedsModel page
    Energy per cell12 V × 50 Ah = 600 Wh12 V × 45 Ah = 540 Wh12 V × 52 Ah = 624 Wh12 V × 38 Ah = 456 WhArithmetic
    Specific energy600 Wh ÷ 15.25 kg = 39.3 Wh/kg540 Wh ÷ 12.3 kg = 43.9 Wh/kg624 Wh ÷ 13.7 kg = 45.5 Wh/kg456 Wh ÷ 10.45 kg = 43.6 Wh/kgArithmetic
    Series build published4 = 48 V, 5–6 = 60–72 V, 8 = 96 V4 = 48 V4 = 48 V4 = 48 VModel page

    One ordering note belongs here rather than in the footer: several of these model pages also list alternative weight variants in a horizontal comparison table, because the same capacity can be built in a different case or terminal configuration. Whichever variant you specify, have it confirmed on the order acknowledgement before the container is sealed, because a one-kilogram difference per cell becomes four kilograms per four-cell pack and a different terminal means a different lead.

    §2 — The Pain

    Three failures account for almost every 12V 50Ah motorcycle battery complaint that reaches a distributor’s help desk in Hamburg, Durban or Mombasa.

    The first is the label. A carton marked “50 Ah 12V motorcycle battery” tells you nothing about the case, the terminals, the rate basis of the capacity or the charge setpoints. Two suppliers can both print “12V 50Ah” and deliver two different products — one a 50 Ah AGM block weighing 15.25 kg, the other a 52 Ah plate cell weighing 13.7 kg with a completely different case. A buyer who orders on the label alone receives a battery that may not fit the frame bracket, and the mismatch is discovered after the cartons are open.

    The second is the charger. A 12 V block contains six cells in series, so the published float voltage of 13.5 V is 2.25 V per cell and the published equalisation voltage of 14.1 V is 2.35 V per cell. Controllers left on a generic lead-acid default of 14.4 V over-charge the pack; controllers that never enter equalisation at all under-charge it and build sulphate within the first year. Neither shows up on the invoice.

    The third is weight and mounting. A 48 V pack of four 6-EVF-50 cells weighs 4 × 15.25 kg = 61.0 kg. On a passenger electric motorcycle or a cargo tricycle that mass sits directly in the centre of gravity and it changes how the vehicle handles and how far it can travel. The 6-DMF-52 gives the same 48 V string at 4 × 13.7 kg = 54.8 kg, a saving of 6.2 kg per pack, and the 6-DMF-45 at 4 × 12.3 kg = 49.2 kg saves 11.8 kg. On a fleet of ten vehicles that is 62 kg and 118 kg of payload recovered.

    Underneath all three sits a sourcing problem. Buyers in Lagos, Chennai, Cairo and Jakarta regularly receive a quotation listing “12V 50Ah motorcycle battery, heavy duty, competitive price” with no datasheet reference, which makes the order impossible to compare between suppliers and impossible to re-order next season.

    §3 — The Choice

    Choosing between these four cells is a trade between three published quantities: the case footprint, the weight per amp-hour, and the charge current your charger has to deliver. The table below sets the four cells against each other and then shows the packs they build.

    Cell comparison6-EVF-506-DMF-456-DMF-526-DMF-38Source
    Rated capacity50 Ah45 Ah52 Ah38 AhModel page
    Weight per cell15.25 kg12.3 kg13.7 kg10.45 kgModel page
    Energy per cell600 Wh540 Wh624 Wh456 WhArithmetic
    Specific energy39.3 Wh/kg43.9 Wh/kg45.5 Wh/kg43.6 Wh/kgArithmetic
    Charge current per cell10.0 A9.0 A10.4 A7.6 AModel page
    Charger for a 4-cell 48 V pack4 × 10.0 A = 40.0 A4 × 9.0 A = 36.0 A4 × 10.4 A = 41.6 A4 × 7.6 A = 30.4 AArithmetic
    48 V pack energy48 V × 50 Ah = 2,400 Wh48 V × 45 Ah = 2,160 Wh48 V × 52 Ah = 2,496 Wh48 V × 38 Ah = 1,824 WhArithmetic
    48 V pack weight4 × 15.25 kg = 61.0 kg4 × 12.3 kg = 49.2 kg4 × 13.7 kg = 54.8 kg4 × 10.45 kg = 41.8 kgArithmetic
    Recharge window at the published current50 Ah ÷ 10.0 A = 5.0 h45 Ah ÷ 9.0 A = 5.0 h52 Ah ÷ 10.4 A = 5.0 h38 Ah ÷ 7.6 A = 5.0 hArithmetic

    Read the table as four answers to four different questions.

    If the vehicle on your order sheet is a motorcycle, a moped or a tricycle, the 6-DMF-52 is the cell the manufacturer publishes for that duty: 52 Ah, 13.7 kg, 10.4 A charge current, with the full specification on the 6-DMF-52 model page. It also carries the best specific energy of the four at 45.5 Wh/kg, which means the lightest pack per unit of energy.

    If the frame has a hard weight limit and the range target can come down, the 6-DMF-45 gives 540 Wh at 12.3 kg, or 43.9 Wh/kg, and the 48 V pack drops to 49.2 kg with a 36.0 A charger. The complete 6-DMF and 6-DZF range sits on the CHISEN 12V VRLA product index.

    If the application is instead a golf cart, a scrubber, an AGV platform or a sightseeing vehicle, the 6-EVF-50 is the cell published for that duty, and it is the exact 50 Ah the search term implies. Its published 39.3 Wh/kg is the lowest of the four, which is the price of a 230 × 140 × 180 mm footprint with a larger case volume.

    If the duty is a light tricycle or a smaller platform where every kilogram counts, the 6-DMF-38 gives 456 Wh at 10.45 kg, 43.6 Wh/kg, and a 48 V pack of 41.8 kg with a 30.4 A charger — the smallest charger requirement in the set.

    For the exactly-50 Ah size with no model code attached, the 6-EVF-50 model page carries the published figure set: 50 Ah at C3, 230 × 140 × 180 mm, 15.25 ± 0.2 kg, float 13.5 V, equalisation 14.1 V, 10.0 A maximum charge current and 350–600 cycles at 50–80 % depth of discharge.

    §4 — The Framework

    Seven checks turn a vague enquiry into an order a factory can fill correctly.

    1. Demand the published figure set, not the label. Ask for capacity with its rate basis, dimensions in millimetres, weight with tolerance, terminal type, float and equalisation voltage, maximum charge current, cycle rating and cut-off voltage. A supplier that answers all nine is not guessing. A supplier that answers with “50 Ah heavy duty” is.

    2. Match the cell to the published duty. The 6-DMF series is published for electric tricycles, motorcycles and mopeds; the 6-EVF-50 is published for sightseeing vehicles, golf carts, forklifts, scrubbers, AGV platforms and boats. Ask the supplier to state which published application list the cell sits on. If the answer does not appear on the model page, the cell is being described rather than specified.

    3. Fix the charge setpoints in writing. 13.5 V float and 14.1 V equalisation for the block; 2.25 V and 2.35 V per cell once you do the arithmetic. Confirm the controller can be configured to both and confirm the equalisation period. If the answer is “it is automatic”, ask which controller models are tested.

    4. Size the charger from the published charge current. The 6-DMF-52 accepts 10.4 A, so a 48 V pack of four needs 4 × 10.4 A = 41.6 A. A smaller charger stretches the recharge window and leaves the pack in a partially discharged state, which is the condition that damages plates fastest.

    5. Check the case, the terminal and the lead length in the frame. 230 × 140 × 180 mm, 224 × 135 × 175 mm, 224 × 121 × 175 mm and 224 × 106 × 175 mm are four different mouldings. The terminal changes with them, from φ11.8-M6 through φ11.8-M5 to φ9.8-M5, so the connector and the cable gauge change too. Measure the bracket before the order, not after the arrival.

    6. Verify the temperature envelope. The published working range is −15 °C to 50 °C, capacity is quoted at 25 °C and self-discharge is ≤ 3 % per month at 25 °C. A fleet parked outside through a Hamburg winter or a Santos summer does not see 25 °C for most of its life; ask what capacity remains at the extremes.

    7. Agree the acceptance test. For shipments into Santos, Jebel Ali, Lagos or Port Said, specify what happens on arrival: a sample capacity check at the C3 rate, a float voltage check across the block, and the rule that a failing sample is settled by re-inspection at an agreed laboratory rather than by argument.

    §5 — The Trust

    These cells are built on a VRLA line inside a manufacturer operating 8 production bases with an annual capacity of 70 million kVAh, under a certified quality management system with ISO 9001 and ISO 14001 certification, with CE, UL and IEC conformity for the markets each cell ships into, and with GB/T 32620.1-2016 and GB/T 32620.2-2016 cited as the VRLA standards on the product pages. Every figure in this article comes from an individual model page rather than from a catalogue summary.

    Two points deserve emphasis for a buyer who is being asked to pay for assurance. First, a certificate covers a system, a scope and a date — ISO 9001 certifies that the quality management system is documented and that corrective action happens; it does not certify that one cell holds 52 Ah. That is what the published capacity, the type test and the acceptance test are for. Ask for the certificate number, the scope statement, the registered address and the validity dates, and then check the cell on its own merits.

    Second, the difference between a published specification and a marketing line is the whole value of this exercise. A supplier who quotes “12V 50Ah motorcycle battery, top grade” is telling you nothing. A supplier who quotes “6-DMF-52, 52 Ah at C3, 224 × 135 × 175 mm, 13.7 ± 0.2 kg, float 13.5 V, equalisation 14.1 V, 10.4 A maximum charge current” is telling you everything you need to engineer the pack, write the charger setting and defend the claim at the goods-in dock.

    For importers who buy through a distributor rather than direct, ask the distributor for the manufacturer’s model page URL and the batch reference. Both can be checked before the container is opened, and both remove the single largest source of dispute in this category.

    §6 — FAQ

    Q1. Which 12V 50Ah battery does CHISEN publish for motorcycles? The manufacturer publishes the electric tricycle, electric motorcycle and electric moped duty on the 6-DMF series — the 6-DMF-45, 6-DMF-52 and 6-DMF-38. The exactly-50 Ah cell is the 6-EVF-50, and its published application list covers sightseeing vehicles, golf carts, electric forklifts and stackers, floor scrubbers, AGV platforms and electric boats rather than motorcycles.

    Q2. What is the difference between 6-EVF-50 and 6-DMF-52? Both are 12V VRLA blocks in the same capacity class. The 6-EVF-50 is published at 230 × 140 × 180 mm and 15.25 ± 0.2 kg, the 6-DMF-52 at 224 × 135 × 175 mm and 13.7 ± 0.2 kg, and the 6-DMF-52 carries the higher specific energy at 45.5 Wh/kg against 39.3 Wh/kg. The terminal dimension stays at φ11.8-M6 on both, but they are different mouldings, so check the lead length and the retaining hardware.

    Q3. Can I put two 12V 50Ah batteries on a 24V motorcycle? In series, yes: two 12 V blocks give 24 V at 50 Ah, which is 24 V × 50 Ah = 1,200 Wh, and the pair weighs 2 × 15.25 kg = 30.5 kg for the 6-EVF-50 or 2 × 13.7 kg = 27.4 kg for the 6-DMF-52. The charger must then be a 24 V unit set to 13.5 V float and 14.1 V equalisation for the whole string. In parallel the voltage stays at 12 V and the capacity doubles, which is a different duty.

    Q4. What charger do I need for a 48 V pack of four 12V 50Ah batteries? A 48 V charger with a 40.0 A output for the 6-EVF-50, because the published maximum charge current is 10.0 A per cell and 4 × 10.0 A = 40.0 A. Set float at 13.5 V and equalisation at 14.1 V for the string, which is 2.25 V and 2.35 V per cell.

    Q5. How long will a 12V 50Ah motorcycle battery last? The published design life is 2–5 years in float standby and the published cycle rating is 350–600 cycles at 50–80 % depth of discharge. For a vehicle on daily use the binding factor is usually the number of deep cycles rather than the calendar, and a motorcycle that is recharged every evening at the service point will consume cycles faster than a standby installation.

    Q6. Does the 50 Ah rating hold all day on a motorcycle? No. Capacity is published at the C3 rate down to a cut-off of 1.75 V per cell. On a longer, five-hour discharge the usable figure is lower and on a two-hour discharge it is higher. Any quotation that gives 50 Ah without the rate basis is incomplete, and sizing a range target on the headline number is the most common way a two-wheeler comes up short.

    Q7. What terminal and lead do these cells use? The 6-EVF-50 and 6-DMF-52 use φ11.8-M6 terminals, the 6-DMF-45 uses φ11.8-M5 and the 6-DMF-38 uses φ9.8-M5. The connector, the cable gauge and the crimp all follow the terminal, so specify the terminal in the order line and have the lead length confirmed on the packing list.

    Q8. Can I substitute the 6-DMF-52 for the 6-EVF-50 in an existing 48 V pack? Usually yes, and it is usually an improvement on weight: 48 V × 52 Ah = 2,496 Wh at 4 × 13.7 kg = 54.8 kg against 48 V × 50 Ah = 2,400 Wh at 4 × 15.25 kg = 61.0 kg. Before you do, confirm the case footprint fits the tray — 224 × 135 × 175 mm against 230 × 140 × 180 mm — and confirm the charger can deliver 4 × 10.4 A = 41.6 A.

    Q9. What should be on the purchase order for a 12V 50Ah motorcycle battery? The model code and the case and weight variant, the float and equalisation voltages, the maximum charge current, the capacity and its rate basis, the cycle rating and depth of discharge, the terminal type and lead length, the batch reference, the test certificate and the acceptance procedure on arrival. If the order ships to a port such as Rotterdam, Santos or Mombasa, name the agreed laboratory for a failing-sample inspection.

    Q10. Is there a lithium alternative worth considering for the same duty? Lithium packs change the weight arithmetic entirely and remove the charge-setpoint question, because the management electronics hold the profile. They also change the quotation structure, the certification file and the shipping classification. Compare them on published weight, published warranty terms and delivered cost per cycle over the intended service life rather than on price per unit.

    Expert Summary

    A 12V 50Ah motorcycle battery is a specification exercise, not a product search. The published figures behind the choice are: 50 Ah at C3, 230 × 140 × 180 mm, 15.25 ± 0.2 kg, float 13.5 V, equalisation 14.1 V, 10.0 A maximum charge current, 350–600 cycles at 50–80 % depth of discharge and 2–5 years design life for the 6-EVF-50; and 52 Ah at C3, 224 × 135 × 175 mm, 13.7 ± 0.2 kg, 10.4 A and the same 13.5 V / 14.1 V setpoints for the 6-DMF-52, which is the cell published for electric motorcycles and mopeds.

    The commercial value of specifying precisely is larger than the price difference between the cells. A quotation built on a published figure set can be compared across three suppliers in ten minutes and defended at the goods-in dock. A quotation built on a label cannot be compared at all, and the difference shows up three months later as a warranty claim.

    Two figures deserve a final emphasis for buyers working outside Europe. First, the 40.0 A charger requirement for a 48 V pack of four cells is set by the published maximum charge current, not by marketing; a smaller charger stretches the recharge window and leaves the pack half-discharged, which is exactly the condition that sulphates a plate. Second, the 6.2 kg per pack saved by the 6-DMF-52 over the 6-EVF-50 is payload recovered on every vehicle, and on a ten-vehicle fleet it is 62 kg — a number that belongs in the same conversation as the unit price.

    For importers into markets served from Rotterdam, Jebel Ali, Santos, Lagos or Chennai, the sequence that works is simple: fix the published specification first, then let suppliers compete on it. The one-page figure set in §1 is enough to run that process.

    Contact CHISEN

    Send the vehicle type and duty, the required capacity, the frame or tray dimensions you need to fit and the quantity to the CHISEN export desk, and you will receive a quotation against the published specification, the datasheet and the current lead time.

    • Email: jack@chisen.cn or sales@chisen.cn
    • WhatsApp: +86 131 6622 6999
    • 6-EVF-50 model page: https://www.chisen.cn/en/6-EVF-50/12V50Ah.html
    • 6-DMF-52 model page: https://www.chisen.cn/en/6-DMF-52/12V52Ah.html
    • 12V VRLA product index: https://www.chisen.cn/en/Leadacidbattery/DZF-DMF.html

    Related reading on the CHISEN knowledge centre: 12V VRLA selection guidance, deep-cycle charge setpoints, and pack-sizing method for electric motorcycle, tricycle and mobility applications.

    CHISEN Battery — lead-acid cells and systems for telecom, solar, UPS, AGV and traction applications. 8 production bases, 70 million kVAh annual capacity, ISO 9001 and ISO 14001 certified.

    Related CHISEN Buyer Guides

  • Forklift Battery 48V: AGM Pack Sizing for Electric Forklifts (2026)

    Forklift Battery 48V: AGM Pack Sizing for Electric Forklifts (2026)

    Answer First

    A forklift battery 48V pack is four 12V traction batteries connected in series, and every commercial decision about it follows from that single fact: energy, weight, charger size and charge time are all set by which 6-EVF unit you repeat four times. The CHISEN 6-EVF line publishes six capacities for that build — 60 Ah, 80 Ah, 100 Ah, 120 Ah, 135 Ah and 150 Ah at the 3-hour rate to a 1.75 V/cell cut-off — and each publishes its own dimensions, weight and maximum charge current. A 48V pack built from four 6-EVF-150 units delivers 48 V × 150 Ah = 7,200 Wh and weighs 4 × 48.5 kg = 194.0 kg; the same 48V pack built from four 6-EVF-60 units delivers 2,880 Wh and weighs 4 × 18.8 kg = 75.2 kg. Float across the string is 4 × 13.5 V = 54.0 V and equalisation is 4 × 14.1 V = 56.4 V. This guide sizes those packs from published data only, so the truck class, the shift pattern and the charger can be fixed before a quotation is requested.

    Key Takeaways

    • A 48V forklift pack is 4 × 12V in series: 48 V × Ah equals the pack energy, so four 6-EVF-150 units give 48 V × 150 Ah = 7,200 Wh.
    • Published weights make the pack heavy: 4 × 18.8 kg = 75.2 kg for the 60 Ah build, rising to 4 × 48.5 kg = 194.0 kg for the 150 Ah build — a 118.8 kg difference that changes the counterweight balance and the floor loading.
    • The 6-EVF range is rated at the 3-hour rate to a 1.75 V/cell cut-off, so 60 Ah means 60 Ah at C3, not at C10.
    • Every published maximum charge current is 0.2 C: 12.0 A for the 6-EVF-60, 20.0 A for the 6-EVF-100, 24.0 A for the 6-EVF-120, 27.0 A for the 6-EVF-135 and 30.0 A for the 6-EVF-150. In a series pack the string charges at the cell rating, so the 48V charger is a 48V/30 A unit, not 120 A.
    • Float is 13.5 V and equalisation 14.1 V for a 12V unit, which is 54.0 V and 56.4 V across a 48V pack and 2.25 V per cell in float.
    • Published cycle life is 350-600 cycles at 50-80% depth of discharge, and float design life is 2-5 years — these are separate numbers and a buyer quoting only the cycle figure is quoting the wrong one for a standby duty.
    • Working range is −15 °C to 50 °C and storage −20 °C to 45 °C, which puts a container-side warehouse in Rotterdam or Durban inside the published window but a dock in Chennai in summer close to the upper limit.

    §1 — Forklift Battery 48V Specifications

    All values below are read from the manufacturer model pages for each 6-EVF unit, or derived from them by arithmetic. The 6-EVF range is the AGM valve-regulated traction series: high-strength AGM grids, cadmium-free and mercury-free plates, and the published compliance set is GB/T 32620.1-2016 and GB/T 32620.2-2016 for electric road vehicle lead-acid batteries, with JB/T 2599 referenced, alongside CE, RoHS, REACH, MSDS and IMDG sea freight documentation.

    Specification6-EVF-606-EVF-806-EVF-1006-EVF-1206-EVF-1356-EVF-150Source
    Nominal voltage12V12V12V12V12V12VModel page
    Rated capacity at C3 (1.75 V/cell)60 Ah80 Ah100 Ah120 Ah135 Ah150 AhModel page
    Dimensions L × W × H258 × 170 × 160 mm259 × 170 × 218 mm330 × 170 × 218 mm407 × 170 × 240 mm338 × 172 × 280 mm483 × 170 × 240 mmModel page
    Total height with terminals160 mm218 mm218 mm240 mm280 mm240 mmModel page
    Weight18.8 ± 0.2 kg25.7 kg31.5 ± 0.2 kg40 ± 0.2 kg45 ± 0.2 kg48.5 kgModel page
    Terminalφ14-M6φ16-M6φ20-M8φ20-M8φ20-M8φ20-M8Model page
    Maximum charge current12.0 Anot published20.0 A24.0 A27.0 A30.0 AModel page
    Charge current as a fraction of capacity12.0 A ÷ 60 Ah = 0.2 Cnot published20.0 A ÷ 100 Ah = 0.2 C24.0 A ÷ 120 Ah = 0.2 C27.0 A ÷ 135 Ah = 0.2 C30.0 A ÷ 150 Ah = 0.2 CArithmetic
    Float charge voltage13.5 V13.5 V13.5 V13.5 V13.5 V13.5 VModel page
    Equalisation charge voltage14.1 V14.1 V14.1 V14.1 V14.1 V14.1 VModel page
    Float voltage per cell13.5 V ÷ 6 = 2.25 V2.25 V2.25 V2.25 V2.25 V2.25 VArithmetic
    Float design life2-5 years2-5 years2-5 years2-5 years2-5 years2-5 yearsModel page
    Cycle life at 50-80% DoD350-600 cycles350-600 cycles350-600 cycles350-600 cycles350-600 cycles350-600 cyclesModel page
    Working temperature−15 °C to 50 °C−15 °C to 50 °C−15 °C to 50 °C−15 °C to 50 °C−15 °C to 50 °C−15 °C to 50 °CModel page
    Storage temperature−20 °C to 45 °C−20 °C to 45 °C−20 °C to 45 °C−20 °C to 45 °C−20 °C to 45 °C−20 °C to 45 °CModel page
    Self-discharge≤ 3% per month at 25 °C≤ 3% per month at 25 °C≤ 3% per month at 25 °C≤ 3% per month at 25 °C≤ 3% per month at 25 °C≤ 3% per month at 25 °CModel page
    TechnologyVRLA AGMVRLA AGMVRLA AGMVRLA AGMVRLA AGMVRLA AGMModel page
    Energy per 12V unit12V × 60 Ah = 720 Wh12V × 80 Ah = 960 Wh12V × 100 Ah = 1,200 Wh12V × 120 Ah = 1,440 Wh12V × 135 Ah = 1,620 Wh12V × 150 Ah = 1,800 WhArithmetic

    Two details in that table change how a 48V quote should be read.

    The first is the capacity rate. The 6-EVF range publishes capacity at the 3-hour rate to a 1.75 V/cell cut-off, not at the 10-hour rate. That is correct practice for a traction duty, where the truck draws close to its rated current during a lift, but it means a “120 Ah” unit on this list is not directly comparable to a “120 Ah” VRLA quoted at C10 for standby duty. Ask for the rate and the cut-off on the order line, and compare like with like.

    The second is the charge current. Every published value is exactly 0.2 C, which tells the buyer the charger’s amperage before any arithmetic: a 48V pack from four 6-EVF-150 units takes a 48V/30 A charger, and a 48V pack from four 6-EVF-100 units takes a 48V/20 A charger. Because the four units are in series, current passes through all of them, so the pack rating is the cell rating — the pack current is not the sum of the four.

    §2 — The Pain

    Three specification failures account for most of the unusable 48V forklift quotations a buyer receives.

    The first is a 48V pack described only by voltage and amp-hours. “48V 150Ah forklift battery” describes an energy quantity and nothing about the physical pack. The four 6-EVF-150 units that hold 7,200 Wh occupy 4 × 483 mm of length in the truck bay, weigh 194.0 kg and split across two rows. The same energy in a different case format — six 8V 150 Ah units — weighs 6 × 34.8 kg = 208.8 kg and occupies 6 × 260 mm. A buyer who specifies only volts and amp-hours cannot control the bay envelope, the floor loading or the counterweight balance, and by the time the pallet arrives the frame will not take it.

    The second is a charger sized on the sum of the battery ratings. Four units rated 30 A each do not accept 120 A. A 120 A charger on a 48V pack charges each unit at 120 A, which is 0.8 C on a 150 Ah cell — roughly four times the published maximum. The damage is not immediate; it is elevated temperature on charge, electrolyte loss in the AGM separators and a shortened service life across the whole pack. The correct charger is 48V at the published cell rating.

    The third is cycle life quoted where float life is needed. The 6-EVF range publishes two different lifetimes, and they are not interchangeable. The float design life is 2-5 years. The cycle life is 350-600 cycles at 50-80% depth of discharge, and the same model pages also carry a 400-650 cycle figure in their detailed table, which is why the two numbers circulate in parallel in the market. A warehouse running one charge cycle a day is buying cycles; a fleet vehicle parked at the dock for four hours between shifts is buying float standby capability, and the reserve margin for that duty comes from the 2-5 year float design life and from sizing the pack against the load, not from the cycle figure.

    There is a fourth, quieter problem. A forklift battery spends its life in a bay that is either open to the dock or in a charging alcove with poor ventilation, and the published working range of −15 °C to 50 °C is a wide band. A pack charged at 50 °C in a closed alcove in Chennai or Jebel Ali is outside the comfortable middle of that band, and the published guidance is explicit that charging should be carried out on a cooled battery and not in hot sun or an enclosed high-temperature space. That is a charger siting decision, and it belongs in the enquiry.

    §3 — The Choice

    The table below is the actual selection: the same 48V pack, built from the four published 6-EVF units. Every weight and energy figure is derived from the unit values in §1.

    48V pack build4 × 6-EVF-604 × 6-EVF-804 × 6-EVF-1004 × 6-EVF-1204 × 6-EVF-1354 × 6-EVF-150Source
    Units in series4 × 12V = 48V4 × 12V = 48V4 × 12V = 48V4 × 12V = 48V4 × 12V = 48V4 × 12V = 48VArithmetic
    Pack energy48 V × 60 Ah = 2,880 Wh48 V × 80 Ah = 3,840 Wh48 V × 100 Ah = 4,800 Wh48 V × 120 Ah = 5,760 Wh48 V × 135 Ah = 6,480 Wh48 V × 150 Ah = 7,200 WhArithmetic
    Pack weight4 × 18.8 kg = 75.2 kg4 × 25.7 kg = 102.8 kg4 × 31.5 kg = 126.0 kg4 × 40 kg = 160.0 kg4 × 45 kg = 180.0 kg4 × 48.5 kg = 194.0 kgArithmetic
    Specific energy2,880 Wh ÷ 75.2 kg = 38.3 Wh/kg3,840 Wh ÷ 102.8 kg = 37.4 Wh/kg4,800 Wh ÷ 126.0 kg = 38.1 Wh/kg5,760 Wh ÷ 160.0 kg = 36.0 Wh/kg6,480 Wh ÷ 180.0 kg = 36.0 Wh/kg7,200 Wh ÷ 194.0 kg = 37.1 Wh/kgArithmetic
    Longest unit in the pack258 mm259 mm330 mm407 mm338 mm483 mmModel page
    Charger rating48V / 12 A48V / 16 A or below (0.2 C pattern)48V / 20 A48V / 24 A48V / 27 A48V / 30 AArithmetic
    Float set point4 × 13.5 V = 54.0 V54.0 V54.0 V54.0 V54.0 V54.0 VArithmetic
    Equalisation set point4 × 14.1 V = 56.4 V56.4 V56.4 V56.4 V56.4 V56.4 VArithmetic
    Charge acceptance80% charge in ≤ 4 hours80% charge in ≤ 4 hours80% charge in ≤ 4 hours80% charge in ≤ 4 hours80% charge in ≤ 4 hours80% charge in ≤ 4 hoursModel page
    Published cycle life350-600 cycles at 50-80% DoD350-600 cycles at 50-80% DoD350-600 cycles at 50-80% DoD350-600 cycles at 50-80% DoD350-600 cycles at 50-80% DoD350-600 cycles at 50-80% DoDModel page
    Pack documentation6-EVF-60 model page6-EVF-80 model page6-EVF-100 model page6-EVF-120 model page6-EVF-135 model page6-EVF-150 model pageModel page

    Read across the rows and the pattern is clear. The specific energy sits in a narrow band of 36.0 to 38.3 Wh/kg for every build, so a bigger pack is heavier in proportion to what it stores rather than being efficiently or inefficiently designed. The 4 × 6-EVF-60 build is the lightest per unit of energy at 38.3 Wh/kg; the 4 × 6-EVF-120 build carries the same 36.0 Wh/kg as the 135 Ah build, because the 120 Ah case is long at 407 mm and the 135 Ah case is tall at 280 mm with a smaller footprint of 338 × 172 mm. If the bay is short and narrow, the 6-EVF-135 may be the only unit that physically fits, and that constraint should override the energy comparison.

    The 6-EVF-100 build at 126.0 kg and 4,800 Wh is the common middle choice for 1 to 3 tonne trucks working a single shift, and its 20 A charger is also the most widely deployed 48V charger size. The 6-EVF-150 build at 194.0 kg is a two-shift or high-utilisation pack, and it is the heaviest item that a 1 tonne counterbalance truck is designed to carry as battery — which is why the truck’s own lift and counterweight calculation has to be done with the published 194.0 kg figure and not with a generic “150 Ah battery” weight.

    For a warehouse in Rotterdam or a distribution centre in Durban running single-shift operation, the 4 × 6-EVF-100 build at 4,800 Wh and 126.0 kg is usually the correct starting point; for a two-shift operation in Chennai or São Paulo with a fast turn-around charge window, the 4 × 6-EVF-150 build with a 48V/30 A charger keeps the published ≤ 4 hour charge acceptance intact. The wider AGM range behind these units is indexed on the CHISEN AGM battery page.

    §4 — The Framework

    Seven checks turn a 48V forklift battery enquiry into a pack that fits the bay, the charger and the duty cycle.

    1. State the unit model, not just the pack voltage. Write “4 × 6-EVF-100 in series” rather than “48V 100Ah forklift battery”. The unit code determines the case dimensions, the weight, the terminal type and the published charge current, and none of those can be derived from the pack label.

    2. Confirm the capacity rate and cut-off. The published rating is C3 to 1.75 V/cell. A second table on the same pages quotes 400-650 cycles against the 350-600 cycle figure, so ask which figure is being quoted and on which basis before comparing two suppliers.

    3. Derive the charger from the cell, not the pack. The pack current equals the unit current because the units are in series. 48V/20 A for the 6-EVF-100 build, 48V/30 A for the 6-EVF-150 build.

    4. Check the physical envelope against the truck bay. Longest unit per build runs from 258 mm to 483 mm, and the 6-EVF-135 is 338 × 172 × 280 mm against the 6-EVF-150 at 483 × 170 × 240 mm. Measure the bay, not the catalogue.

    5. Do the weight arithmetic against the truck. 75.2 kg, 102.8 kg, 126.0 kg, 160.0 kg, 180.0 kg and 194.0 kg for the six builds. The 118.8 kg spread between the smallest and the largest pack is the difference between a truck that stays within its rated envelope and one that loses stability with a raised load.

    6. Write the set points to the volt. 54.0 V float and 56.4 V equalisation across the 48V pack, which is 13.5 V and 14.1 V per 12V unit and 2.25 V per cell in float. Put them in the charger configuration table and in the maintenance schedule.

    7. Plan the charging environment. The published working range is −15 °C to 50 °C and storage is −20 °C to 45 °C. Charge on a cooled battery, out of direct sun, in a ventilated alcove, and agree a named laboratory for the arrival capacity test on shipments into Santos, Jebel Ali, Lagos or Port Said.

    §5 — The Trust

    The 6-EVF range is produced inside a manufacturer that operates 8 production bases with an annual capacity of 70 million kVAh, under a quality management system certified to ISO 9001 with ISO 14001 covering the environmental system, and with CE, RoHS, REACH, MSDS and IMDG documentation for the destination market. The product pages for these units carry the full physical data and the GB/T 32620.1-2016 and GB/T 32620.2-2016 compliance references for lead-acid batteries for electric road vehicles, with JB/T 2599 referenced, and the wider AGM range is indexed on the CHISEN AGM battery page.

    Two things deserve emphasis before a fleet purchase is committed.

    First, the standards quoted here are checkable, and they are more useful than a generic CE mark. GB/T 32620.1-2016 and GB/T 32620.2-2016 are the Chinese national standards for lead-acid batteries used in electric road vehicles, and they set the technical conditions and product-type definitions a traction battery is built against. Ask for the test report that references them, with the report number, the unit model and the date. A supplier who publishes a range, a certificate index and a per-model datasheet is answering a different question from one who publishes only a product listing.

    Second, a float design life of 2-5 years and a cycle life of 350-600 cycles describe two different services, and a fleet’s real replacement interval is whichever is reached first under the actual duty. A truck that charges overnight and works one shift consumes float standby capability; a truck on two shifts with an opportunity charge consumes cycles. Write the duty pattern into the enquiry and ask the supplier which figure they will stand behind for it, because that is the number a fleet manager will be held to.

    A third point is about the arrival of the goods. Published data is published data, but a delivered pack is also a physical assembly: four units of the same model and batch, matched at the terminals, with a float voltage check across all four and a capacity check on one unit from the pack before it goes into service. For shipments into Santos, Jebel Ali, Lagos or Port Said, agree that inspection and the laboratory that will repeat it before the truck goes onto the floor.

    §6 — FAQ

    Q1. What does a 48V forklift battery consist of? Four 12V traction batteries connected in series. Four 6-EVF-150 units give 48 V × 150 Ah = 7,200 Wh; four 6-EVF-100 units give 48 V × 100 Ah = 4,800 Wh; four 6-EVF-60 units give 48 V × 60 Ah = 2,880 Wh. Because the four units are in series, the pack voltage is 48 V and the pack amp-hour rating equals the rating of one unit, not the sum of four.

    Q2. What size charger does a 48V forklift battery need? One rated at the unit’s published maximum charge current, because in a series pack the current passes through every unit. The published maximum charge current is 0.2 C on every unit in the range: 12.0 A for the 6-EVF-60, 20.0 A for the 6-EVF-100, 24.0 A for the 6-EVF-120, 27.0 A for the 6-EVF-135 and 30.0 A for the 6-EVF-150. A 48V/30 A charger therefore suits a pack of four 6-EVF-150 units. A charger rated at the sum of the four unit ratings would deliver four times the published maximum to every unit.

    Q3. How much does a 48V forklift battery weigh? It depends entirely on the unit repeated four times: 4 × 18.8 kg = 75.2 kg for the 6-EVF-60 build, 4 × 25.7 kg = 102.8 kg for the 6-EVF-80, 4 × 31.5 kg = 126.0 kg for the 6-EVF-100, 4 × 40 kg = 160.0 kg for the 6-EVF-120, 4 × 45 kg = 180.0 kg for the 6-EVF-135 and 4 × 48.5 kg = 194.0 kg for the 6-EVF-150. Use those figures for the truck’s balance and the floor loading, not for a generic 48V pack.

    Q4. How long does a 48V forklift battery take to charge? The published charge acceptance is 80% charge in ≤ 4 hours, with a charger at the unit’s maximum charge current, and the charger itself should have a pulse function and temperature compensation, adjusting the float charge time seasonally against a 25 °C reference. The full float set point is 54.0 V and equalisation 56.4 V across the 48V pack. Charging a battery that has just come off a warm truck is not recommended: the published guidance is to charge on a cooled battery and to keep charging out of direct sun and out of enclosed high-temperature spaces.

    Q5. What is the difference between a C3 rating and a C10 rating? The rate at which the capacity is measured. The 6-EVF range publishes capacity at the 3-hour rate to a 1.75 V/cell cut-off, so the 6-EVF-100 delivers 100 Ah at C3. A C10 figure would be measured over ten hours to a lower cut-off and would normally read higher for the same cell. For a traction duty the 3-hour rate is the relevant number because the truck lifts under high current; for a standby duty the 10-hour rate is the relevant one. Never compare two quotations without the rate and the cut-off on both.

    Q6. Can different capacities be mixed in one 48V pack? Not in a pack that has to be charged and balanced as one unit. Each unit in a series pack must be the same model, and ideally from the same production batch, because the units age together and the pack’s usable capacity is set by the weakest unit. Mix a 6-EVF-100 with a 6-EVF-120 and the pack will be limited by the smaller unit for the rest of its life, with the larger unit repeatedly over- or under-charged depending on which end of the string is being measured.

    Q7. What temperature range can a 48V forklift battery work in? The published working range is −15 °C to 50 °C and the storage range is −20 °C to 45 °C. Self-discharge is ≤ 3% per month at 25 °C. A warehouse in Rotterdam or Durban sits comfortably inside that window; a covered dock in Chennai in May sits close to the upper end of the working range, and a bay in a cold store in Scandinavia approaches the lower end. Capacity falls outside the comfortable middle of the band, so the usable reserve in those conditions is lower than the nameplate figure and belongs in the sizing.

    Q8. What should be on the purchase order for a 48V forklift battery? The unit model and quantity, the series connection, the capacity rate and cut-off voltage, the published maximum charge current, the charger rating and the float and equalisation set points in volts for the pack, the case dimensions and terminal type, the weight per unit and the derived pack weight, the duty pattern the fleet intends to run, the batch reference, the test report referencing GB/T 32620.1-2016 and GB/T 32620.2-2016, and the arrival inspection procedure with the named laboratory.

    Expert Summary

    A forklift battery 48V pack is four 12V units in series, and every number that matters is published unit by unit. The 6-EVF-60 publishes 60 Ah at C3 to 1.75 V/cell, 258 × 170 × 160 mm, 18.8 ± 0.2 kg and 12.0 A maximum charge current; the 6-EVF-100 publishes 100 Ah, 330 × 170 × 218 mm, 31.5 ± 0.2 kg and 20.0 A; the 6-EVF-120 publishes 120 Ah, 407 × 170 × 240 mm, 40 ± 0.2 kg and 24.0 A; the 6-EVF-135 publishes 135 Ah, 338 × 172 × 280 mm, 45 ± 0.2 kg and 27.0 A; the 6-EVF-150 publishes 150 Ah, 483 × 170 × 240 mm, 48.5 kg and 30.0 A. All of them float at 13.5 V and equalise at 14.1 V, which is 54.0 V and 56.4 V across the pack and 2.25 V per cell in float, and all of them publish a 2-5 year float design life with a 350-600 cycle life at 50-80% depth of discharge.

    Four derived numbers settle most of the decisions. The pack energy is 48 V × Ah: 2,880 Wh for the 60 Ah build up to 7,200 Wh for the 150 Ah build. The pack weight is 4 × unit weight: 75.2 kg, 102.8 kg, 126.0 kg, 160.0 kg, 180.0 kg and 194.0 kg. The charger is 48V at the unit rating — 48V/20 A for the 6-EVF-100 build, 48V/30 A for the 6-EVF-150 build — because a series pack passes the same current through every unit. And the specific energy stays inside a narrow 36.0 to 38.3 Wh/kg band, which tells the buyer that a larger pack is heavier in proportion to what it stores rather than inefficient.

    The buyer who writes the unit model, the capacity rate, the charger rating, the set points and the pack weight onto the order line has a specification that any qualified factory can quote against and any workshop can check at the dock in Rotterdam, Jebel Ali, Santos, Lagos or Chennai. That is a short document, and it is what separates a fleet purchase that fits the truck from one that arrives and does not.

    Contact CHISEN

    Send the truck class, the shift pattern, the bay dimensions, the required runtime per shift and the quantity to the CHISEN export desk, and you will receive a quotation built on the published model data, the current lead time and the certification documents for your destination market.

    • Email: jack@chisen.cn or sales@chisen.cn
    • WhatsApp: +86 131 6622 6999
    • AGM range index: https://www.chisen.cn/en/AGMBattery/QTF.html
    • 6-EVF-60 model page: https://www.chisen.cn/en/6-EVF-60/12V60Ah.html
    • 6-EVF-100 model page: https://www.chisen.cn/en/6-EVF-100/12V100Ah.html
    • 6-EVF-120 model page: https://www.chisen.cn/en/6-EVF-120/12V120Ah.html
    • 6-EVF-135 model page: https://www.chisen.cn/en/6-EVF-135/12V135Ah.html
    • 6-EVF-150 model page: https://www.chisen.cn/en/6-EVF-150/12V150Ah.html

    Related reading on the CHISEN knowledge centre: traction battery duty-cycle sizing, AGM charge acceptance and equalisation scheduling, battery bay ventilation and temperature control, and fleet spare-unit matching procedures.

    CHISEN Battery — AGM valve-regulated lead-acid traction batteries for electric forklifts, stackers, AGVs, golf carts and sightseeing vehicles. 8 production bases, 70 million kVAh annual capacity, ISO 9001 and ISO 14001 certified.

    Related CHISEN Buyer Guides

  • 2V 100Ah Battery: OPzS2 Flooded vs OPzV2 Gel Tubular for Telecom, UPS and Solar (2026)

    2V 100Ah Battery: OPzS2 Flooded vs OPzV2 Gel Tubular for Telecom, UPS and Solar (2026)

    Answer First

    A 2V 100Ah battery is a single 2V tubular cell delivering 100 amp-hours at the C10 rate, and it is the smallest cell in the stationary tubular class that still carries a serious engineering footprint: 103 mm × 206 mm in plan, a total height of 409 mm for the flooded OPzS2-100 and 390 mm for the gel OPzV2-100, and 12.6 kg with electrolyte against 13.2 kg sealed. Twenty-four of them in series produce a 48V string of 48 V × 100 Ah = 4,800 Wh — the working voltage of nearly every telecom DC plant, most mid-size UPS cabinets and the smaller solar storage strings. The two chemistries are not interchangeable. The flooded OPzS2-100 needs filling, density setting, watering and ventilation; the gel OPzV2-100 arrives sealed with no service step and a published 30 A maximum charge current against 20 A for the flooded cell. This guide compares the two on published data only — capacity, geometry, weight, charge settings, internal resistance, temperature behaviour and string arithmetic — so the chemistry decision is made before a factory quotation is requested.

    Key Takeaways

    • A 2V 100Ah battery is one 2V cell, not a 12V block; a 48V string needs 24 cells and gives 48 V × 100 Ah = 4,800 Wh.
    • The OPzS2-100 flooded cell publishes 8.0 kg without electrolyte and 12.6 kg with electrolyte, so a 24-cell string weighs 192.0 kg dry and 302.4 kg filled.
    • The OPzV2-100 gel cell publishes 13.2 kg supplied filled and sealed, so the same 24-cell string weighs 316.8 kg — 14.4 kg more than the flooded string, with no filling step at all.
    • Maximum charge current is 20 A for the flooded cell (20 A ÷ 100 Ah = 0.2 C) and 30 A for the gel cell (30 A ÷ 100 Ah = 0.3 C). In a series string the current passes through every cell, so the string charges at the cell rating — not at the sum of the ratings.
    • Float is 2.23 V @25 °C and equalisation is 2.35 V @25 °C for both cells, with −3 mV/°C/cell compensation and a 20+ year design float life at 20 °C.
    • Internal resistance differs and so does its reference temperature: the flooded cell is published at ~1.0 mΩ @20 °C, the gel cell at ~1.1 mΩ @20 °C, which puts a 24-cell string at 24.0 mΩ and 26.4 mΩ respectively.
    • The flooded cell’s capacity falls to 85% at 0 °C and 65% at −15 °C on the 10-hour rate; the gel cell’s curve is published at about 80% at 0 °C and about 60% at −20 °C. Cold-climate sites cannot ignore either number.

    §1 — 2V 100Ah Battery Specifications

    Every row is read from the manufacturer datasheet for the cell named in the column, or derived by arithmetic from those values. Rows marked Datasheet (range setpoint) are the published charge and life setpoints that apply across the CHISEN tubular range; all other rows are taken from the individual cell datasheet.

    SpecificationOPzS2-100 (flooded)OPzV2-100 (gel)Source
    Nominal voltage2V2VDatasheet
    Rated capacity at C10 (1.80 Vpc, 20 °C)100 Ah100 AhDatasheet
    Dimensions L × W × H103 × 206 × 354 mm103 × 206 × 390 mmDatasheet
    Total height with terminals409 mm390 mmDatasheet
    Weight without electrolyte8.0 kgnot applicable — gel cells are supplied filledDatasheet
    Weight with electrolyte12.6 kg13.2 kgDatasheet
    Electrolyte mass per cell12.6 kg − 8.0 kg = 4.6 kgnoneArithmetic
    Maximum charge current20 A30 ADatasheet
    Charge current as a fraction of capacity20 A ÷ 100 Ah = 0.2 C30 A ÷ 100 Ah = 0.3 CArithmetic
    Float charge voltage2.23 V @25 °C2.23 V @25 °CDatasheet (range setpoint)
    Equalisation charge voltage2.35 V @25 °C2.35 V @25 °CDatasheet (range setpoint)
    Temperature compensation−3 mV/°C/cell−3 mV/°C/cellDatasheet (range setpoint)
    Design float life20+ years @20 °C20+ years @20 °CDatasheet (range setpoint)
    Internal resistance (fully charged)0.001 Ω @20 °C0.0011 Ω @20 °CDatasheet
    Self-discharge rate3% per month @20 °C2% per month @20 °CDatasheet
    Maximum discharge current (5 s)not published — request from factory1000 ADatasheet
    Short circuit currentnot published — request from factory1700 ADatasheet
    Discharge temperature rangenot published — request from factory−40 °C to 65 °CDatasheet
    Charge temperature rangenot published — request from factory−30 °C to 65 °CDatasheet
    Storage temperature rangenot published — request from factory−25 °C to 45 °CDatasheet
    TerminalCopper post M8, ø20 mm outer diameterFemale copper insert M8, 10-12 N·mDatasheet
    Container materialMolded case with sulfuric acid electrolyteABS container, UL94-V0 optionalDatasheet
    Electrolyte typeSulfuric acid, liquidImmobilised gelDatasheet
    StandardsDIN 40736-1IEC 60896-21/22, DIN 40472, IEC 61427, YD/T 1360, BS 6290 part 4, UL 1989Datasheet
    CertificationsEIC ISO 9001, CE, RU (UL recognised component)ISO 9001, ISO 14001, GB/T 28001, OHSAS 18001:2007, CE, UR (RU)Datasheet
    Energy per cell2 V × 100 Ah = 200 Wh2 V × 100 Ah = 200 WhArithmetic

    Two rows in that table carry more weight than they look. The first is the electrolytic mass: a flooded cell is 4.6 kg heavier filled than dry, which is 4.6 kg of sulfuric acid that a rack in Hamburg, Rotterdam or Durban has to carry, and that has to be added on site by a controlled procedure. The second is the operating temperature range, which the flooded datasheet does not publish at all. Where a cell datasheet does not state a value, the correct procurement action is to request it in writing from the factory rather than to substitute a number from a generic lead-acid chart.

    The OPzS2-100 datasheet also prints a discharge rate table measured at 20 °C to a 1.80 V cut-off, and that table is worth reading in full because it explains most capacity disputes. At the 1.80 V cut-off the cell returns 60 Ah at the 1-hour rate, 75 Ah at 3 hours, 85 Ah at 5 hours, 100 Ah at 10 hours, 107 Ah at 24 hours, 111 Ah at 48 hours, 115 Ah at 72 hours, 120 Ah at 100 hours, 122 Ah at 120 hours and 130 Ah at 240 hours. The C10 rating of 100 Ah sits inside that curve, and any comparison against a supplier who quotes “130 Ah” is a comparison against the 240-hour rate, not a better cell.

    §2 — The Pain

    Four failures recur on 2V 100Ah orders, and all four begin with a purchase order line that is too short.

    The first is a missing chemistry statement. “2V 100Ah tubular battery” is not a specification. It can be the OPzS2-100 flooded cell at 8.0 kg dry and 12.6 kg filled, or the OPzV2-100 gel cell at 13.2 kg sealed. The two have different installation steps, different vent requirements, different charge acceptance and different published cycle life curves. A quotation that carries no model code cannot be re-ordered against the same specification two years later, which means the real cost of the missing line is paid at the second shipment.

    The second is the charge current written as a sum instead of a limit. In a series string, the current that enters the first cell passes through all of them. Twenty-four cells rated at 20 A each do not accept 480 A; the string accepts 20 A. Any charger proposal that adds the per-cell ratings together describes a charger that would destroy the cells in a single cycle. The published numbers to write on the order are the per-cell maximum and the resulting string rating: 20 A for the flooded string, 30 A for the gel string.

    The third is the capacity figure quoted without its rate. A 2V 100Ah cell returns 100 Ah at the 10-hour rate and 130 Ah at the 240-hour rate, and returns 60 Ah if it is drawn in one hour. A buyer comparing two quotations — one quoting 100 Ah, one quoting 130 Ah — is comparing two discharge rates. The comparison only works when both cells are stated at the same rate and the same cut-off voltage, and when the cut-off is written down: 1.80 V per cell for a capacity rating.

    The fourth is the float setpoint left to the charger’s default. Float is 2.23 V @25 °C and equalisation is 2.35 V @25 °C, with −3 mV/°C/cell compensation. A string of 24 cells floating at the wrong setpoint drifts across the pack, the cells at the warm end age faster than the cells at the cool end, and the string develops a capacity spread that is invisible until a single cell fails to hold the string voltage.

    Buyers sourcing for Rotterdam, Jebel Ali, Santos, Lagos, Chennai, Port Said or Mombasa regularly receive quotations for “2V 100Ah tubular” with no datasheet reference, no chemistry statement and no charge settings. Such a quotation cannot be compared between two factories and cannot be defended at a technical audit.

    §3 — The Choice

    The decision between a flooded and a gel 2V 100Ah battery is a set of operating consequences, not a preference. The string arithmetic below is what each choice costs and delivers in a 24-cell 48V installation.

    48V string buildOPzS2-100 floodedOPzV2-100 gelSource
    Cells in series24 × 2 V = 48 V24 × 2 V = 48 VArithmetic
    String energy48 V × 100 Ah = 4,800 Wh48 V × 100 Ah = 4,800 WhArithmetic
    String weight, as delivered24 × 12.6 kg = 302.4 kg24 × 13.2 kg = 316.8 kgArithmetic
    String weight before filling24 × 8.0 kg = 192.0 kgnot applicableArithmetic
    Electrolyte mass to be added on site24 × 4.6 kg = 110.4 kgnoneArithmetic
    String internal resistance24 × 1.0 mΩ = 24.0 mΩ24 × 1.1 mΩ = 26.4 mΩArithmetic
    Maximum string charge current20 A (cell rating, not 24 × 20 A)30 A (cell rating, not 24 × 30 A)Datasheet
    Charge rate at 0.1 C10 A, roughly 10 hours to full10 A, roughly 10 hours to fullArithmetic
    Float set point across the string24 × 2.23 V = 53.52 V24 × 2.23 V = 53.52 VArithmetic
    Equalisation set point across the string24 × 2.35 V = 56.40 V24 × 2.35 V = 56.40 VArithmetic
    Installation stepfilling, density setting and ventilation requirednoneDatasheet
    Ongoing servicewatering on a published schedulenoneDatasheet
    Published cycle life at 100% DoDapproximately 750-800 cyclesapproximately 1,500 cyclesDatasheet
    Published cycle life at 80% DoDapproximately 1,100 cyclesapproximately 2,000 cyclesDatasheet
    Published cycle life at 50% DoDapproximately 1,800 cyclesapproximately 2,800 cyclesDatasheet
    Published full specificationOPzS2-100 model pageOPzV2-100 model pageModel page

    Read the two columns against each other and the trade becomes concrete.

    The flooded OPzS2-100 is 14.4 kg lighter as delivered across a 24-cell string — 302.4 kg against 316.8 kg — because the electrolyte travels separately and is added on site. That saving is real for a coastal installation where freight is billed by weight, and it is paid for with a filling procedure, a density measurement on every cell, a watering schedule and a ventilation requirement. On self-discharge the gel cell wins outright: the flooded cell is published at 3% per month at 20 °C against 2% per month for the gel cell, which matters for a cell stored off-line through a rainy season or shipped to site a month early.

    The gel OPzV2-100 wins on the cycle side. Its datasheet curve gives approximately 1,500 cycles at 100% depth of discharge against approximately 750-800 for the flooded cell, and approximately 2,000 cycles at 80% depth of discharge against approximately 1,100. For a site that cycles daily — a solar plant with a seasonal storage shift, a telecom site with frequent generator start-stop, an off-grid microgrid in a mining camp — that difference is the whole life of the installation. The gel cell also publishes a short circuit current of 1700 A and a 5-second maximum discharge current of 1000 A, which are the figures a protective device has to be set against.

    For a telecom DC plant in Jebel Ali or Chennai, where floor space and maintenance access are constrained and the room is often sealed, the gel route removes an entire service operation from the asset: there is no filling and no watering on any cell in the string. For a ground-mounted solar site in Santos or Durban where ventilation is available and the budget is tighter, the flooded route is a legitimate, well-understood choice.

    The wider flooded tubular range, covering 2V cells from 100 Ah to 3000 Ah, is indexed on the CHISEN flooded tubular battery page.

    §4 — The Framework

    Seven checks turn a 2V 100Ah enquiry into an order that can be built, shipped, installed and defended.

    1. Name the model and the chemistry. Write “OPzS2-100 flooded” or “OPzV2-100 gel”. Never “2V 100Ah tubular”, which is an instruction to buy whichever the factory has that month.

    2. State the weight basis. For the flooded cell, write 8.0 kg without electrolyte and 12.6 kg with electrolyte. For the gel cell, write 13.2 kg. Then apply the string factor: 24 cells gives 192.0 kg and 302.4 kg for the flooded string, or 316.8 kg for the gel string. Structural checks should be made on the filled figure.

    3. Write the charge settings to three decimals of a volt. Float 2.23 V @25 °C, equalisation 2.35 V @25 °C, compensation −3 mV/°C/cell. Across a 24-cell string that is 53.52 V float and 56.40 V equalisation, and for solar and wind service the OPzV2-100 datasheet moves to a regulation setting of 2.40 ± 0.01 V/cell @25 °C with float at 2.27 ± 0.005 V/cell @25 °C, an over-voltage disconnect at 2.45 ± 0.01 V/cell, a low-voltage alarm at 1.95 ± 0.005 V/cell, a low-voltage disconnect at 1.90 ± 0.005 V/cell and a load reconnect at 2.09 ± 0.01 V/cell. Put these in the charger configuration table, not in a general note.

    4. Rate the charger from the cell, not from the arithmetic sum. The flooded cell accepts 20 A, the gel cell 30 A; a series string charges at that current. A 30 A charger on a 24-cell gel string is correct. A charger sized on the sum of the per-cell ratings is not.

    5. Ask for the rate table, not just the headline capacity. For the OPzS2-100 that table is published at 20 °C to a 1.80 V cut-off, running from 60 Ah at the one-hour rate to 130 Ah at the 240-hour rate. For the OPzV2-100 the constant current table gives 15.0 A at ten hours, 26.8 A at five hours, 39.4 A at three hours and 65.0 A at one hour, to the same 1.80 V cut-off. If a supplier will not supply the rate table, the capacity claim cannot be verified.

    6. Confirm the case, the terminal and the rack. 103 × 206 × 354 mm flooded with a 409 mm total height against 103 × 206 × 390 mm gel. The footprint is identical and the height differs by 19 mm, which matters in a stacked rack with limited clearance. The flooded cell uses a copper M8 post with a ø20 mm outer diameter; the gel cell uses a female copper M8 insert at 10-12 N·m.

    7. Agree the arrival test. A sample capacity check at C10 to 1.80 Vpc, a float voltage check across the string, and for flooded cells an electrolyte density check on every cell, with a named laboratory for re-inspection. For long sea routes to Santos, Jebel Ali, Lagos, Port Said or Mombasa, agree the state-of-charge at shipment, because self-discharge at 3% per month for the flooded cell is real money on a 4,800 Wh string.

    §5 — The Trust

    The OPzS2 and OPzV2 tubular ranges are produced inside a manufacturer that operates 8 production bases with an annual capacity of 70 million kVAh, under a quality management system certified to ISO 9001, with ISO 14001 covering the environmental system, and CE, UL and IEC conformity for the destination markets. Every figure in this article is taken from the individual datasheet for each cell rather than from a marketing summary, and the complete flooded tubular range is indexed on the CHISEN flooded tubular page. Two points deserve emphasis for a buyer who will be asked to pay for assurance.

    First, a certificate covers a management system, a scope and a date. ISO 9001 confirms that the plant runs documented procedures and acts on non-conformity; it does not confirm that a particular cell holds 100 Ah at C10. That is the job of the datasheet, the type test and the acceptance test. Ask for the certificate number, the scope statement, the registered address and the validity dates, then verify the cell on its own published data.

    Second, the 20+ year float life figure has a precise condition attached to it: it is a design life at 20 °C. A string operated in a container in Jebel Ali or a plant room in Chennai sees a higher average temperature, and the life figure moves with temperature even though the label does not. That is not a weakness in the cell; it is the reason the datasheet states the temperature. Use the figure as a design input, and state the operating temperature on the order so the supplier can confirm what they stand behind.

    A third point is specific to this pair of cells, and it is a disclosure rather than an objection. The flooded OPzS2-100 datasheet publishes its maximum charge current, internal resistance, dimensions, weights and rate tables, but it does not publish an operating temperature range for discharge, charge or storage. The gel OPzV2-100 datasheet publishes all three. Where a datasheet is silent, the correct action is to ask the factory for the missing range in writing and to record the answer on the order, not to carry a figure across from a different cell or a generic chart. That single discipline — asking for the number that is missing rather than assuming the number that is convenient — is what separates a buyer who can verify a cell from one who can only accept a claim.

    §6 — FAQ

    Q1. Is a 2V 100Ah battery the same as a 12V 100Ah battery? No, and this is a frequent source of confusion. A 2V 100Ah battery is a single 2V cell, and a 12V 100Ah battery is normally six 2V cells in series with a common case and a common set of terminals. The six-cell version carries 12V × 100 Ah = 1,200 Wh against 2 V × 100 Ah = 200 Wh for one cell, and it cannot be opened for individual cell maintenance. For stationary strings, engineers normally specify the 2V cell so that individual cells can be replaced; for small enclosures, the 12V block is more convenient.

    Q2. How many 2V 100Ah batteries do I need for a 48V system? Twenty-four. 24 × 2 V = 48 V, and the string capacity is 48 V × 100 Ah = 4,800 Wh. The string weight is 24 × 12.6 kg = 302.4 kg for the flooded OPzS2-100 and 24 × 13.2 kg = 316.8 kg for the gel OPzV2-100. For a 72V system, use 36 cells for 72 V × 100 Ah = 7,200 Wh; for a 96V system, use 48 cells for 96 V × 100 Ah = 9,600 Wh and a string weight of 48 × 13.2 kg = 633.6 kg with the gel cell.

    Q3. What is the difference between a flooded OPzS2-100 and a gel OPzV2-100? Chemistry and installation. The flooded cell is published at 8.0 kg without electrolyte and 12.6 kg with electrolyte, needs filling and density setting on site, needs watering on a published schedule, and needs ventilation. The gel cell is published at 13.2 kg supplied filled and sealed, needs no filling and no watering, and can be installed in an enclosed room. The flooded cell accepts 20 A of charge current and publishes a cycle life of approximately 750-800 cycles at 100% depth of discharge; the gel cell accepts 30 A and publishes approximately 1,500 cycles at the same depth. Both float at 2.23 V @25 °C, equalise at 2.35 V @25 °C with −3 mV/°C/cell compensation, and carry a 20+ year design float life at 20 °C.

    Q4. Why does the datasheet show both 100 Ah and 130 Ah for the same cell? Because the discharge rate differs. The C10 rating of 100 Ah is measured to a 1.80 V cut-off. The OPzS2-100 rate table, also measured at 20 °C to 1.80 V, returns 60 Ah at the one-hour rate, 75 Ah at 3 hours, 85 Ah at 5 hours, 100 Ah at 10 hours, 107 Ah at 24 hours, 111 Ah at 48 hours, 115 Ah at 72 hours, 120 Ah at 100 hours, 122 Ah at 120 hours and 130 Ah at 240 hours. A supplier quoting 130 Ah is quoting the 240-hour rate. Always compare two cells at the same rate and the same cut-off voltage.

    Q5. What charge voltage should I set for a 2V 100Ah battery? For standby service, float 2.23 V @25 °C with 2.35 V @25 °C equalisation and −3 mV/°C/cell compensation, which is 53.52 V float and 56.40 V equalisation across a 24-cell string. For solar and wind service the OPzV2-100 datasheet moves the regulation setting to 2.40 ± 0.01 V/cell @25 °C with float at 2.27 ± 0.005 V/cell @25 °C, an over-voltage disconnect at 2.45 ± 0.01 V/cell, a low-voltage alarm at 1.95 ± 0.005 V/cell, a low-voltage disconnect at 1.90 ± 0.005 V/cell and a load reconnect at 2.09 ± 0.01 V/cell. Confirm the setting against the datasheet for the exact cell on your order rather than against a general lead-acid chart.

    Q6. What charger do I need for a 48V string of 2V 100Ah batteries? A 48V charger rated at the cell’s maximum charge current, because current in a series string passes through every cell. For the flooded OPzS2-100 that is 20 A, which is 0.1 C on a 4,800 Wh string and gives roughly 10 hours to full at the 0.1 C rate. For the gel OPzV2-100 that is 30 A. Sizing the charger by adding the per-cell ratings together is a common specification error, and it will over-drive the cells.

    Q7. Can I mix flooded and gel cells in the same string? No. A series string must be built from cells of the same chemistry, the same model and ideally one production batch. A flooded cell and a gel cell have different internal resistance, different self-discharge rates, different equalisation behaviour and different gas output, so no single charge setpoint serves both. Build the string from one chemistry and keep spare cells of the same model and batch for replacement.

    Q8. Does a 2V 100Ah battery lose capacity in cold climates? Yes, and the published figures differ by chemistry. On the 10-hour rate the OPzS2-100 returns 108% at 40 °C, 100% at 20 °C, 85% at 0 °C and 65% at −15 °C. The OPzV2-100 curve is published at approximately 80% at 0 °C and approximately 60% at −20 °C. For a container site in Rotterdam or an unheated plant room in Mombasa, the usable capacity in winter is lower than the nameplate figure, and that belongs in the sizing calculation.

    Q9. What should be on the purchase order for a 2V 100Ah battery? The exact model and chemistry, the terminal and torque, the float and equalisation voltages with their reference temperature, the temperature compensation coefficient, the maximum charge current, the design float life and its reference temperature, the case dimensions, the weight basis and tolerance, the batch reference, the required test certificate, and the acceptance procedure on arrival. For container shipments to Santos, Jebel Ali, Lagos or Port Said, add the agreed laboratory and the state-of-charge requirement at shipment.

    Expert Summary

    A 2V 100Ah battery is fully specified in public. The OPzS2-100 flooded cell publishes 103 × 206 × 354 mm with a 409 mm total height, 8.0 kg without electrolyte and 12.6 kg with electrolyte, 20 A maximum charge current, 2.23 V float at 25 °C, 2.35 V equalisation, −3 mV/°C/cell compensation, 0.001 Ω @20 °C internal resistance and a 20+ year design float life at 20 °C. The OPzV2-100 gel cell publishes 103 × 206 × 390 mm, 13.2 kg, 30 A maximum charge current, the same charge setpoints, 0.0011 Ω @20 °C internal resistance, a 1700 A short circuit current and the same 20+ year float life. Twenty-four of either give 48 V × 100 Ah = 4,800 Wh.

    Three numbers decide most of the projects, and all three follow directly from the published cell data. The 110.4 kg of electrolyte in a flooded 24-cell string — 24 × 4.6 kg — decides whether the site has the filling capability, the drainage and the ventilation to take it. The 24.0 mΩ and 26.4 mΩ string internal resistance figures, from 24 × 1.0 mΩ and 24 × 1.1 mΩ, decide the cable and busbar design at the plant in Hamburg or the substation in Chennai. And the 20 A versus 30 A cell charge rating decides the charger: a series string charges at the cell rating, not at the sum of twenty-four of them.

    The buyer who writes those three numbers, the charge setpoints and the batch reference onto the order line has a specification that any qualified factory can quote against and any inspector can check at the port. That is a short document, and it is the whole difference between a defensible purchase and a dispute.

    Contact CHISEN

    Send the application, the string voltage and cell count, the required capacity, the installation environment and the quantity to the CHISEN export desk, and you will receive a quotation built on the published datasheet, the current lead time and the certification documents for your destination market.

    • Email: jack@chisen.cn or sales@chisen.cn
    • WhatsApp: +86 131 6622 6999
    • Flooded tubular index: https://www.chisen.cn/en/Tubularfloodedbattery/OPzS.html
    • Gel tubular index: https://www.chisen.cn/en/TubularGelBattery/OPzV.html
    • OPzS2-100 model page: https://www.chisen.cn/en/OPzS2-100/2V100Ah.html
    • OPzV2-100 model page: https://www.chisen.cn/en/OPzV2-100/2V100Ah.html

    Related reading on the CHISEN knowledge centre: tubular cell charge setpoints, electrolyte filling and density procedures, string-level cell matching, and reserve capacity calculation for telecom DC plants.

    CHISEN Battery — flooded and gel tubular lead-acid cells for telecom, solar, UPS, railway and substation applications. 8 production bases, 70 million kVAh annual capacity, ISO 9001 and ISO 14001 certified.

    Related CHISEN Buyer Guides

  • CHISEN Factory: How to Audit a Lead-Acid Battery Manufacturer (2026)

    CHISEN Factory: How to Audit a Lead-Acid Battery Manufacturer (2026)

    Answer First

    The CHISEN factory is a manufacturing operation, not a trading desk: the CHISEN brand was established in 2002 and has specialised in lead-acid tubular batteries for 20+ years, it operates 8 production bases with an annual capacity of 70 million kVAh, it publishes a product line of 200+ models spanning 2V, 6V, 8V and 12V from 4Ah to 3000Ah, and it exports to 60+ countries. More useful to a buyer than any of those figures is the evidence behind them — 610 English product pages, 69 model codes with a dedicated specification page each, 100% factory inspection before shipment covering capacity, internal resistance, voltage and appearance, statistical process control on plate pasting, group assembly, formation and sealing, and third-party pre-shipment inspection through SGS, TUV, BV or CTI on customer request. This guide turns that evidence into the seven checks a buyer can run on any lead-acid battery factory, including CHISEN, before an order is signed.

    Key Takeaways

    • A factory claim is only worth what a buyer can verify. Per-model datasheets, batch references and inspection records are evidence; “factory direct” on a quotation header is not.
    • CHISEN publishes 8 production bases and 70 million kVAh of annual capacity, and also publishes the physical data that capacity has to produce: 610 English product pages covering 69 model codes, each with its own specification page.
    • The product line spans 2V, 6V, 8V and 12V from 4Ah to 3000Ah across 200+ models, which means a buyer can hold the supplier to a second source on a specific model rather than accepting a range-level promise.
    • Charge settings are published per product range, not per marketing page: 2.23 V float and 2.35 V equalisation at 25 °C with −3 mV/°C/cell compensation and a 20+ year design float life at 20 °C for the tubular classes, and 13.5 V float with 14.1 V equalisation for the 12V VRLA classes.
    • 100% factory inspection before shipment covers four tests — capacity, internal resistance, voltage and appearance — and the same manufacturer supports third-party pre-shipment inspection by SGS, TUV, BV or CTI on customer requirement.
    • Statistical process control is applied to the four processes that actually decide cell consistency: plate pasting, group assembly, formation and sealing. A sample that passes and a production batch that drifts usually differ in one of those four.
    • 100,000+ units of mainstream models are held for immediate shipment, which is the single most useful logistical fact in a supply agreement for a buyer who cannot wait on a production slot.

    §1 — What the CHISEN Factory Publishes

    Every row below is a published figure taken from the manufacturer’s own material — the company profile, the product pages, the individual datasheets and the English site index — and the source is stated in each case.

    ItemPublished figureSource
    Brand established2002Company profile
    Years specialising in tubular batteries20+ yearsCompany profile
    Production bases8 production basesCompany profile
    Annual production capacity70 million kVAhCompany profile
    Complete product line200+ modelsCompany profile
    Voltage levels covered2V / 6V / 8V / 12VCompany profile
    Capacity range covered4Ah to 3000AhCompany profile
    Export reach60+ countriesCompany profile
    Mainstream models held in stock100,000+ units, immediate shipmentCompany profile
    English catalogue pages610 indexed URLs on the English siteEnglish site index
    Model codes with a dedicated specification page69English site index
    Tubular charge setpoints2.23 V float, 2.35 V equalisation, −3 mV/°C/cellDatasheet
    Tubular design float life20+ years at 20 °CDatasheet
    12V VRLA charge setpoints13.5 V float, 14.1 V equalisationModel page
    Pre-shipment inspection100% of units: capacity, internal resistance, voltage, appearanceCompany profile
    Process control appliedSPC on plate pasting, group assembly, formation, sealingCompany profile
    Third-party pre-shipment inspectionSGS, TUV, BV or CTI, per customer requirementCompany profile
    Quality management systemISO 9001Datasheet and company profile
    Environmental management systemISO 14001Datasheet and company profile
    Occupational health and safetyGB/T 28001, OHSAS 18001:2007Datasheet
    Tubular product standardsIEC 60896-11, IEC 60896-21/22, DIN 40736-1, DIN 40472, IEC 61427, YD/T 1360, BS 6290 part 4, UL 1989, Eurobat long-life guideDatasheet
    12V VRLA traction standardsGB/T 32620.1-2016, GB/T 32620.2-2016, JB/T 2599Model page
    Market and environmental complianceCE, UR (RU), RoHS, REACH, WEEE, MSDS, IMDG sea freightDatasheet and company profile

    Two rows in that table carry the most weight in a first audit, and neither is a capacity figure.

    The first is the third-party pre-shipment inspection row. A manufacturer that will let SGS, TUV, BV or CTI inspect the goods before loading is making a different commitment from one that only signs its own paperwork, because the inspection body is hired by the buyer’s side and reports to the buyer’s side. That single service converts a good-faith factory claim into a checkable event with a date on it.

    The second is the process control row. Plate pasting, group assembly, formation and sealing are the four stages where cell-to-cell variation is actually created — the pasting line controls the grid mass, the group assembly controls plate alignment and inter-cell distance, the formation stage controls the initial oxide structure, and the sealing step controls the seal integrity that determines whether a cell loses water in service. A supplier that names those four stages has named the four places where a delivered batch can drift from the sample the buyer approved. Suppliers who cannot name them are describing a warehouse, not a factory.

    §2 — The Pain

    Four failure patterns account for most of the disappointment that follows an unverified factory claim.

    The first is the label with nothing behind it. “Factory direct” appears on the header of quotations from trading companies, from agents who own no production equipment, and from manufacturers. The label is identical in all three cases because it costs nothing to print. What separates them is not the label but the depth of published data: a manufacturer publishes a specification page for each model with dimensions, weight, terminal type, internal resistance and charge current, and the documents carry the standards the cell was built against. A trading desk can copy a catalogue; it cannot produce 69 model-specific pages and the type-test reports behind them.

    The second is a capacity claim without a number, or with a number that cannot be checked. “Large scale manufacturer” and “annual output 100 million units” are both common. The second one is worse than the first, because it invites a buyer to assume that a high output figure means the model in question is actually produced. The check is simple: ask what share of the claimed capacity is the specific model you are buying, and ask for the mainstream stock position on that model. A published answer of 100,000+ units of mainstream models in stock is a better commercial commitment than any capacity claim, because it is a statement about goods that exist.

    The third is a certificate without a scope. ISO 9001 is issued to a legal entity, against a scope statement, for a set of sites, with a validity period. A certificate held by a sales company in another country, or covering a different product line, says nothing about the plant that will make your cells. Buyers routinely accept a scan of a certificate without checking the name, the address, the scope, the issuing body or the expiry date, and then treat a factory audit question as closed. It is not closed; it is unanswered.

    The fourth is the gap between the approved sample and the production batch. A sample that passes a capacity test proves that one cell can meet the datasheet. It does not prove that the four thousand cells in the pallet will. The gap is created in the four controlled processes, which is why a supplier’s answer to “how do you control consistency” is either specific — plate pasting, group assembly, formation, sealing — or it is not an answer at all. This is also why batch references matter: a batch reference on every cell and on the packing list is what allows a mismatch to be resolved at the port without a laboratory argument.

    §3 — The Choice

    The practical question is not whether to buy from a factory, but which factory documentation to demand. The table below lists the seven documents that carry the evidence, what each one proves, and what the CHISEN example looks like.

    Document to demandWhat it provesMinimum acceptable contentCHISEN published example
    Per-model specification sheetThat the model exists as a physical productDimensions, weight, terminal type, capacity rate and cut-off, internal resistance, maximum charge current, charge setpoints with reference temperature, design life with its temperature69 model codes, each with a dedicated specification page; for example 103 × 206 × 390 mm and 13.2 kg for the OPzV2-100 at 2V 100Ah
    Cell-level charge setpointsThat the factory controls its own chemistryFloat, equalisation, compensation coefficient and design life, each with a reference temperature2.23 V float and 2.35 V equalisation at 25 °C with −3 mV/°C/cell and a 20+ year design float life at 20 °C for tubular; 13.5 V float and 14.1 V equalisation for the 12V VRLA range
    Management system certificatesThat documented procedures exist and are auditedCertificate number, scope statement, registered address, issuing body, issue and expiry datesISO 9001 and ISO 14001, with GB/T 28001 and OHSAS 18001:2007 for occupational safety, and CE, UR (RU), RoHS, REACH, WEEE, MSDS and IMDG documentation
    Product standard complianceThat the cell was built to a named specificationThe standard numbers with the part they coverIEC 60896-11, IEC 60896-21/22, DIN 40736-1, DIN 40472, IEC 61427, YD/T 1360, BS 6290 part 4, UL 1989, plus GB/T 32620.1-2016 and GB/T 32620.2-2016 for traction
    Pre-shipment inspection recordThat every unit, not a sample, was tested before loadingWhich tests, on what proportion, recorded per shipment100% factory inspection before shipment: capacity test, internal resistance test, voltage test and appearance inspection
    Process control statementThat variation is managed rather than inspected outThe specific controlled processes and the control methodSPC statistical process control on plate pasting, group assembly, formation and sealing
    Batch and traceability recordThat a delivered unit can be traced to its productionBatch reference on every cell and on the packing list, with a re-inspection routeBatch references carried per cell and per shipment, with third-party pre-shipment inspection available through SGS, TUV, BV or CTI on customer requirement

    Read the last two rows again, because they are the difference between a supplier and a vendor. Inspection finds defects after they exist. Process control prevents them from being created in the first place. A factory that tests 100% of units and controls none of its processes is shipping a measured version of whatever its four uncontrolled processes produce; a factory that controls four named processes can then measure 100% of units and get a meaningful result.

    There is a practical corollary for procurement. If a supplier cannot produce the seven documents above for the model you are buying, the commercial conversation is about a distribution relationship, not a manufacturing one, and the two have different pricing, different lead times and different remedies when something arrives wrong. Deciding which one you are in is cheaper than discovering it at the port.

    The technical depth behind these documents is browsable directly: the flooded tubular range is indexed on the CHISEN flooded tubular battery page, the gel tubular range on the CHISEN gel tubular page, and the company profile on the CHISEN about page.

    §4 — The Framework

    Seven checks run in sequence will separate a manufacturer from a trading desk in under an hour, and they can be run from a laptop before anyone travels.

    1. Test the catalogue depth, not the catalogue size. Ask for the specification sheet of the exact model on your order — a single model, not a range. Then ask for a second model in a different voltage class. A manufacturer answers both from its own documentation; a trading desk answers the first from a PDF and stalls on the second.

    2. Check that the charge setpoints are published with a reference temperature. “Float 2.23 V” is half an answer; “float 2.23 V @25 °C, equalisation 2.35 V @25 °C, −3 mV/°C/cell compensation, 20+ year design float life at 20 °C” is a specification a charger can be programmed from. The same discipline applies to the 12V VRLA range, where the published figures are 13.5 V float and 14.1 V equalisation per 12V unit.

    3. Ask what the factory makes, in units. Require the number of production bases, the annual capacity, the number of models, the voltage and capacity span, the export reach and the stock position on your model. A manufacturer answers with figures: 8 production bases, 70 million kVAh annually, 200+ models across 2V, 6V, 8V and 12V from 4Ah to 3000Ah, 60+ countries, and 100,000+ units of mainstream models held for immediate shipment.

    4. Read the certificates properly. Certificate number, scope statement, registered address, issuing body, issue date and expiry date. ISO 9001 and ISO 14001 are the management system baseline; the product compliance set is what actually connects the cell to the market, and it is a different document set entirely.

    5. Ask how every unit is checked before loading, and by whom. The answer should name the tests and the proportion, and should tell you whether an independent body can be appointed. The CHISEN published position is 100% inspection before shipment covering capacity, internal resistance, voltage and appearance, with SGS, TUV, BV or CTI available on customer requirement.

    6. Ask which processes are statistically controlled, and require the four to be named. Plate pasting, group assembly, formation and sealing. If the answer is general rather than specific, you have learned that variation is being inspected out rather than prevented.

    7. Close the loop with traceability and a re-inspection route. Require a batch reference on every cell and on the packing list, and agree in advance which laboratory will repeat the acceptance test on arrival. For shipments into Santos, Jebel Ali, Lagos or Port Said, add the agreed state-of-charge at shipment, because a lead-acid cell’s self-discharge over a 30-day voyage is a measurable cost.

    §5 — The Trust

    The CHISEN factory’s own published position is the evidence above: established in 2002, 20+ years specialising in lead-acid tubular batteries, 8 production bases, 70 million kVAh of annual capacity, 200+ models from 4Ah to 3000Ah, exported to 60+ countries, with 100,000+ units of mainstream models available for immediate shipment and 610 indexed English catalogue pages covering 69 model codes. Management systems are certified to ISO 9001 and ISO 14001, occupational safety to GB/T 28001 and OHSAS 18001:2007, and market compliance runs through CE, UR (RU), RoHS, REACH, WEEE, MSDS and IMDG sea freight documentation. Every unit is inspected before shipment, four key processes are under statistical process control, and an independent inspection body can be appointed on buyer request.

    The reason that matters to a buyer is not the list itself. It is that the list is verifiable by someone who is not the supplier. The certification bodies are named, the standards are numbered, the model pages are public, the charge setpoints are public, the inspection regime is public, and the stock position is stated in units. A buyer in Rotterdam or Chennai can check every one of those without a factory visit and without a commercial relationship. That is what separates a manufacturer from a trading desk, and it is the reason the seven checks in §4 work on any supplier: they are all answerable in writing, and a refusal to answer one of them is itself an answer.

    §6 — FAQ

    Q1. How do I verify that a battery supplier is a real factory? Run the seven checks in this guide: demand a specification sheet for the exact model, then for a second model in a different voltage class; require charge setpoints with reference temperatures; require capacity, model count and stock figures in units; read the certificates for number, scope, address and validity dates; ask how every unit is inspected before loading and whether an independent body may be appointed; ask which processes are statistically controlled and require the specific ones to be named; and require batch traceability with a re-inspection route. A manufacturer answers all seven from its own documents. A trading desk stalls on the second or the sixth.

    Q2. What is the practical difference between buying from a factory and from a trading company? Three things. First, price: the factory’s quotation is built on its own published cell data, so it can be checked against the datasheet. Second, lead time: a factory with 8 production bases, 70 million kVAh of annual capacity and 100,000+ units of mainstream models in stock can commit to a shipping date from stock rather than from a production slot. Third, recourse: when a cell arrives out of specification, the factory that made it can trace the batch, and a trading company cannot.

    Q3. How big is the CHISEN factory? The published figures are 8 production bases, 70 million kVAh of annual capacity, a product line of 200+ models spanning 2V, 6V, 8V and 12V from 4Ah to 3000Ah, and export to 60+ countries since the brand was established in 2002. The company also reports 100,000+ units of mainstream models held in stock for immediate shipment, and the English site carries 610 indexed pages covering 69 model codes.

    Q4. Which certifications should I require from a lead-acid battery factory? The management system baseline is ISO 9001 for quality and ISO 14001 for the environment; occupational health and safety certification is worth asking for on any line with manual handling. The more decisive set is product compliance, because it is what connects a specific cell to a specific market: IEC 60896-11 for flooded stationary lead-acid batteries, IEC 60896-21 and -22 for valve-regulated types, DIN 40736-1 and DIN 40472 for tubular construction, IEC 61427 for renewable-energy storage, UL 1989 and BS 6290 part 4 for market access, and GB/T 32620.1-2016 and GB/T 32620.2-2016 for traction applications.

    Q5. How do I check that the battery I receive matches the datasheet? Agree the acceptance procedure before the goods ship, not after they arrive. The minimum is a capacity test at the stated rate to the stated cut-off voltage, an internal resistance check, a float voltage check, and an appearance inspection, with the proportion stated — the CHISEN published position is 100% inspection before shipment on all four tests. Add a named laboratory that may repeat the test on arrival, and require a batch reference on every cell and on the packing list so that a deviation can be investigated rather than argued about.

    Q6. What does 100% factory inspection actually cover on a lead-acid battery? Four tests: a capacity test, an internal resistance test, a voltage test and an appearance inspection. The internal resistance test is the one buyers most often overlook, and it is the one that detects a cell with poor inter-cell connections or a sealing problem before it fails on site. Appearance inspection catches the case damage, terminal deformation and contamination that cause early failures in handling.

    Q7. Why should I care about batch traceability for batteries? Because lead-acid cells vary within a production run, and because the variation is created in four specific processes — plate pasting, group assembly, formation and sealing — rather than uniformly across the pallet. A batch reference on every cell and on the packing list is what allows a buyer to determine whether an underperforming cell belongs to an isolated unit or to a run, and it is the difference between a warranty claim that is processed and one that is disputed.

    Q8. What should be in the supply agreement with a battery manufacturer? The model code and chemistry, the published specification sheet attached as an annex, the charge setpoints with their reference temperatures, the temperature compensation coefficient, the design life and the temperature it is rated at, the weight basis and tolerance for a flooded cell, the terminal type and torque, the agreed production batch practice, the pre-shipment inspection scope, the third-party inspection arrangement, the acceptance test and laboratory, the agreed state-of-charge at shipment, the delivery term against the published stock position, and the documents to accompany the shipment — type-test reports, the certificate set and the packing list with batch references.

    Expert Summary

    A CHISEN factory enquiry is auditable before anyone travels, because the manufacturer publishes what an audit would ask for. Established in 2002 with 20+ years in tubular lead-acid, the company operates 8 production bases at 70 million kVAh of annual capacity and publishes 200+ models across 2V, 6V, 8V and 12V from 4Ah to 3000Ah, exported to 60+ countries, with 100,000+ units of mainstream models in stock for immediate shipment and 610 English catalogue pages covering 69 model codes.

    Three of those published facts do the real work in an audit. The per-model specification pages, with 2.23 V float and 2.35 V equalisation at 25 °C, −3 mV/°C/cell compensation and a 20+ year design float life at 20 °C for the tubular classes and 13.5 V float with 14.1 V equalisation for the 12V VRLA classes, prove that the supplier controls its own chemistry rather than reselling someone else’s. The 100% pre-shipment inspection regime covering capacity, internal resistance, voltage and appearance, with SGS, TUV, BV or CTI available on buyer request, proves that the goods are checked before they are loaded. And the statistical process control over plate pasting, group assembly, formation and sealing proves that cell consistency is produced rather than inspected for after the fact.

    Those three are the checklist to carry to any factory, in any country, on any quotation. Apply them to CHISEN and to every other supplier on the same enquiry, and the comparison stops being a matter of who answered more confidently and becomes a matter of what was answered in writing. A factory that answers all three has shown you how it makes the cell; a supplier that answers none has shown you something else entirely.

    Contact CHISEN

    Send the models, the quantities, the destination market and the required documentation to the CHISEN export desk, and you will receive a quotation built on the published specification data, the current stock position and the certification package for your market.

    • Email: jack@chisen.cn or sales@chisen.cn
    • WhatsApp: +86 131 6622 6999
    • Company profile: https://www.chisen.cn/en/about.html
    • Flooded tubular index: https://www.chisen.cn/en/Tubularfloodedbattery/OPzS.html
    • Gel tubular index: https://www.chisen.cn/en/TubularGelBattery/OPzV.html
    • Knowledge centre: https://www.chisen.cn/en/sys-nr/knowledge

    Related reading on the CHISEN knowledge centre: incoming battery inspection procedures, type-test report reading, batch traceability and warranty claims, and charge setpoint configuration for tubular and VRLA installations.

    CHISEN Battery — lead-acid tubular, VRLA and traction manufacturing across 8 production bases, 70 million kVAh annual capacity, ISO 9001 and ISO 14001 certified, exporting to 60+ countries.

  • 12V 150Ah Battery: Deep-Cycle Sizing for Solar Storage, AGV Fleets and Telecom Backup (2026)

    12V 150Ah Battery: Deep-Cycle Sizing for Solar Storage, AGV Fleets and Telecom Backup (2026)

    Answer First

    A 12V 150Ah battery is a sealed valve-regulated lead-acid block that delivers 150 amp-hours at the C3 discharge rate from a 12V unit, and it is the standard building block for 48V and 72V deep-cycle installations in telecom backup, solar storage and automated guided vehicle fleets. The published specification that governs every decision is short and specific: 150 Ah at C3, a 483 × 170 × 240 mm case, 48.5 ± 0.2 kg, float at 13.5 V, equalisation at 14.1 V, maximum charge current 30.0 A, and 350–600 cycles at 50–80% depth of discharge with a 2–5 year design life. Four 12V 150Ah cells in series give a 48V bank of 48 V × 150 Ah = 7,200 Wh weighing 4 × 48.5 kg = 194.0 kg. This guide works through those figures, compares the 6-EVF-150 against the 6-EVF-120, 6-EVF-100, 6-EVF-80 and 6-EVF-60, and sets out the checks a buyer should complete before ordering into Lagos, Jebel Ali, Chennai, Santos or Durban.

    Key Takeaways

    • A 12V 150Ah battery is rated 150 Ah at the C3 rate and 13.5 V float across the six cells of the block — capacity quoted without the rate basis is not a specification.
    • The 6-EVF-150 publishes 483 × 170 × 240 mm and 48.5 ± 0.2 kg, the largest case in the EVF range, which is what makes it a bank product rather than a mobility product.
    • Four cells give a 48V bank of 48 V × 150 Ah = 7,200 Wh at 4 × 48.5 kg = 194.0 kg; six cells give a 72V bank of 72 V × 150 Ah = 10,800 Wh at 6 × 48.5 kg = 291.0 kg.
    • The published maximum charge current is 30.0 A per cell, so a 48V bank needs a 120 A charger and a 72V bank needs a 180 A charger.
    • Cell-level specific energy is 1,800 Wh ÷ 48.5 kg = 37.1 Wh/kg for the 6-EVF-150, against 38.1 Wh/kg for the 6-EVF-100 — the larger case is slightly less dense.
    • Cycle life of 350–600 cycles applies at 50–80% depth of discharge; running deeper invalidates the headline figure and must be discussed with the supplier.
    • Design life is 2–5 years. The 20-year figure that circulates in the industry belongs to 2V tubular cells, not to a 12V VRLA block.

    §1 — 12V 150Ah Battery Specifications

    Every value below is taken from the manufacturer model page. The derived rows show their formulas so a buyer can re-derive them independently.

    Specification6-EVF-1506-EVF-1206-EVF-1006-EVF-806-EVF-60Source
    Nominal voltage12V12V12V12V12VModel page
    Rated capacity150 Ah120 Ah100 Ah80 Ah60 AhModel page
    Discharge rate basisC3 (3 h)C3C3C3C3Model page
    Dimensions L × W × H483 × 170 × 240 mm407 × 170 × 240 mm330 × 170 × 218 mm259 × 170 × 218 mm258 × 170 × 160 mmModel page
    Weight48.5 ± 0.2 kg40 ± 0.2 kg31.5 ± 0.2 kg25.7 ± 0.2 kg18.8 ± 0.2 kgModel page
    Terminalφ20-M8φ20-M8φ20-M8φ16-M6φ14-M6Model page
    Float charge voltage13.5 V13.5 V13.5 V13.5 V13.5 VModel page
    Equalisation voltage14.1 V14.1 V14.1 V14.1 V14.1 VModel page
    Maximum charge current30.0 A24.0 A20.0 A16.0 A12.0 AModel page
    Cycle life350–600 cycles (DoD 50–80 %)350–600 cycles350–600 cycles350–600 cycles350–600 cyclesModel page
    Cut-off voltage1.75 V/cell1.75 V/cell1.75 V/cell1.75 V/cell1.75 V/cellModel page
    Self-discharge≤3 %/month at 25 °C≤3 %/month≤3 %/month≤3 %/month≤3 %/monthModel page
    Working temperature−15 °C to 50 °C−15 °C to 50 °C−15 °C to 50 °C−15 °C to 50 °C−15 °C to 50 °CModel page
    Design life2–5 years2–5 years2–5 years2–5 years2–5 yearsModel page
    Energy per cell12 V × 150 Ah = 1,800 Wh12 V × 120 Ah = 1,440 Wh12 V × 100 Ah = 1,200 Wh12 V × 80 Ah = 960 Wh12 V × 60 Ah = 720 WhArithmetic
    Cell specific energy1,800 Wh ÷ 48.5 kg = 37.1 Wh/kg1,440 Wh ÷ 40 kg = 36.0 Wh/kg1,200 Wh ÷ 31.5 kg = 38.1 Wh/kg960 Wh ÷ 25.7 kg = 37.4 Wh/kg720 Wh ÷ 18.8 kg = 38.3 Wh/kgArithmetic

    Note the shape of the table. The case grows in length as capacity rises — 483 mm for the 6-EVF-150 against 258 mm for the 6-EVF-60 — but width stays at 170 mm across the 100 Ah, 120 Ah and 150 Ah cells. That means the three largest cells share a tray width while a 60 Ah cell does not, and it is the reason the 6-EVF-150 is usually installed on a bank rack rather than in a vehicle tray.

    §2 — The Pain

    Three recurring failures sit behind most of the returns on 12V 150Ah orders, and each one traces back to an incomplete specification at the point of purchase.

    The first is capacity quoted without a rate. A block marked “150 Ah” tells a buyer nothing about the discharge rate behind the figure. At C3 the cell delivers 150 Ah; at C10 it delivers less, and the same cell behaves differently again when the duty cycle is one deep discharge a month. A quotation that omits the rate cannot be compared with another quotation, and the comparison is usually made in the wrong direction — the cheaper cell appears to be the better one when it is simply a smaller cell.

    The second is the charger. A 48V bank of four 12V 150Ah cells accepts 4 × 30.0 A = 120 A. A charger sized at 60 A will charge the bank without tripping anything, but it will take roughly twice as long: 150 Ah ÷ 30.0 A = 5 hours is the theoretical minimum at the published current, while 150 Ah ÷ 15.0 A = 10 hours is the same bank on a half-size charger. In a solar site without a generator, that difference is the difference between reaching float before dusk and not.

    The third is vented space. At 483 × 170 × 240 mm and 48.5 kg, four of these cells occupy roughly 0.19 cubic metres and 194.0 kg of rack weight. Cabinets designed for the 6-EVF-100 (330 × 170 × 218 mm) are 153 mm too short per cell. Nothing in the product changes; the cabinet does.

    Underneath those three sits a sourcing problem. Buyers in Lagos, Mombasa, Chennai, Cairo and São Paulo frequently receive quotations that say only “150 Ah VRLA, 12V, deep cycle” with no case reference, no weight and no charge setpoints — which makes the order impossible to re-order, impossible to compare and impossible to defend when the container arrives.

    §3 — The Choice

    Five capacities are available inside the EVF series at 12V. The table below converts each into a 48V bank so that the comparison happens in the units the installer actually works in.

    48V bank buildCells usedBank voltageBank energyBank weightBank specific energyCharger outputSource
    Four 6-EVF-1504 × 12V 150Ah12 V × 4 = 48 V48 V × 150 Ah = 7,200 Wh4 × 48.5 kg = 194.0 kg7,200 Wh ÷ 194.0 kg = 37.1 Wh/kg4 × 30.0 A = 120 AArithmetic
    Four 6-EVF-1204 × 12V 120Ah12 V × 4 = 48 V48 V × 120 Ah = 5,760 Wh4 × 40 kg = 160.0 kg5,760 Wh ÷ 160.0 kg = 36.0 Wh/kg4 × 24.0 A = 96.0 AArithmetic
    Four 6-EVF-1004 × 12V 100Ah12 V × 4 = 48 V48 V × 100 Ah = 4,800 Wh4 × 31.5 kg = 126.0 kg4,800 Wh ÷ 126.0 kg = 38.1 Wh/kg4 × 20.0 A = 80.0 AArithmetic
    Four 6-EVF-804 × 12V 80Ah12 V × 4 = 48 V48 V × 80 Ah = 3,840 Wh4 × 25.7 kg = 102.8 kg3,840 Wh ÷ 102.8 kg = 37.4 Wh/kg4 × 16.0 A = 64.0 AArithmetic
    Four 6-EVF-604 × 12V 60Ah12 V × 4 = 48 V48 V × 60 Ah = 2,880 Wh4 × 18.8 kg = 75.2 kg2,880 Wh ÷ 75.2 kg = 38.3 Wh/kg4 × 12.0 A = 48.0 AArithmetic

    For 72V installations — common in telecom DC plants, larger solar systems and heavy traction — the same cell is simply multiplied out: 12 V × 6 = 72 V, 72 V × 150 Ah = 10,800 Wh, 6 × 48.5 kg = 291.0 kg, and a charger of 6 × 30.0 A = 180 A.

    The choice reads as a shortlist rather than a ranking, because the right answer depends on which constraint binds.

    If runtime is the constraint — a deep-cycle solar site, a telecom site with a long autonomy window, a warehouse AGV fleet that charges once per shift — the 6-EVF-150 is the correct cell, and the 7,200 Wh bank is the unit that makes the autonomy calculation work. The published 6-EVF-150 model page carries the full figure set.

    If floor loading is the constraint, the 6-EVF-120 is usually the answer: 160.0 kg against 194.0 kg per bank, at 5,760 Wh rather than 7,200 Wh. That is a 34.0 kg saving per bank, and on a raised floor in a Rotterdam or Hamburg plant the structural limit is frequently the real limit. The 6-EVF-120 model page publishes the 407 × 170 × 240 mm case and 40 ± 0.2 kg.

    If the cabinet is already built for a shorter cell, the 6-EVF-100 fits inside 330 × 170 × 218 mm and still delivers 38.1 Wh/kg, the best bank specific energy of the five.

    The complete 12V VRLA range, covering the 6-DZF, 6-DMF and 6-EVF series from 12 Ah to 150 Ah, is indexed on the CHISEN 12V VRLA product page.

    §4 — The Framework

    Seven checks separate a workable 12V 150Ah order from a problematic one.

    1. Pin the discharge rate. Require the capacity to be stated at C3, and require the same rate basis from every supplier you are comparing. If a supplier quotes at C10 and another at C3, convert before comparing.

    2. Write the charge setpoints into the order. 13.5 V float and 14.1 V equalisation for the block. Across the six cells of a 12V unit that is 2.25 V per cell floating and 2.35 V per cell in equalisation. Confirm your charger controller can hold both, and confirm the equalisation interval — a controller that never equalises will sulphate a deep-cycle bank well before the published cycle count is reached.

    3. Size the charger from the published charge current, not from habit. 30.0 A per cell for the 6-EVF-150 means a 120 A charger for a 48V bank and 180 A for a 72V bank. Halving the charger doubles the recharge window to 150 Ah ÷ 15.0 A = 10 hours.

    4. Fix the depth-of-discharge envelope. The 350–600 cycle rating is published at 50–80% depth of discharge. A telecom site that runs to 90% on a bad month is outside that window, and the supplier should say so on the datasheet.

    5. Confirm the case and the cabinet before the order is placed. 483 × 170 × 240 mm and 48.5 kg are the numbers to take to the rack designer. Also confirm the terminal: φ20-M8 on the 6-EVF-150 and 6-EVF-120, but φ16-M6 on the 6-EVF-80 and φ14-M6 on the 6-EVF-60, so the cable lug changes with the capacity step.

    6. Confirm the thermal envelope in the installed location. The published working range is −15 °C to 50 °C and capacity is quoted at 25 °C. A containerised cabinet in Jebel Ali or Chennai can exceed 50 °C in the upper half, and a bank in a Bangkok or Durban machine room needs forced ventilation, not just a published range.

    7. Agree the arrival test. For shipments landing at Santos, Jebel Ali, Lagos, Port Said or Mombasa, write the acceptance procedure into the contract: a sample capacity check at C3, a float voltage check across the bank, and a named laboratory for re-inspection if a sample fails.

    §5 — The Trust

    The 6-EVF-150 and the rest of the EVF series are produced on VRLA lines inside a manufacturer that operates 8 production bases with an annual capacity of 70 million kVAh, under a quality management system certified to ISO 9001, with ISO 14001 for the environmental system, and CE, UL and IEC conformity for the destination markets. Every figure quoted in this article is taken from the individual model page rather than from a catalogue summary, and the full range is maintained on the CHISEN 12V VRLA index.

    Two distinctions matter to a buyer who is being asked to pay for assurance.

    First, a certificate covers a management system, a scope and a date. ISO 9001 confirms that the plant runs documented procedures and acts on non-conformity; it does not confirm that a particular block holds 150 Ah. That is the job of the published capacity figure, the type test and the acceptance test. Ask for the certificate number, the scope statement, the registered address and the validity dates, then verify the cell separately.

    Second, and more commercially important, the difference between a published specification and a marketing line determines whether a tender can be run properly. “12V 150Ah, heavy duty, best quality” cannot be compared across three suppliers and cannot be re-ordered in two years. “6-EVF-150, 150 Ah at C3, 483 × 170 × 240 mm, 48.5 ± 0.2 kg, float 13.5 V, equalisation 14.1 V, 30.0 A maximum charge current” can be compared line by line, engineered into a charger setting, and defended at the goods-in dock.

    For buyers working through a distributor, ask for the manufacturer’s model page URL and the batch reference on the packing list. Both can be verified before the container is opened, and together they remove the most common source of dispute in deep-cycle VRLA supply.

    §6 — FAQ

    Q1. How many 12V 150Ah batteries make a 48V bank? Four. 12 V × 4 = 48 V, and the bank capacity is 48 V × 150 Ah = 7,200 Wh. The four cells share the same charge current, so the bank needs a charger of 4 × 30.0 A = 120 A, and the bank weight is 4 × 48.5 kg = 194.0 kg. Always match cells of the same model and the same age in a series bank.

    Q2. What is the difference between a 12V 150Ah AGM battery and a 12V 150Ah gel battery? Both are 12V VRLA products with the same nominal voltage and comparable cycle ratings, but they use different electrolyte and different plate construction, which changes gas recombination behaviour, thermal profile and the charge regime they tolerate. For a telecom DC plant, a solar site or a deep-cycle AGV application, the deciding factor is the published specification of the cell you are actually offered, not the label. Ask for the model code, the published capacity at C3, the float and equalisation voltages and the cycle rating at your depth of discharge, then compare those figures directly.

    Q3. How long does it take to charge a 48V bank of 12V 150Ah batteries? At the published maximum charge current of 30.0 A per cell, the theoretical minimum is 150 Ah ÷ 30.0 A = 5 hours. In practice, absorption and equalisation add two to four hours, so a realistic figure for a full charge from a deep discharge is seven to nine hours on a 120 A charger. A 60 A charger stretches the bulk stage to 150 Ah ÷ 15.0 A = 10 hours, which in a solar-only site can push the bank past the useful part of the day.

    Q4. Can I run a 72V bank with 12V 150Ah batteries? Yes. Six cells in series give 12 V × 6 = 72 V, 72 V × 150 Ah = 10,800 Wh, a bank weight of 6 × 48.5 kg = 291.0 kg, and a charger requirement of 6 × 30.0 A = 180 A. The float and equalisation setpoints remain 13.5 V and 14.1 V per 12V unit, which is 2.25 V and 2.35 V per cell. Because the series string is longer, cell matching matters more — require the supplier to supply cells from one production batch.

    Q5. How many cycles will a 12V 150Ah deep cycle battery give? The published figure is 350–600 cycles at 50–80% depth of discharge. The spread is not a tolerance on one number; it reflects discharge rate, temperature and the depth of discharge you actually use. Running consistently at the shallow end of that window gives more cycles than the lower figure; running deep or hot gives fewer. Ask the supplier for the cycle rating at your specific depth of discharge and your site temperature rather than accepting the headline range.

    Q6. What is the difference between the 6-EVF-150 and the 6-EVF-120? Capacity, case length and weight. The 6-EVF-150 publishes 483 × 170 × 240 mm and 48.5 ± 0.2 kg for 150 Ah; the 6-EVF-120 publishes 407 × 170 × 240 mm and 40 ± 0.2 kg for 120 Ah. Both share the 170 mm width, the φ20-M8 terminal, the 13.5 V float and 14.1 V equalisation setpoints, so a rack built for either can take the other provided the length and load rating are checked. A 48V bank of four 6-EVF-120 cells weighs 160.0 kg against 194.0 kg for four 6-EVF-150 cells.

    Q7. What is the correct float voltage for a 12V 150Ah battery? 13.5 V for the block, which is 2.25 V per cell across the six cells, with equalisation at 14.1 V, or 2.35 V per cell. Do not set the charger to a generic lead-acid default of 14.4 V; on a VRLA block that is 2.40 V per cell and it will shorten service life without adding usable capacity. If the bank sits in a hot climate, use the charger’s temperature-compensation input rather than changing the base setpoint.

    Q8. How should a 12V 150Ah battery be shipped and received? VRLA cells are shipped at a partial state of charge and self-discharge at no more than 3 % per month at 25 °C, so a long sea voyage reduces what you receive. Record the open-circuit voltage of every block on arrival, keep the blocks at 20–25 °C until they are put on charge, and put them on float promptly. For shipments to Santos, Jebel Ali, Lagos or Port Said, specify in the contract that the batch reference and the model page revision must appear on the packing list, and agree the sample capacity check at C3 before the balance is released.

    Expert Summary

    A 12V 150Ah battery is fully specified in public: 150 Ah at C3, 483 × 170 × 240 mm, 48.5 ± 0.2 kg, 13.5 V float, 14.1 V equalisation, 30.0 A maximum charge current, 350–600 cycles at 50–80% depth of discharge, 2–5 years design life, −15 °C to 50 °C working range. Four cells give a 48V bank of 7,200 Wh at 194.0 kg; six cells give a 72V bank of 10,800 Wh at 291.0 kg.

    The engineering consequence of that figure set is short. The charger is sized from the published charge current — 120 A for a 48V bank, 180 A for 72V — and the depth-of-discharge window must be agreed in writing because the cycle rating is only valid inside it. Everything else in the ordering process is administrative, and it is the administrative part that is usually missing.

    For importers serving Lagos, Jebel Ali, Chennai, Santos, Durban or Hamburg, the sequence that works is the same: fix the published specification first, then let suppliers compete against it. The figure set in §1 is enough to run that comparison in a single afternoon, and it is enough to hold the winner to it at the port.

    Contact CHISEN

    Send the duty cycle, the required autonomy, the cabinet or rack dimensions and the quantity to the CHISEN export desk, and you will receive a quotation built on the published specification, the datasheet and the current lead time.

    • Email: jack@chisen.cn or sales@chisen.cn
    • WhatsApp: +86 131 6622 6999
    • 12V VRLA product index: https://www.chisen.cn/en/LeadacidBattery/EVF.html
    • 6-EVF-150 model page: https://www.chisen.cn/en/6-EVF-150/12V150Ah.html
    • 6-EVF-120 model page: https://www.chisen.cn/en/6-EVF-120/12V120Ah.html

    Related reading on the CHISEN knowledge centre: deep-cycle charge setpoints, VRLA bank layout and cell matching, and pack-sizing method for solar, telecom and AGV duty.

    CHISEN Battery — lead-acid cells and systems for telecom, solar, UPS, AGV and traction applications. 8 production bases, 70 million kVAh annual capacity, ISO 9001 and ISO 14001 certified.

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