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3-EVF-200 6V200Ah AGM Battery: 48V Pack Sizing for Golf Carts, Sightseeing Vehicles and AGVs

Reading time: 16 minutes | For: electric vehicle OEMs, golf-course and resort fleet managers, airport and port ground-support procurement teams, AGV integrators, and battery distributors serving India, Southeast Asia, the Gulf, Latin America and Africa

Answer First

The 3-EVF-200 6V200Ah is a 6-volt, 200 amp-hour sealed valve-regulated AGM lead-acid block designed for mid-to-large electric road vehicles: 4-8 seat sightseeing vehicles, golf carts, 1-3 ton electric forklifts and stackers, floor scrubbers and sweepers, AGV robots and small electric boats. It is the 6 V member of the EVF traction range, and its 200 Ah rating is a 3-hour rate at a 1.75 V per cell cutoff — not a 20-hour figure.

Five numbers decide the procurement:

200 Ah at C3 (3-hour rate), cutoff 1.75 V per cell. A 20-hour rating for the same block is materially lower, and sellers who quote one and compare it against the other create a battery that underperforms in the middle of a shift.
260 x 180 x 270 mm, 275 mm over the terminals, 34 kg per unit. Eight units in series make a 48 V pack that weighs 272 kg.
40 A maximum charging current and float 6.75 V / equalise 7.05 V for the 6 V block. The charger and the controller profile must match this voltage band exactly.
350-600 cycles at 50-80% depth of discharge, with a 2-5 year design life and a -15 °C to +50 °C working window.
Sealed construction with no water or acid refill, which means no service visits, but also means the end of life arrives as a block replacement rather than a gradual capacity loss you can measure in the field.

The honest caveat: the 3-EVF-200 6V200Ah is a traction cell with a stationary charging profile (6.75 V float, 7.05 V equalise, 40 A). If your vehicle runs a daily deep-discharge cycle with a BMS-controlled lithium pack, the comparison changes; §3 shows exactly where the boundary sits.

Key Takeaways

The rating basis is the whole argument. 3-EVF-200 6V200Ah means 200 Ah at C3 with a 1.75 V per cell cutoff. Insist on the C3 definition in the warranty, because a 20-hour seller figure for the same case is a different product.
Pack arithmetic decides the configuration, not habit. Eight 3-EVF-200 units give a 48 V bus, 10-12 units give 60-72 V for heavier forklift and stacker classes, and 8-16 units cover the 48-96 V band. Each step up in voltage adds units, weight and terminals.
Energy per pack is the number to compare. Eight 3-EVF-200 units in a 48 V pack deliver 9.6 kWh nominal (8 x 6 V x 200 Ah); a smaller block in the same voltage class can be beaten on energy while using the same unit count.
Charging is a hard limit, not a recommendation. 40 A per unit means an eight-unit 48 V pack wants a charger in the 320 A class, with a 6.75 V float and 7.05 V equalise stage controlled to the vehicle profile.
Temperature and storage discipline matter more than in warmer markets. The published window is -15 °C to +50 °C, and a battery shipped through a hot port or stored through a dry season needs the 12-hour initial charge before it goes into service.

§1 — 3-EVF-200 6V200Ah Quick Specifications Table

The published 3-EVF-200 6V200Ah data sheet is the basis for every number below. The full factory page for this block is at the 3-EVF-200 product page.

Parameter	Published value for 3-EVF-200
Model	3-EVF-200
Nominal voltage	6 V
Capacity	200 Ah at the 3-hour discharge rate (C3), cutoff 1.75 V/cell
Dimensions (L x W x H)	260 x 180 x 270 mm
Total height over terminals	275 mm
Weight	34 kg (+/- 0.2 kg)
Terminal	phi20-M8
Technology	Valve-regulated lead-acid, AGM (VRLA)
Cycle life	350-600 cycles at 50-80% depth of discharge
Float voltage	6.75 V
Equalise charge voltage	7.05 V
Maximum charging current	40.0 A
Working temperature	-15 °C to +50 °C
Design lifespan	2-5 years
Maintenance	Maintenance-free; no water or acid refilling
Initial charge	New or long-idle batteries require an initial charge of not less than 12 hours
System configuration	8 units in series for 48 V; 10-12 units for 60-72 V; 8-16 units for 48-96 V
Typical applications	Electric sightseeing vehicles (4-8 seats), golf carts, electric forklifts and stackers (1-3 ton), floor scrubbers and sweepers, AGV robots, electric boats

§2 — The Pain

The failure mode in this category is not dramatic. It is a battery that arrives correctly, passes a workshop charge test, and then leaves a vehicle short of range in the middle of a working day. The causes are always the same three, and all three start with a specification that nobody pinned down.

The rating basis is assumed rather than stated. A buyer asks for “6 volt 200 amp-hour” and receives a block that satisfies 200 Ah at the 20-hour rate. That block is a different product from the 3-EVF-200 6V200Ah, which delivers 200 Ah at C3. On a vehicle that pulls a high current for a few hours per shift, the 20-hour-rated block looks fine on the datasheet and then shows a shorter working window than the operator expects. The procurement problem is that nothing in the purchase order says which basis applies, so nobody can hold the supplier to a number.

The charge controller is specified separately from the battery. A 6 V block floats at 6.75 V and equalises at 7.05 V. A charger programmed for a different chemistry or a different voltage band will trickle at the wrong voltage, will not complete an equalise stage after a deep discharge, and will age the block faster than the published cycle life assumes. For an unattended or leased fleet this happens quietly, because the vehicle still runs.

Pack configuration is inherited from a previous model. Eight units at 6 V and four units at 12 V both make a 48 V pack, and both are quoted as “48 V”. The unit count changes the mechanical envelope, the interconnect count, the service procedure and the failure surface: eight units means eight sets of terminals and eight potential points of thermal stress.

There is a fourth, quieter problem. Storage. A 6 V block that has been in a container at Jebel Ali or Santos through a hot season, or that has sat in a distributor warehouse in Dubai, arrives with a partial state of charge and a surface charge that looks like a full battery. The published instruction is not negotiable: the first charge after transit or after long idle storage should run not less than 12 hours before the vehicle goes into service.

§3 — The Choice

3-EVF-200 6V200Ah is the right block when the vehicle runs a 48 V bus, the duty is deep daily discharge, and the site has no maintenance capability. The pack arithmetic is published, and so is everything you need to check it against:

Pack configuration	Units	Bus voltage	Capacity basis	Nominal energy (arithmetic)	Pack weight (arithmetic)	Charge current (arithmetic)	Where it fits
48 V pack	8	48 V	200 Ah at C3	8 x 6 V x 200 Ah = 9.6 kWh	8 x 34 kg = 272 kg	8 x 40 A = 320 A	Golf carts, 4-8 seat sightseeing vehicles, scrubbers
60 V pack	10	60 V	200 Ah at C3	10 x 6 V x 200 Ah = 12.0 kWh	10 x 34 kg = 340 kg	10 x 40 A = 400 A	Light forklift and stacker classes
72 V pack	12	72 V	200 Ah at C3	12 x 6 V x 200 Ah = 14.4 kWh	12 x 34 kg = 408 kg	12 x 40 A = 480 A	1-3 ton electric forklifts and stackers
96 V pack	16	96 V	200 Ah at C3	16 x 6 V x 200 Ah = 19.2 kWh	16 x 34 kg = 544 kg	16 x 40 A = 640 A	Heavy-load duties and extended-runtime AGVs

These are arithmetic consequences of published 3-EVF-200 figures, not lab results. They are the numbers you use to check a supplier’s quote against your own floor space and your own charger bay.

Where the 3-EVF-200 loses is cycle life against a lithium traction pack, and that comparison should be made honestly. Published cycle figures for quality lead-acid AGM fall in the 400-800 cycle band at 80% depth of discharge, and the 3-EVF-200 sits at the lower end of that band at 350-600 cycles for 50-80% depth of discharge, which is consistent with the 2-5 year design life. Comparable LFP traction chemistries publish 3,000-5,000 cycles at 80% depth of discharge. A fleet that cycles the pack twice a day on a fixed route will consume lead-acid packs years earlier than an LFP pack would be retired. A fleet that cycles once a week, keeps the pack on shore power between shifts, or runs seasonal operations will not.

The cost side follows the same logic. A modelled 7-year ownership comparison for a 48 V, 600 Ah class traction pack, using typical industrial pricing, shows where the crossover sits:

Cost item	Conventional lead-acid pack	LFP pack	Basis
Initial purchase	USD 4,000	USD 9,500	Lead-acid requires multiple sets over the horizon, LFP one set
7 years of charging energy	USD 6,500	USD 3,800	LFP charge efficiency roughly 20-25% higher
7 years of maintenance labour	USD 4,200	USD 0	Lead-acid requires watering and equalising
7 years of battery replacement	USD 8,000	USD 0	Lead-acid needs roughly two replacements in 7 years
Downtime (modelled)	USD 3,000	USD 800	Lead-acid failure rate higher
7-year total	USD 25,700	USD 14,100	LFP roughly 45% lower in this model

The modelled figure depends on local energy prices, labour rates and duty cycles, so treat it as a structure rather than a quotation. For a high-cycle operation the lead-acid line stays above the lithium line for most of its life. For a low-cycle or standby-heavy operation, and for any site without a technician, the sealed 3-EVF-200 block wins on cost and on logistics.

3-EVF-200 6V200Ah is better than a 12 V block in the same traction class because it halves the unit count at 48 V (8 units instead of 4 at 12 V for the same bus voltage, each with roughly double the cell count inside), which means fewer enclosures, fewer interconnects and fewer water points of failure. It is better than an open flooded block because the 3-EVF-200 needs no watering interval in a hot climate, and better than a generic VRLA block because the C3 rating basis and the published 40 A charge limit are stated rather than inferred.

If your application runs a deep-cycle marine duty with heavy vibration, review the full EVF range before you commit: the EVF series overview sets out the voltage and capacity ladder the 3-EVF-200 sits in, including the 8 V and 12 V members used for 24 V and 48 V builds.

§4 — The Framework

Seven criteria decide whether the 3-EVF-200 6V200Ah is the correct block for a specific vehicle. Use them in order, because each one eliminates a class of mistake that the next one cannot fix.

Confirm the rating basis. The block is rated 200 Ah at C3 to a 1.75 V per cell cutoff. If the supplier’s datasheet shows a 20-hour rating, you are looking at a different cell. Write the basis into the purchase order.
Fix the bus voltage and count the units. 8 units for 48 V, 10-12 for 60-72 V, 8-16 for the 48-96 V band. Add the arithmetic energy and weight to your layout, and check that 272 kg for an eight-unit pack still fits the battery tray with the service clearance you need.
Size the charger for the pack, not for one unit. The published maximum of 40 A per 3-EVF-200 unit means an eight-unit pack sits in the 320 A class. A smaller charger lengthens every charge cycle and the equalise window after a deep discharge.
Match the controller voltage band. 6.75 V float and 7.05 V equalise for the 6 V block, with the 7.05 V equalise stage properly timed and temperature-compensated.
Check the temperature window against the deployment reality. -15 °C to +50 °C covers most sheltered sites in Mumbai, Durban, Ho Chi Minh City and Jakarta; a vehicle parked in direct sun in a non-air-conditioned bay in the Gulf or northern India can exceed the published charge ceiling during an equalise cycle.
Plan the initial charge. Not less than 12 hours for a new block or one that has been stored or shipped long. This applies to every block that has crossed an ocean in a container through Mombasa, Santos, Port Said or Jebel Ali.
Standardise on one block across the fleet. Mixing capacities inside a pack set is the most common cause of the early failures the manufacturer never sees. If you are standardising an AGV or forklift fleet, the AGV battery programme and the AGM and front-terminal range are the reference for the rest of the pack.

§5 — The Trust

The 3-EVF-200 6V200Ah is a straightforward industrial block, and straightforward products are exactly where procurement shortcuts accumulate. Before you sign, work through this list.

Ask for the test basis, not the headline number. A published “350-600 cycles” figure for the 3-EVF-200 means cycles at 50-80% depth of discharge under a defined test profile. Ask which depth of discharge the lower and upper figures refer to, at what cutoff voltage, and at what temperature. A supplier who cannot answer that in one email is telling you something useful.

Confirm the charge limit in writing. 40 A is a published maximum for the block. If your charger program exceeds it, the warranty position is yours, not the supplier’s. Any claim that a charger can be set to 0.3C on this block should be checked against the datasheet before it reaches the vehicle.

Do not accept a capacity figure without the rate. A “200 Ah” quoted without C3 is a 200 Ah claim at an unknown rate. Ask for the discharge curve or the test certificate.

Verify the physical tolerances. 34 kg +/- 0.2 kg and 260 x 180 x 270 mm are published. A tolerance of more than a few millimetres across a fleet makes tray machining and connector alignment inconsistent, and inconsistent trays generate vibration failures on scrubbers and AGVs.

Check the storage and shipping plan. Sealed AGM blocks ship more simply than flooded cells, but they still arrive with a partial state of charge. A supplier who documents the 12-hour initial charge, the storage temperature and the shipping interval is a supplier who has shipped these before.

Ask who handles the warranty claim in your market. A 2-5 year design life is only worth what the local claim path is worth. For distributors in Brazil, Poland, Turkey, South Africa and the Gulf, this is the single most important line in the agreement.

Do not accept a cell that arrives wet. A sealed 3-EVF-200 block has no vent to dry out and no liquid to top up. Any sign of corrosion on the terminal, or a swollen case, means the block was damaged in transit or stored at a temperature outside the published range. Reject it at the door.

§6 — FAQ

Q1. What does 200 Ah mean on the 3-EVF-200 6V200Ah, and why does the rating basis matter? It means 200 Ah at the 3-hour discharge rate with a 1.75 V per cell cutoff. A cell rated 200 Ah at the 20-hour rate gives a smaller working window in the 1-4 hour discharge pattern typical of a traction vehicle, so the two figures are not interchangeable. Ask the supplier to state the basis in the quotation.

Q2. How many 3-EVF-200 blocks make a 48 V pack, and how much does it weigh? Eight units in series. Nominal energy is 8 x 6 V x 200 Ah = 9.6 kWh and pack weight is 8 x 34 kg = 272 kg, both straight arithmetic from published figures. The published configuration band also covers 10-12 units for 60-72 V and 8-16 units for the 48-96 V range.

Q3. What charging current does the pack need? The published maximum is 40 A per block, so an eight-unit 48 V pack sits in the 320 A class and a twelve-unit 72 V pack in the 480 A class. Float is 6.75 V for the 6 V block and equalise is 7.05 V. Undersizing the charger lengthens the charge cycle and degrades the equalise stage after a deep discharge.

Q4. Can the 3-EVF-200 6V200Ah be used for a golf cart, a forklift and an AGV with the same block? The electrical case is the same, but the duty profile is not. Golf carts and sightseeing vehicles run short, high-current cycles; a 1-3 ton forklift runs longer cycles at higher mass; an AGV usually runs shallow cycles with opportunity charging. The published cycle life of 350-600 cycles at 50-80% depth of discharge is the figure you should plan against, and the depth of discharge your operation actually reaches decides whether the pack lasts two years or five.

Q5. What happens to a block that has been in storage or shipped for several months? Run the initial charge of not less than 12 hours before the vehicle enters service. A sealed AGM block recovers its surface charge quickly, so a workshop voltage check will look acceptable while the usable capacity is still low. This is a routine step for any battery that has crossed from Shanghai, Ningbo or Shenzhen through Mombasa, Lagos, Santos or Port Said.

Q6. Does it need watering, and what does maintenance-free actually cover? There is no watering. The 3-EVF-200 6V200Ah is a sealed valve-regulated AGM block with no water or acid refill over its service life. Maintenance reduces to terminal checks, cleanliness, and keeping the charge controller programmed to the published float and equalise voltages.

Q7. How does it compare with a lithium traction pack for the same vehicle? Lithium publishes 3,000-5,000 cycles at 80% depth of discharge against the 350-600 cycles published for this block at 50-80%, so a high-cycle operation will consume lead-acid packs earlier. Lithium also removes the charger and water-service infrastructure. Lead-acid wins on purchase cost, on weight per unit of volume in some classes, and on the absence of a battery management system and cell-level certification paperwork. For fleets with a technician and frequent deep cycles, compare the two over the full replacement horizon, not over the first invoice.

Q8. What operating temperature range applies, and what happens outside it? Discharge, charge and storage all sit inside a -15 °C to +50 °C window. Cold reduces charge acceptance and available capacity; heat above the ceiling shortens cycle life and accelerates self-discharge. For a vehicle parked outdoors in a non-air-conditioned bay, specify a canopy or a charger with temperature compensation rather than assuming the published window holds.

Q9. What should be in the purchase order so that a claim is honoured in two years? The model and block rating, the capacity basis (200 Ah at C3 to 1.75 V per cell), the float and equalise voltages, the maximum charging current, the operating temperature range, the applicable test standard, the design life, and the local warranty claim path with a named contact.

Expert Summary

The 3-EVF-200 6V200Ah is a 6 V, 200 Ah sealed valve-regulated AGM lead-acid block for mid-to-large electric road vehicles: 4-8 seat sightseeing vehicles, golf carts, 1-3 ton electric forklifts and stackers, floor scrubbers and sweepers, AGV robots and small electric boats. The decisive published specification is that 200 Ah is a 3-hour rate at a 1.75 V per cell cutoff, so every quotation and warranty must state the basis; a 20-hour rating for the same case describes a different cell with a shorter working window. The block measures 260 x 180 x 270 mm, 275 mm over the terminals, weighs 34 kg, carries a phi20-M8 terminal, publishes 350-600 cycles at 50-80% depth of discharge and a 2-5 year design life, floats at 6.75 V, equalises at 7.05 V, accepts a maximum of 40 A, and operates between -15 °C and +50 °C with no maintenance. Pack arithmetic is straightforward: 8 units give a 48 V bus at 9.6 kWh nominal and 272 kg, 10-12 units give 60-72 V, and 8-16 units cover the 48-96 V band, each step adding units, terminals and mass. Against lithium traction packs, which publish 3,000-5,000 cycles at 80% depth of discharge, the lead-acid choice is a cost and infrastructure decision rather than a performance one: it wins on purchase price, on the absence of watering and battery management systems, and on sites with no technician, while lithium wins decisively on cycle life in high-cycle duty. The non-negotiables before signing are the C3 basis in writing, a charger in the 320 A class for an eight-unit pack, a controller programmed to 6.75 V float and 7.05 V equalise, a temperature check against the published ceiling, a 12-hour initial charge for any new or long-stored block, and a documented local warranty path.

Contact CHISEN — 24-Hour Response

CHISEN replies to technical and commercial enquiries within 24 hours, and delivers a sizing sheet and quotation against your actual duty data.

Send us the information below and we will return a written recommendation with the published data for the block and the pack configuration that matches it:

Vehicle type and duty cycle (how many cycles per day, depth of discharge, shift pattern)
Bus voltage and pack configuration, or the duty you want to size
Ambient temperature range at the deployment site
Charger type, voltage and available output current
Annual volume and destination port for the first shipment

Email: sales@chisen.cn WhatsApp: +86 131 6622 6999 Call: +86 131 6622 6999

Technical enquiries, project drawings and tender documents: leadacidbattery.cn

Related CHISEN Buyer Guides

October 23, 2026

OPzS2-420 2V420Ah Flooded Tubular Battery: Manned-Room versus Unattended Site Selection

Reading time: 17 minutes | For: telecom power engineers, railway signalling procurement, data-centre facility teams, utility and marine project buyers, and battery distributors serving South Asia, the Gulf, Africa and Latin America

Answer First

The OPzS2-420 2V420Ah is a 2-volt, 420 amp-hour flooded tubular-plate lead-acid cell — die-cast low-antimony positive plates with liquid dilute sulphuric acid electrolyte in a transparent container. It is the classic manned-room stationary cell: cheap per kWh, serviceable, and completely dependent on someone being there to refill water and read the electrolyte level. Its published rating is 420 Ah at the 10-hour rate (C10), discharged to 1.80 V per cell.

Five numbers decide the procurement:

420 Ah at C10 to 1.80 V per cell. The 20-hour rate is not published, so a quotation quoting “420 Ah at 20 hours” is quoting a different rating basis.
145 x 206 x 471 mm, 525 mm over the terminals. The datasheet publishes the weight as 24.0 kg without electrolyte and 32.0 kg with electrolyte, with 8.0 kg of acid.
Vertical installation only. Electrolyte leaks if the cell is laid horizontal, which changes the rack design, the aisle width and the service procedure for the entire string.
Water refill every 3-6 months at a manned site, against a published float design life of 20+ years at 20 °C.
Float 2.23 V per cell, equalise 2.35 V per cell (2.40 V for solar and wind regulation), maximum charge current 84 A, internal resistance 0.56 mΩ, self-discharge 3% per month, discharge rated -25 to +65 °C and charge -20 to +65 °C.

The honest caveat: the OPzS2-420 2V420Ah is the right answer when a person visits the battery room on a schedule and the site has a service contract. It is the wrong answer for an unattended telecom site, an island station or a border post where the next visit is a year away. §3 makes that comparison with published numbers on both sides.

Key Takeaways

Manned room or unmanned site is the first question, not price. The flooded OPzS2-420 2V420Ah costs less and can be serviced by hand; the sealed gel equivalent costs more and needs no service visit for its whole life.
Vertical-only installation is a design constraint. 145 mm of cell width is fine; the 470 mm body plus terminals and the upright requirement determine the rack pitch and the aisle.
String arithmetic: 24 cells give 48 V at 20.16 kWh, 54 give 108 V at 45.36 kWh, 108 give 216 V at 90.72 kWh, and the charger class runs from 96.8 kW to 766 kW at the published 84 A per cell.
The refill interval is the real line item. Three to six months of watering, on a 24 or 54 cell string, in a hot climate, is a permanent operational cost that a sealed cell removes entirely.
Never buy without the weight. The published page does not carry the weight for this model, and the rack, the floor and the lifting method all depend on it.

§1 — OPzS2-420 2V420Ah Quick Specifications Table

Every value below is taken from the published CHISEN data sheet for the OPzS2-420 2V420Ah. The factory page carries the same data with drawings and the maintenance instructions.

Parameter	Published value for OPzS2-420
Model	OPzS2-420
Series / technology	Tubular flooded: die-cast tubular positive plate (low-antimony Pb-Sb), liquid dilute sulphuric acid electrolyte at 1.24 +/- 0.01 g/cm³ fully charged, transparent SAN container with vent plug
Nominal voltage	2 V (DC)
Capacity	420 Ah at C10 (10-hour rate, discharged to 1.80 V/cell)
Dimensions (L x W x H)	145 x 206 x 471 mm
Total height over terminals	525 mm
Weight	Not published on the factory page – request the datasheet value before finalising rack and floor-loading design
Terminal	Phi20-M8, torque 10-12 N.m
Cycle life	1,500-2,500 cycles at 80% DOD at 25 °C
Float voltage	2.23 V/cell at 25 °C, compensation -3 mV/°C/cell
Cycle / equalise voltage	2.35 V/cell at 25 °C (2.40 V for solar and wind regulation), compensation -3 mV/°C/cell
Maximum charge current	84 A
Internal resistance	0.56 mOhm fully charged at 25 °C
Short-circuit current	3,500 A
Self-discharge	3% per month; storable 9-12 months without recharging at 20-25 °C
Operating temperature	Discharge -25 to +65 °C; charge -20 to +65 °C; storage -25 to +45 °C
Float design life	20+ years (20+ years at 20 °C)
Installation orientation	Vertical only – electrolyte leaks if tilted or laid horizontal
Maintenance	Water refill (distilled or deionised) every 3-6 months; liquid level and plate condition visible through the transparent container
Standards	IEC 60896-11, DIN 40736-1, GB/T 19638.2, Eurobat Long Life, BS 6290 Part 4 / UL 1989
Applications	Telecom base stations (especially manned rooms), PV and wind energy storage, large data-centre UPS above 500 kVA, industrial backup power, emergency lighting, industrial control power, solar street lights, railway signalling, marine applications, medical equipment
String configuration	24 cells = 48 V; 54 cells = 108 V (110 V); 108 cells = 216 V (220 V); 190 cells = 380 V three-phase DC

§2 — The Pain

The flooded tubular cell is a 25-year product with a 25-year service routine attached to it, and the routine is where the cost hides.

The refill interval is treated as an afterthought. Every 3-6 months, someone must enter the battery room, read the electrolyte level, add distilled water, record the reading and check the specific gravity. On a 54-cell OPzS2-420 string that is a recurring site visit, a vehicle, a water container and a technician. The failure is not that the visit is skipped; it is that the visit is skipped twice and the string is found at a lower electrolyte level than the design allows.

The vertical-only rule is discovered after the rack is built. A flooded cell that is laid horizontal leaks. In a retrofit, the existing rack pitch is often shorter than the 525 mm the OPzS2-420 2V420Ah needs over its terminals, and the tempting-looking fix is to lay the cell down temporarily. That decision costs electrolyte, corrosion and a shortened life.

The rating basis is assumed rather than stated. 420 Ah at C10 to 1.80 V per cell is the published figure. A cell quoted at 420 Ah on the 20-hour basis is a different product, and the difference shows up as a shorter backup window in the first year, not as a failure.

The site visit frequency is a design input. A manned telecom room in Mumbai, Chennai, Durban or Cairo is a good home for a flooded cell. An unattended site, an island, a border post or a rail trackside hut is not. The same OPzS2-420 2V420Ah, the same price, two completely different total costs.

The weight is left out of the tender. The factory page does not publish the weight for this model, and the rack, the floor loading, the aisle width and the lifting method for the OPzS2-420 all depend on it. A tender that leaves the weight open invites a range of answers.

§3 — The Choice

The OPzS2-420 2V420Ah is the right cell when the battery room is attended, the service contract exists, and the owner values a lower purchase price over a lower lifetime cost. The string arithmetic from published figures is:

String configuration	Cells	Bus voltage	Nominal energy (arithmetic)	Charger class at the 84 A limit (arithmetic)	Service visits per year at a 3-6 month refill interval
48 V system	24	48 V	24 x 2 V x 420 Ah = 20.16 kWh	24 x 84 A = 2,016 A at 48 V = 96.8 kW	2 to 4
108 V (110 V) system	54	108 V	54 x 2 V x 420 Ah = 45.36 kWh	54 x 84 A = 4,536 A at 108 V = 490 kW	2 to 4
216 V (220 V) system	108	216 V	108 x 2 V x 420 Ah = 90.72 kWh	108 x 84 A = 9,072 A at 216 V = 1.96 MW	2 to 4
380 V three-phase DC	190	380 V	190 x 2 V x 420 Ah = 159.6 kWh	190 x 84 A = 15,960 A at 380 V = 6.07 MW	2 to 4

The refill column is the line that decides the total cost. Two to four site visits a year, each one a technician, a vehicle and a record, multiplied across every battery room in the estate, is the difference between the flooded and the sealed product over ten years.

The comparison that a procurement team actually needs is between the OPzS2-420 2V420Ah and its sealed gel equivalent, and both sides of it are published:

Parameter	OPzS2-420 (flooded tubular)	OPzV2-420 (sealed gel tubular)
Capacity	420 Ah at C10	420 Ah at C10
Dimensions	145 x 206 x 471 mm	145 x 206 x 471 mm
Total height over terminals	525 mm	506 mm
Weight	24.0 kg without electrolyte, 32.0 kg with electrolyte	31.5 kg
Cycle life (published)	1,500-2,500 cycles at 80% DOD	1,500+ at 80% DOD; 2,500 at 50% DOD; 4,000 at 30% DOD; 5,500 at 20% DOD; 800 at 100% DOD
Float voltage	2.23 V/cell	2.23 V/cell
Maximum charge current	84 A	84 A
Internal resistance	0.56 mOhm	0.62 mOhm
Self-discharge	3% per month	2% per month
Discharge temperature range	-25 to +65 °C	-40 to +65 °C
Charge temperature range	-20 to +65 °C	-30 to +65 °C
Installation	Vertical only	Vertical, horizontal or on its side; never inverted
Maintenance	Water refill every 3-6 months	Maintenance-free; no water or acid refill
Float design life	20+ years at 20 °C	20+ years at 20 °C

The OPzS2-420 2V420Ah is better than a sealed cell for a manned room because it is cheaper per kWh, because the transparent container lets a technician read the state of the plates and the electrolyte level without instruments, and because the published cycle band of 1,500-2,500 at 80% DOD is competitive for a duty that cycles. It is better than a conventional flat-plate flooded cell because the die-cast tubular positive plate resists grid corrosion under repeated deep discharge, and the 0.56 mΩ internal resistance keeps the voltage drop low during a high-current discharge.

It is worse than the gel alternative in three specific, measurable ways: the gel cell removes the service visit entirely, it may be installed horizontally, and it carries a wider charge temperature window in a hot climate. For an unattended site, the choice is not close. For a manned room with a service contract and a technician on payroll, the flooded cell remains a defensible procurement.

Against a lithium installation, the comparison is dominated by cycle life rather than price. Published lead-acid AGM cycle figures sit in the 400-800 band at 80% DOD and comparable LFP traction and stationary chemistries publish 3,000-5,000 cycles at 80% DOD. A site that cycles the bank daily should model the lithium option over the full replacement horizon; a site that floats with occasional backup discharge rarely needs to.

For the wider range context around the OPzS2-420, the tubular flooded OPzS overview shows the capacity ladder the OPzS2-420 sits on, and the CHISEN company page sets out the manufacturing base and the certification scope behind the cell.

§4 — The Framework

Seven criteria decide whether the OPzS2-420 2V420Ah is the right cell for a specific site. Take them in order, because the first one decides most of the others.

Establish who maintains the battery room. A manned room with a service contract and a technician means a flooded cell is viable. An unattended site, an island station, a border post or a rail trackside hut means it is not, and the sealed gel alternative takes over.
Fix the string voltage and count the cells. 24, 54, 108 or 190. The string voltage sets the charger, the DC bus, the protection and the string fuses.
Write the rating basis into the order. 420 Ah at C10 to 1.80 V per cell, and request the discharge curve with the certificate.
Design for the vertical-only rule. 525 mm over the terminals, upright, with the electrolyte level accessible from the front of the rack for a visual check. Build the aisle and the service access around that, because a technician with a water bottle and a torch has to reach every cell.
Price the service visits. Two to four per year per battery room, with vehicle, technician and record time, over the 20-year published float life.
Check the temperature range against the room. Discharge -25 to +65 °C and charge -20 to +65 °C. The flooded cell’s charge ceiling is 5 °C below the sealed gel alternative, which matters in an unconditioned room in the Gulf or northern India during an equalise cycle.
Request the missing weight. The factory page does not publish it. Get the datasheet figure before you release the rack and floor-loading design.

§5 — The Trust

The OPzS2-420 2V420Ah is a mature product with a long field history, and the traps around it are administrative rather than technical. Name them before you sign.

Ask for the capacity certificate at C10 with the cutoff. A 20-hour figure for a cell of this size will read better on paper than the C10 figure, and that is precisely why the basis belongs in the purchase order.

Ask for the cycle test profile. “1,500-2,500 cycles at 80% DOD” needs a cutoff voltage, a temperature and a charge regime behind it. A supplier who cannot produce that profile has not run the test.

Demand the weight. It is not published. A supplier who cannot produce the filled weight of the OPzS2-420 from a datasheet is sourcing rather than manufacturing, and the rack design depends on it.

Confirm the electrolyte specification. Dilute sulphuric acid at 1.24 +/- 0.01 g/cm³ fully charged, with a vent plug and a transparent SAN container. Ask for the electrolyte volume of the OPzS2-420, the maximum refill interval the supplier will warrant, and the distilled water specification they expect the site to use.

Check the standards list, and check what it means for your market. IEC 60896-11, DIN 40736-1, GB/T 19638.2, Eurobat Long Life and BS 6290 Part 4 / UL 1989 are published for this cell, and they map to specific acceptance regimes rather than being decorative.

Agree the warranty at the real operating point. Float life is published as 20+ years at 20 °C. Ask what the warranty becomes in a 35 °C room, with a refill interval of three months rather than six, and with occasional deep discharge to 80% — those are the conditions that actually determine whether the claim is honoured in year eight.

Fix the service contract, not just the battery. A flooded cell installed without a defined maintenance contract is a deferred liability with a 20-year fuse. Put the visit frequency, the readings to be taken, the water specification and the escalation path into the same agreement.

§6 — FAQ

Q1. What is the rated capacity of the OPzS2-420 2V420Ah? 420 Ah at the 10-hour rate with a 1.80 V per cell cutoff. The 20-hour rate is not published for this model, so any quotation stating 420 Ah at 20 hours is quoting a different rating basis and the two should not be compared without the discharge curve.

Q2. What does the OPzS2-420 weigh? The datasheet publishes the weight as 24.0 kg without electrolyte and 32.0 kg with electrolyte, so a 54-cell string is 1,728 kg of cells with electrolyte. The sealed gel equivalent in the same capacity class publishes 31.5 kg, which is a useful cross-check.

Q3. Can the OPzS2-420 be installed on its side? No. The OPzS2-420 2V420Ah is a flooded cell and must be installed vertically, because the liquid electrolyte leaks if the cell is tilted or laid horizontal. The sealed gel alternative in the same capacity class may be installed vertical, horizontal or on its side, and that difference often decides a retrofit.

Q4. How often does it need water, and what does that cost? A water refill every 3-6 months, which is two to four service visits a year per battery room. On a 24 or 54 cell string that means the technician, the vehicle, the distilled water and the record, every time. Over the published 20-25 year float life at 20 °C, that routine is a permanent operating cost and it is the main reason to choose a sealed cell where nobody visits the room.

Q5. What is the difference between the float and the equalise voltage? Float is 2.23 V per cell at 25 °C with -3 mV per °C compensation, and the cycle or equalise voltage is 2.35 V per cell at 25 °C (2.40 V for solar and wind regulation). The charger has to be programmed to both, and the temperature compensation has to be active, because a battery room in Cairo, Durban or Karachi rarely sits at 25 °C.

Q6. What are the temperature limits? Discharge -25 to +65 °C, charge -20 to +65 °C, storage -25 to +45 °C. The charge ceiling of 55 °C is 5 °C below the sealed gel alternative in the same class, which is worth checking against the peak internal temperature of the cell in an unconditioned room.

Q7. How long does the battery last, and what does that depend on? The published float design life is 20+ years, in practice 20+ years at 20 °C, and the published cycle band is 1,500-2,500 cycles at 80% DOD at 25 °C. Both are conditional on temperature and on the maintenance routine: a room held at 25 °C with a disciplined refill interval will reach the top of that range, and a hot room with a neglected refill will not.

Q8. Can it be stored, and for how long? The published data allows 9-12 months of storage without recharging at 20-25 °C, with self-discharge of 3% per month. A project with OPzS2-420 cells that is delayed at customs, at the port of Mombasa, Lagos, Santos, Jebel Ali or Port Said should plan a check and a top-up charge before the string goes into service.

Q9. What should be in the purchase order? The model, the capacity and its basis (420 Ah at C10 to 1.80 V/cell), float and equalise voltages with the temperature compensation, the 84 A maximum charging current, the cycle band with its depth of discharge, the operating temperature range, the vertical-only installation requirement, the refill interval and water specification, the electrolyte volume and specific gravity, the standards, the filled weight from the datasheet, and the warranty terms with a named local claim contact.

Expert Summary

The OPzS2-420 2V420Ah is a 2 V, 420 Ah flooded tubular-plate lead-acid cell for manned stationary installations: telecom base stations with attended rooms, railway signalling, emergency lighting, industrial control power, marine systems, medical equipment, large UPS above 500 kVA and renewable storage. The decisive published specification is that 420 Ah is a 10-hour rate to a 1.80 V per cell cutoff, and the product is built around die-cast low-antimony tubular positive plates with liquid dilute sulphuric acid electrolyte at 1.24 g/cm³ in a transparent SAN container with a vent plug. The cell measures 145 x 206 x 471 mm, 525 mm over the terminals, carries a Phi20-M8 terminal with a 10-12 N.m torque, publishes 1,500-2,500 cycles at 80% DOD at 25 °C, floats at 2.23 V per cell with -3 mV per °C compensation, equalises at 2.35 V per cell (2.40 V for solar and wind regulation), accepts a maximum charge current of 84 A, has 0.56 mΩ internal resistance and 3,500 A short-circuit current, self-discharges at 3% per month with 9-12 months of storage, operates -25 to +65 °C on discharge and -20 to +65 °C on charge, and carries a 20-25 year float design life at 20 °C. It must be installed vertically because the electrolyte leaks, it needs a water refill every 3-6 months, and the filled weight is not published on the factory page and must be requested from the datasheet. String arithmetic from published figures: 24 cells give 48 V at 20.16 kWh and a 96.8 kW charger class, 54 cells give 108 V at 45.36 kWh, 108 cells give 216 V at 90.72 kWh, and 190 cells give 380 V at 159.6 kWh. Against the sealed gel equivalent in the same class, the flooded cell is cheaper and lets a technician read the electrolyte level directly, while the gel cell removes every service visit, may be installed horizontally, self-discharges at 2% instead of 3% per month and carries a 5 °C higher charge ceiling. The non-negotiables are the C10 basis in writing, the vertical-only installation, a priced and contracted refill schedule, the missing weight requested before the rack design is released, and a warranty written at the real operating temperature rather than at 25 °C.

Contact CHISEN — 24-Hour Response

CHISEN replies to technical and commercial enquiries within 24 hours and returns a written sizing recommendation with published data, not a catalogue listing.

Send us the information below and we will return the string configuration, charger class, float and equalise settings and the service plan for the OPzS2-420 2V420Ah in your project:

Site type, and whether the battery room is attended on a fixed schedule
Panel voltage and the duty profile, including expected depth of discharge and cycle frequency
Ambient temperature range and whether the room is conditioned or ventilated
Available charger class and the maintenance contract you can support
Annual volume, delivery terms and destination port

Email: sales@chisen.cn WhatsApp: +86 131 6622 6999 Call: +86 131 6622 6999

Technical enquiries, project drawings and tender documents: leadacidbattery.cn

Related CHISEN Buyer Guides

October 23, 2026

opzs2 770 2v770ah tubular flooded battery dc plant telecom 2026 10 22

OPzS2-770 2V770Ah Tubular Battery: DC Plant Sizing Guide

Reading time: 20 minutes | For: telecom power engineers, DC panel and data-centre engineers, solar EPC contractors, railway signalling engineers, industrial power distributors and OEM buyers across Africa, the Middle East, South Asia, South-East Asia and Latin America

Answer First

The OPzS2-770 2V770Ah is a 2-volt, 770 amp-hour stationary battery cell built on a tubular positive plate with liquid dilute-sulphuric-acid electrolyte in a vented, transparent-container case, constructed to DIN 40736-1 and IEC 60896-11. It is the flooded workhorse of the stationary lead-acid world — the cell you specify when the site has a staffed room, a maintenance route, and a duty cycle that rewards deep cycling over pure float standby.

Five numbers decide the procurement:

770Ah at the 10-hour rate (C10) to 1.80 V per cell — one cell, six bus voltages: 24 cells = 48V, 54 cells = 108V (110V DC panel), 108 cells = 216V (220V industrial), 190 cells = 380V three-phase DC.
254 × 210 × 471 mm, 525 mm total height — a transparent SAN container, so you can see the electrolyte level and plate condition from the aisle. No infrared camera, no guesswork.
1,500–2,500 cycles at 80% depth of discharge — roughly 1.5–2× the cycle life of a flat-plate AGM at the same amp-hour rating, because the tubular plate holds active material mechanically instead of relying on a corroding grid.
3,900 A short-circuit current and 0.55 mΩ internal resistance fully charged at 25°C, giving better voltage retention under the high-rate pulses a DC panel or a railway signalling supply actually produces.
20–25 years of float design life at 25°C — and that figure halves for every 10°C rise in ambient, which makes room design a battery-life decision rather than a facilities decision.

The honest caveat: the OPzS is not maintenance-free. It needs a water top-up every 3–6 months and must be installed upright. If your site is unmanned, remote, or in a sealed container where nobody will ever walk past the rack, the sealed tubular gel OPzV is usually the lower total-cost answer despite the higher purchase price. That trade-off is the whole decision, and §3 quantifies it over ten years.

Key Takeaways

OPzS2-770 = 2V cell, 770Ah at C10, 254 × 210 × 471 mm (525 mm total height), Φ20-M8 terminal, flooded tubular plate, SG 1.24 electrolyte. Published figures.
One cell, six bus voltages. 24 cells = 48V, 30 = 60V, 54 = 108V, 108 = 216V, 190 = 380V. Write the cell count into the purchase order, not just the bus voltage.
Tubular plate beats flat plate on cycle life, and loses on footprint. 1,500–2,500 cycles at 80% DOD versus roughly 500–1,000 for flat-plate AGM — but a 770Ah tubular cell occupies more floor area per kWh than an AGM block of the same capacity.
Capacity derates hard above 35°C. Float life halves for every 10°C rise (Arrhenius): 25°C ≈ 20–25 years, 35°C ≈ 10–12 years, 45°C ≈ 5–6 years.
Sizing is almost always done on the wrong discharge rate. The same cell rated 770Ah at C10 delivers roughly 660Ah at C3. Specify the rate your application actually runs at.
CHISEN supplies factory-direct with 8 production bases, 70 GWh annual capacity, CE / ISO 9001 / ISO 14001 / UL / IEC certification, and export documentation prepared for 60+ destination markets including SONCAP, PVOC, SASO, BIS and ESMA on request.

§1 — The Published Specification Table

Parameter	Specification
Model	OPzS2-770
Nominal voltage	2 V (single cell)
Rated capacity	770 Ah at C10 (10-hour rate to 1.80 V/cell at 20–25°C)
Dimensions (L × W × H)	254 × 210 × 471 mm
Total height with terminals	525 mm
Terminal type	Φ20-M8 bolt terminal (Φ16-M6 and Φ24-M10 available)
Electrolyte	High-purity low-density dilute sulphuric acid, SG 1.24 ± 0.01 g/cm³ fully charged
Maximum charging current	160 A
Maximum discharge current	2,200 A over 5 seconds
Internal resistance	0.55 mΩ (fully charged, 25°C)
Short-circuit current	3,900 A
Cycle life	1,500–2,500 cycles at 80% DOD; 2,500–4,000 at 50% DOD; 4,500–6,500 at 30% DOD
Float / design life	20+ years (20+ years at 20 °C float)
Float voltage	2.23 V/cell at 25°C, compensation −3 mV/°C/cell
Equalise voltage	2.35 V/cell at 25 °C, compensation −5 mV/°C/cell
Construction	Tubular positive plate, vented transparent container, floodable
Case material	Transparent SAN, flame-retardant
Certifications	IEC 60896-11:2002, DIN 40736-1:1985, GB/T 19638.2-2014, YD/T 1360, Eurobat Long Life, BS 6290 Part 4, UL 1989
Transport	IMDG Class 8, UN2794, MSDS supplied
Environmental	EU RoHS, REACH, WEEE
Destination approvals	SONCAP, PVOC, SASO, BIS, ESMA arranged on request
Applications	PV and solar storage, wind and off-grid storage, medium UPS, industrial backup, data-centre UPS, telecom base stations, railway signalling, marine and medical equipment, emergency lighting, diesel engine starting

Two data-integrity flags you should know about before you order. We would rather tell you this than have you discover it at the loading dock. On the currently published model page for the OPzS2-770, two fields are inconsistent with a 770Ah cell:

The discharge-rate table is copied from a much smaller cell. It lists 1 HR at 50 Ah, 3 HR at 75 Ah, 10 HR at 100 Ah and 240 HR at 130 Ah — values in the range of a 100Ah cell, not a 770Ah cell. For a genuine 770Ah cell those figures should be roughly 7.7 times higher.
The weight field is not consistently published. A figure in the region of 12.6 kg appears in the page content, which belongs to a far smaller case; a 770Ah tubular cell of this size is several times that.

We are not going to reproduce either number as if it were correct. Instead: request the current datasheet with your quotation and confirm the weight, the discharge table and the terminal option against it before you release the order. Template-copy errors of this kind are common across model pages in this industry, and the ten-minute check protects a bank that costs several thousand dollars. The verified figures in the table above — capacity, dimensions, terminal type, internal resistance, short-circuit current, cycle life, float life and standards — are the ones we stand behind.

What “OPzS2-770” tells you. OPz identifies the tubular-plate stationary range. S denotes flooded, vented construction, as opposed to V for valve-regulated gel. The 2 is the cell voltage. 770 is the amp-hour rating at the ten-hour rate. In the DIN 40736-1 convention, the number following the letter pair is always the ten-hour rate, which is why the rating is directly comparable across the whole OPz range.

String configuration reference.

Bus voltage	Cells in series	String capacity	Nominal energy	Typical application
24 V	12	770 Ah	18.48 kWh	Small telecom sites, DC control panels
48 V	24	770 Ah	36.96 kWh	Telecom DC plant, small data centre, solar hybrid
60 V	30	770 Ah	46.20 kWh	Solar installations matching a 60V inverter input
108 V	54	770 Ah	83.16 kWh	110V DC panel, railway signalling
216 V	108	770 Ah	166.32 kWh	220V industrial distribution, large UPS
380 V	190	770 Ah	292.60 kWh	Three-phase DC, large utility substations

Individual model pages confirm the variant: OPzS2-770 2V770Ah specifications →. For the full flooded tubular range, see the OPzS tubular flooded battery series →.

§2 — The Pain: Where Stationary Projects Actually Lose Their Budget

The room nobody walks into. The single largest cost surprise in stationary lead-acid is the battery room itself. A flooded installation needs ventilation for hydrogen, a floor with drainage and acid resistance, a maintenance route, lighting, and — critically — someone who actually visits. When a project is built and then handed to an operator with no routine maintenance, a flooded bank specified for a 20-year design life delivers five.

Temperature is the number nobody put in the specification. Float life follows the Arrhenius rule: every 10°C rise roughly halves float life. A 20-year-plus cell installed in a 45 °C unventilated container room delivers roughly five years. No chemistry fixes this; only thermal design does. And in Nairobi, Lagos, Karachi, Chennai, Dubai, Manila and Jakarta, indoor ambient frequently sits above 35°C for most of the year.

Ambient temperature	Capacity at 10 hr	Practical float life
40°C	108%	~5 years
35°C	—	~10–12 years
25°C	100% (rated)	20+ years
0°C	85%	—
−15°C	65%	—

Note the second row carefully: above 25°C a lead-acid cell delivers more than its rated capacity at a low discharge rate, which is a genuine bonus for a telecom site — but it buys no extra calendar life, because heat accelerates the ageing chemistry faster than it increases capacity.

Sizing on the wrong discharge rate. 770Ah is the ten-hour rate rating. At the three-hour rate the same cell delivers roughly 660Ah, and at the one-hour rate roughly 570Ah. A DC panel sized for a deep discharge event but quoted at C10 will be under-specified by 15–20% on the worst event of its life — which is precisely the event the system exists to survive.

The 48V string is not a 48V string. Every cell in a series string carries the full bus voltage, and the string’s usable capacity is limited by its weakest cell. A 24-cell string with one cell at 1.95V open circuit imposes 46.8V across the bus, not 48V. Cell-to-cell imbalance — not a dead cell — is what actually ends strings early.

§3 — The Choice: Flooded Tubular vs Sealed Gel vs Lithium, Quantified

The table below models a realistic duty: one 48V telecom DC plant or small data-centre site, 24 × OPzS2-770 cells, float standby with periodic discharge events, 30°C average ambient, ten-year horizon. All figures are a stated-assumption model so you can rebuild it with your own tariff, labour rate and duty profile — not a quotation.

Cost line (10 years, per 48V / 770Ah string)	Flooded tubular OPzS	Sealed tubular gel OPzV	LFP 48V string
Initial purchase	$2,880	$3,360	$6,400
Electricity over 10 years	$1,450	$1,280	$980
Watering and inspection labour	$2,400	$320	$90
Ventilation and cooling provision	$640	$480	$220
Replacement inside the 10-year window	$2,880	$3,360	$0
Installation labour	$900	$700	$400
10-year total cost of ownership	$11,150	$9,500	$8,090

Read the third row down. The labour line is the whole argument. Flooded tubular loses $2,080 over ten years to watering and inspection visits, and a further $2,880 to one mid-life replacement. Those two lines together are the entire gap to the sealed gel option, which costs more per cell and less in total.

Where the conclusion changes:

Flooded OPzS wins where the site has a staffed maintenance route, a water supply and a proper ventilated battery room — because it is the lowest-cost product by a wide margin and its cycle life is the highest in the comparison. If a technician already visits the site monthly, flooded is the right answer.
Sealed tubular gel OPzV wins at unmanned, remote and containerised sites: same tubular plate cycle-life advantage, no watering route, and installation in any orientation except inverted. It is the most common correct answer for telecom base stations and remote solar sites.
Lithium wins over a ten-year horizon in this model, but with two conditions attached: the capital must be available, and the cells must carry the listing your destination requires. Some telecom and utility operators are bound by UL 1973, UL 9540A or equivalent national approvals where lead-acid passes more easily. Confirm before committing.
Lithium’s advantage disappears if your horizon is short. At five years the numbers are much closer, and if the site has a maintenance route, flooded or gel lead-acid usually wins.

The same model, if the site is manned and warm. Flooded’s disadvantage is labour that already exists. Where a technician’s monthly visit is already on the schedule for other reasons, the labour line shrinks toward $400 and the ten-year totals converge to roughly $9,150 flooded, $9,500 gel and $8,090 lithium. At that point the decision is about cycle life, footprint and process discipline rather than cost.

§4 — The Framework: Seven Criteria Before You Issue a Purchase Order

1. Establish the discharge profile, then the rate you will size at. DC plant duty is float with occasional deep discharge. Size for the worst event at the rate the event actually occurs, then apply the end-voltage table in §5. Do not size on the C10 nameplate for a deep event.

2. Fix the cell count explicitly. 24 cells = 48V, 30 = 60V, 54 = 108V, 108 = 216V, 190 = 380V. Write “24 × OPzS2-770, 48V” on the order. A 48V string built from 24 two-volt cells and a 48V string built from a different cell count are not the same battery, and mixing them across a site is how string imbalance starts.

3. Design the room before the cells arrive. Ventilation for hydrogen, drainage and an acid-resistant floor, lighting, a maintenance route, and a working clearance of at least 50 mm behind each string. Check the rack against the cell drawing — 254 × 210 mm on a 525 mm tall cell with a Φ20-M8 terminal leaves very little room for the busbar and the interconnects.

4. Set float voltage and compensation at the controller. 2.23 V per cell at 25°C with −3 mV/°C/cell per °C per cell compensation applied by the charger, not by the battery. Hold float inside ±1% (±25 mV). Float current should stay below 5 mA per Ah — roughly 3.9 A for a 770Ah cell.

5. Confirm the charger current against the cell’s 160 A limit. Maximum charging current is 160 A, about 0.21C. A charger sized on the nominal bus voltage alone will routinely deliver more than that during a cold-morning recovery, and chronic overcharge is the most common cause of early float failure.

6. Demand the documentation and the destination approvals. IEC 60896-11:2002 and DIN 40736-1:1985 test reports, UL 1989, BS 6290 Part 4, Eurobat Long Life, GB/T 19638.2-2014 and YD/T 1360, plus the MSDS, UN2794 transport appraisal and certificate of origin. Where the destination requires SONCAP, PVOC, SASO, BIS or ESMA, establish who arranges it and the lead time before you commit.

7. Build the commissioning protocol into the scope. Initial electrolyte top-up, first full charge, a capacity test if the cells were stored, cell-to-cell voltage balance within ±0.05 V, and a photographed baseline per cell. Without that baseline, month-24 diagnosis is guesswork.

§5 — The Trust Layer: The Numbers You Should Memorise

Manufacturing controls you can verify before you energise the bank. CHISEN has manufactured stationary lead-acid since 2002, with 8 production bases and 70 GWh annual capacity. The OPzS line runs statistical process control on the four process steps that actually determine life: paste coating, plate-group assembly, formation and sealing. Every cell receives 100% outgoing inspection covering capacity, internal resistance, open-circuit voltage and visual condition. Third-party pre-shipment inspection by SGS, TUV, BV or CTI is available on request. Company details: about CHISEN Battery →.

End voltage by discharge rate (per IEC 60896 and GB/T 19638) — this is the table that decides whether a 770Ah cell is correctly specified.

Discharge current	End voltage per cell	Typical application
I < 0.05 C10	≥ 1.90 V	Monitoring and very low current backup
0.05 C10 ≤ I < 0.08 C10	≥ 1.85 V	Low current float backup
0.08 C10 ≤ I < 0.2 C10	≥ 1.80 V	Standard 10-hour discharge — the rated condition
0.2 C10 ≤ I < 0.6 C10	≥ 1.75 V	5-hour discharge
0.6 C10 ≤ I < 1.0 C10	≥ 1.70 V	1-hour discharge
1.0 C10 ≤ I < 2.0 C10	≥ 1.60 V	High-power pulse

Float voltage compensation reference.

Ambient	Compensated float voltage
15°C	2.26 V
25°C	2.23 V (no correction)
35°C	2.20 V
45°C	2.17 V
55°C	2.14 V

Equalise at 2.35–2.40 V per cell monthly, with a −5 mV/°C compensation, and cap the duration at 24 hours.

The seven failure modes that shorten OPzS life, and what prevents each.

Failure mode	Root cause	Prevention
Capacity fade from dry-out	Water lost through the vent plug in a hot room	3–6 month watering route; check SG monthly, top to 1.240 ± 0.01
Plate sulphation	Prolonged float below 2.20 V per cell, or chronic undercharge	Verify charger float output and temperature compensation quarterly
Stratum separation	Extended periods at low temperature after partial discharge	Monthly equalise cycle; store above 5°C when not in service
Terminal corrosion and heating	Torque below specification, or loose interconnects	10–12 N·m on every Φ20-M8 terminal, re-torque annually
Thermal runaway in the string	Poor cell-to-cell balance, high ambient, no ventilation	Maintain ≥50 mm clearance; monitor cell spread < ±0.05 V
Premature capacity loss	Repeated deep discharge below the end voltage	Respect the end-voltage table in this section
Under-sized bank	Sizing performed at C10 when the duty is C3	Size at the application’s real discharge rate with 20–30% margin

Commissioning checklist — do these before the first load test.

Check the electrolyte level and specific gravity on every cell; top with deionised or distilled water to the marked line. SG should read 1.240 ± 0.01 g/cm³ at 25°C.
Terminal torque check at 10–12 N·m. Photograph the torque wrench reading per string — that photograph is the document that surfaces in warranty disputes.
Cell-to-cell voltage spread within ±0.05 V before the string is commissioned. Anything wider requires an equalisation cycle before energising.
Confirm the charger float setpoint at 2.23 V per cell and temperature compensation at −3 mV/°C/cell at the controller, not just at the battery.
Log the baseline: per-cell voltage, specific gravity, ambient temperature and room position. Without that baseline you cannot diagnose anything at month 24.

Altitude derating (per GB/T 19638). Up to 3,000 m normal operation; above 3,000 m, derate approximately 8% of capacity for every additional 1,000 m; above 5,000 m requires a special low-pressure, reinforced-case variant. Railway, mining and high-altitude installations should carry that in the calculation, not discover it on site.

Safety. A 770Ah flooded cell produces approximately 3,900 A on direct short. Never place a metal tool across terminals. Charging generates hydrogen — no flames, no sparks, no smoking in the battery room. Wear eye protection and acid-resistant gloves; dilute sulphuric acid requires immediate 15-minute flush with clean water if it reaches the eye. Handle and dispose of cells under the UN2794 dangerous-goods procedure and never drain electrolyte into a floor drain.

§6 — FAQ: 9 Questions Stationary Procurement Teams Ask

Q1. What is the difference between OPzS2-770 and OPzV2-770? OPzS2-770 is flooded: liquid sulphuric acid in a transparent vented case, requiring a 3–6 month watering interval and upright installation only. OPzV2-770 is valve-regulated gel: sealed, maintenance-free, installable in any orientation except inverted. Both use tubular positive plates. Choose OPzS for staffed rooms and daily deep cycling; choose OPzV for unmanned or space-constrained sites.

Q2. How much usable capacity does a 770Ah cell actually deliver? 770Ah is the ten-hour rate rating to 1.80 V per cell. At the five-hour rate the same cell delivers roughly 700Ah, at the three-hour rate roughly 660Ah, and at one hour roughly 570Ah. Size your bank at the discharge rate your application actually runs at, not at the nameplate.

Q3. How many cells do I need for a 48V system? 24 cells in series for 48V, 30 for 60V, 54 for 108V (110V DC panel), 108 for 216V (220V industrial), and 190 for 380V three-phase DC. Always confirm the cell count against your actual DC panel nominal before ordering.

Q4. What float voltage should I set? 2.23 V per cell at 25°C, with temperature compensation of −3 mV/°C/cell per cell applied by the charger. Equalise monthly at 2.35–2.40 V per cell for no more than 24 hours, with an independent −5 mV/°C per cell compensation. Hold float inside ±1%.

Q5. How often does an OPzS2-770 need water? Every 3–6 months in a temperate room, more often in hot or dry climates. Check specific gravity monthly and top with deionised or distilled water to the marked line at 1.240 ± 0.01 g/cm³ at 25°C. Never top with tap water and never add acid.

Q6. What is the cycle life, and does it matter for my application? 1,500–2,500 cycles at 80% depth of discharge, 2,500–4,000 at 50% DOD, and 4,500–6,500 at 30% DOD. For pure float telecom duty the cycle figure is largely irrelevant and the 20–25 year float life at 25°C is what matters. It becomes the deciding number wherever the bank is cycled regularly — solar with evening peaks, rail signalling with track battery duties, or diesel engine starting packages.

Q7. Can I install it on its side? No. The flooded cell must be installed upright to prevent electrolyte leakage out of the vent plug. If your cabinet cannot accommodate upright cells, specify the sealed OPzV variant instead.

Q8. What documents ship with the battery? The standard export pack includes the commercial invoice, packing list, certificate of origin, MSDS, UN2794 transport appraisal and full IEC 60896 test reports. Product certification covers IEC 60896-11, DIN 40736-1, GB/T 19638.2, YD/T 1360, Eurobat Long Life, BS 6290 Part 4 and UL 1989. Destination approvals such as SONCAP, PVOC, SASO, BIS and ESMA are arranged on request.

Q9. What do I need to send for a quotation? Send the bus voltage and the cell count, the backup load and duration, the worst-case ambient temperature, the site situation (staffed room, container, or unattended), the altitude, and the destination country for documentation. We return a complete Excel sizing table with the quotation within 24 hours, and sample cells ship on request.

Expert Summary

For stationary procurement teams evaluating the OPzS2-770 2V770Ah, the decisive facts are these. It is a 2-volt stationary cell rated at 770 amp-hours at the ten-hour rate to 1.80 V per cell, built on a tubular positive plate with flooded dilute sulphuric-acid electrolyte at specific gravity 1.24 in a transparent vented SAN container, compliant with DIN 40736-1:1985 and IEC 60896-11:2002, with published dimensions of 254 × 210 × 471 mm and a total height of 525 mm, a Φ20-M8 terminal, a maximum charging current of 160 A, a maximum discharge current of 2,200 A over five seconds, an internal resistance of 0.55 mΩ fully charged at 25°C and a short-circuit current of 3,900 A. Tubular plate construction delivers 1,500–2,500 cycles at 80% depth of discharge, 2,500–4,000 at 50% and 4,500–6,500 at 30%, together with a 20+ year float design life at 20 °C that halves for every 10°C rise in ambient temperature. Float is 2.23 V per cell with −3 mV/°C/cell compensation and equalise 2.35–2.40 V per cell with −5 mV/°C. A single cell builds 24V, 48V, 60V, 108V, 216V and 380V strings at 12, 24, 30, 54, 108 and 190 cells respectively, with the same 770Ah string capacity in each case. Sizing errors overwhelmingly trace to using the C10 nameplate for a deeper duty, where real deliverable capacity falls to roughly 86% of specification at C3. In a modelled 48V telecom DC plant at 30°C ambient over a ten-year horizon, total cost of ownership per string is approximately $11,150 for flooded tubular, $9,500 for sealed tubular gel and $8,090 for LFP, with the flooded-versus-gel difference driven almost entirely by watering labour and one mid-life replacement rather than by purchase price. Two fields on the currently published model page — the discharge-rate table and the weight — are inconsistent with a 770Ah cell and should be confirmed against the current datasheet before an order is released. CHISEN supplies these cells factory-direct from 8 production bases with 70 GWh annual capacity, full CE / ISO 9001 / ISO 14001 / UL / IEC certification, export documentation prepared for more than 60 destination markets, third-party pre-shipment inspection on request, and free engineering sizing returned within 24 hours.

Contact CHISEN — 24-Hour Response

CHISEN Battery — 20+ years manufacturing stationary lead-acid, exporting to 60+ countries.

Email: sales@chisen.cn — full quotation and sizing table within 24 hours
Phone / WhatsApp: +86 131 6622 6999
WhatsApp: https://wa.me/8613166226999
Model page: https://www.chisen.cn/en/OPzS2-770/2V770Ah.html

Send us bus voltage and cell count + backup load and duration + worst-case ambient temperature + site situation + altitude + destination country, and our engineering team returns a complete sizing sheet — cell count, standard capacity selection, rack dimensions, temperature derating applied, charger profile and documentation scope — within one working day. Sample cells are available on request for your own capacity test before you commit to a full bank.

Related reading: for the sealed tubular alternative at the same capacity, see the OPzV series tubular gel battery specifications →. For cycle-life and TCO comparison across tubular and flat-plate technologies, see the tubular plate battery technical overview →. For the electric vehicle range that covers traction duties, see the EVF electric road vehicle series →. Full CHISEN product range across 2V, 6V, 8V and 12V voltages: lead-acid and lithium battery product catalogue →.

Published by CHISEN Battery. Standard data per CHISEN OPzS2-770 published datasheet, IEC 60896-11:2002 and DIN 40736-1:1985. TCO figures are a stated-assumption model for comparison, not a quotation. Two published fields on the source model page (discharge-rate table and weight) are pending verification and are not reproduced here as fact — request the current datasheet. Availability, certification and destination-specific approvals confirmed on request.

Related CHISEN Buyer Guides

October 23, 2026

6 evf 120 12v120ah agm battery forklift agv traction 2026 10 22

6-EVF-120 12V120Ah AGM Battery: Specs, Packing and 5-Year TCO

Reading time: 19 minutes | For: procurement managers, fleet engineers, industrial equipment OEMs, e-mobility distributors and freight operators across Africa, the Middle East, South America and South-East Asia

Answer First

The 6-EVF-120 12V120Ah is a 12-volt, 120 amp-hour sealed AGM (VRLA) deep-cycle battery built for electric road and industrial vehicles — 2-ton electric forklifts, stackers, automated guided vehicles, 4–8 seat sightseeing vehicles, golf carts, floor scrubbers and electric boats. It is a 6-cell battery (6 × 2V), so one unit gives you a full 12V system, and four units in series give a 48V traction pack.

Five numbers decide the procurement:

120Ah at the 3-hour rate (C3) — and this is the single most misunderstood figure in the whole category. The same cell delivers only about 95–100Ah at C10. A quotation that says “120Ah” without naming the rate is hiding a 20–25% gap in usable energy.
407 × 170 × 240 mm at 40.0 kg — 160 kg of battery in a 48V four-unit pack. That weight sits directly on the chassis load rating and the frame design, which is why the 6-EVF-120B variant (338 × 172 × 280 mm) exists for space-constrained trucks.
24.0 A maximum charge current — a 30 A charger is over-sized for this cell and will push it into excess voltage and heat. Match the charger, do not oversize it.
350–600 cycles at 50–80% depth of discharge, with a 2–5 year design life and operating range −15°C to 50°C.
Total sealed, maintenance-free construction — no watering interval, no acid mist, installable in any orientation except inverted, and the lowest 5-year total cost of ownership of the three technologies compared below.

The honest caveat: AGM is not automatically the right answer. For a fleet running two shifts a day in a 40°C unventilated yard with an in-house technician, flooded lead-acid still delivers the lowest cost per cycle. For an unmanned AGV fleet, a lithium pack beats both on weight and maintenance. The choice is a duty-cycle decision, and we quantify it in §3 with real numbers rather than slogans.

Key Takeaways

6-EVF-120 = 12V, 120Ah at C3, 6 cells, φ20-M8 terminal, 407 × 170 × 240 mm, 40.0 kg, 24.0 A max charge current. Published figure, not a range.
C3 is the rating that matters. A 120Ah C3 cell gives roughly 95–100Ah at C10. Size your bank on the discharge rate your application actually runs at, then add 25–30% margin.
Pack math is simple: 4 units = 48V, 6 units = 72V, 8 units = 96V — each with a 120Ah string capacity, because series wiring adds voltage and not amp-hours. A 6-unit 72V pack of 6-EVF-120 weighs 240 kg — check the chassis before you commit.
AGM wins on 5-year TCO for most traction duties, not because it is cheaper per unit but because it eliminates watering labour, acid-mist ventilation and mid-life replacement. Model shown in §3: $2,290 vs $4,360 flooded vs $3,010 lithium, per 48V pack.
The three failure modes that matter are chronic undercharge (float below 13.2V on a 12V unit), mixing batteries of different ages in one string, and charging below 0°C. All three are specification and installation faults, not product faults.
CHISEN supplies factory-direct from 8 production bases with 70 GWh annual capacity, with CE / RoHS / REACH / MSDS / IMDG documentation and export packs prepared for 60+ destination markets.

§1 — The Published Specification Table

Every figure below is taken from the CHISEN 6-EVF-120 published datasheet, not from a category average.

Parameter	Specification
Model	6-EVF-120
Nominal voltage	12 V (6 cells × 2 V)
Rated capacity	120 Ah at C3 (3-hour rate, 1.75 V/cell cutoff)
Dimensions (L × W × H)	407 × 170 × 240 mm
Total height with terminals	240 mm
Weight	40.0 kg ± 0.2 kg
Terminal type	φ20-M8
Maximum charge current	24.0 A
Cycle life	350–600 cycles at 50–80% depth of discharge
Design life	2–5 years
Operating temperature	−15°C to 50°C
Storage temperature	−20°C to 45°C
Float charge voltage	13.5 V (2.25 V/cell)
Equalise charge voltage	14.1 V (2.35 V/cell)
Charge acceptance	≤ 4 hours to 80% state of charge
Self-discharge	≤ 3% per month at 25°C
Safety valve	10–49 kPa automatic regulation
Case material	ABS engineering plastic, flame-retardant V0 grade
Vibration resistance	GB/T 32620.1 compliant (3g, 2 hours)
Construction	Sealed VRLA / AGM, maintenance-free
Certifications	CE, RoHS, REACH, MSDS, IMDG (sea freight)
Application standard	GB/T 32620.1-2016 and GB/T 32620.2-2016 (lead-acid batteries for electric road vehicles)

What the “EVF” code actually tells you. In the CHISEN naming convention used across the EVF series, EV designates the electric-vehicle category defined in GB/T 32620 (electric road vehicles, as distinct from starting, traction-industrial or stationary duty), and F designates the valve-regulated sealed construction with an automatic pressure-relief valve. The trailing number is the amp-hour rating at the 3-hour rate. The leading digit is the cell count, which is where the nominal voltage comes from: 6-EVF-120 is 12V, 4-EVF-150 is 8V, 3-EVF-200 is 6V. If a supplier cannot explain this on a phone call, that is information about the supplier.

Where it fits in the EVF ladder. The 6-EVF-120 sits in the middle of the range — heavy enough for 1.5–2 ton forklifts, light enough for mid-size sightseeing vehicles, and the most common single unit in 48V packs.

Model	Voltage	Rate	Capacity	Dimensions (mm)	Weight	Terminal	Max charge current
3-EVF-200	6 V	C3	200 Ah	260 × 180 × 270	34.0 kg	φ20-M8	40.0 A
4-EVF-150	8 V	C3	150 Ah	260 × 180 × 280	34.8 kg	φ20-M8	30.0 A
6-EVF-60	12 V	C3	60 Ah	258 × 170 × 160	18.8 kg	φ14-M6	12.0 A
6-EVF-70	12 V	C3	70 Ah	259 × 170 × 210	23.3 kg	φ16-M6	—
6-EVF-80	12 V	C3	80 Ah	259 × 170 × 218	25.7 kg	φ16-M6	—
6-EVF-100	12 V	C3	100 Ah	330 × 170 × 218	31.5 kg	φ20-M8	—
6-EVF-120	12 V	C3	120 Ah	407 × 170 × 240	40.0 kg	φ20-M8	24.0 A
6-EVF-135	12 V	C3	135 Ah	338 × 172 × 280	45.0 kg	φ20-M8	—
6-EVF-150	12 V	C3	150 Ah	483 × 170 × 240	48.5 kg	φ20-M8	—

The published model pages for the individual series are the fastest way to confirm the exact variant that fits your battery box: 6-EVF-120 12V120Ah specifications → and the full EVF electric road vehicle series →.

§2 — The Pain: What Actually Breaks in a Traction Fleet

Most battery failures in traction duty are not manufacturing defects. They are duty-cycle failures, and they follow a pattern so consistent that experienced fleet engineers recognise it within weeks of the first handover.

The energy gap nobody priced in. The catalogue says 120Ah. The vehicle draws at C3 because it lifts, accelerates and climbs. At C3 the cell gives 120Ah; at C10 the same cell gives roughly 95–100Ah. Fleet managers who size on the nameplate and then run the pack to 80% depth of discharge are, in practice, running the pack at a 90–100% depth of discharge. Cycle life collapses. A cell rated for 350–600 cycles quietly delivers 180–250, and the failure arrives in year two rather than year four.

Undercharge in tropical operation. Float voltage on a 12V AGM unit should sit at 13.5 V at 25°C. Without temperature compensation, a charger holding 13.5 V in a 35°C yard drives the actual cell voltage below 13.2 V, which is chronic undercharge. Chronic undercharge causes sulphation, and sulphated lead-acid cannot be recovered — the plates are damaged permanently. This is the single most common cause of early failure in Mombasa, Dubai, Ho Chi Minh City, Chennai, Jakarta and Santos installations, and it is entirely a charger-configuration fault.

Weight, and what it does to the machine. A 48V pack of four 6-EVF-120 units weighs 160 kg. On a 1.5-ton forklift that is 11% of the rated capacity consumed by batteries before the operator climbs aboard. Pack sizing should therefore be evaluated against payload requirements, not just run-time requirements.

Acid mist, ventilation and the workshop. Flooded batteries in an enclosed charging bay generate hydrogen and acid mist. Jurisdictions then require forced ventilation, and many charging bays in practice have none — which corrodes terminals, damages chargers and creates a hydrogen accumulation risk in an enclosed space.

§3 — The Choice: AGM VRLA vs Flooded vs Lithium, Quantified

The table below models one realistic duty: 20 two-ton electric forklifts, 48V packs, two shifts per day, 300 operating days per year, 32°C average ambient, 5-year horizon. All figures are a transparent model, not a quotation — the assumptions are stated so you can rebuild the comparison with your own electricity tariff, labour rate and duty profile.

Cost line (5 years, per 48V / 120Ah pack)	Flooded lead-acid	AGM VRLA (4 × 6-EVF-120)	LFP 48V pack
Initial purchase	$560	$920	$2,150
Electricity over 5 years	$980	$860	$640
Watering and inspection labour	$620	$120	$60
Ventilation and cooling provision	$180	$90	$40
Replacement inside the 5-year window	$1,120	$0	$0
Battery-related downtime	$900	$300	$120
5-year total cost of ownership	$4,360	$2,290	$3,010

Read that table carefully — it is not a sales argument, it is a scenario. AGM wins this scenario by $720 per pack because it removes watering labour, acid-mist ventilation and one mid-life replacement. Across 20 trucks that is $14,400 saved over five years, which is why AGM remains the default for sealed traction packs.

Where the conclusion flips:

Flooded wins if you have a technician on site who can water cells every 3–6 months, a dedicated ventilated charging room, and a low duty cycle (one charge per day). The $620 labour line is what kills it; remove that and flooded is competitive again.
Lithium wins if weight reduction is worth money to you — aerial work platforms, marine applications, or trucks with a hard payload ceiling. A 48V 480Ah LFP pack is roughly 45% lighter than the AGM equivalent, and it removes the daily opportunity cost of charging windows.
Lithium also wins on labour availability. In markets where finding a technician willing to work on flooded acid batteries is hard, the labour line is understated. We have seen this matter repeatedly in West Africa and Central Asia.
Beyond roughly seven years, at rising energy tariffs and two-shift duty, lithium’s lower energy cost and zero replacement pull ahead. Below seven years, on traction duty, AGM is usually the lower-cost answer.

One further comparison that procurement teams overlook: usable energy at the real discharge rate.

Pack configuration	String capacity (C3)	Usable at 80% DoD	Nominal energy	Usable energy	Pack weight
4 × 6-EVF-120 (12 V)	120 Ah	96 Ah	5.76 kWh	4.61 kWh	160 kg
4 × 6-EVF-60 (12 V)	60 Ah	48 Ah	2.88 kWh	2.30 kWh	75 kg
6 × 4-EVF-150 (8 V)	150 Ah	120 Ah	7.20 kWh	5.76 kWh	209 kg
9 × 4-EVF-150 (8 V)	150 Ah	120 Ah	10.80 kWh	8.64 kWh	313 kg
6 × 6-DMF-52 (12 V)	52 Ah	42 Ah	3.74 kWh	3.00 kWh	82 kg

Every string above is wired in series, so its amp-hour rating equals that of a single unit — series wiring adds voltage, not capacity. All figures are C3 ratings. At a C10 duty the same packs deliver roughly 20–25% less.

§4 — The Framework: Seven Criteria Before You Issue a Purchase Order

1. Establish the real discharge rate, then the real capacity. Not the motor rating — the measured current draw during the heaviest part of the duty cycle. Lift a full load on a 10% gradient while the hydraulic pump runs, and measure. Then multiply by the required run time, add 25–30% margin, and select at that discharge rate.

2. Fix the pack voltage and the cell count explicitly. 6-EVF-120 is 12V. Four units in series = 48V; six = 72V; eight = 96V. Nine 12V units in series gives 108V, which is a different DC panel entirely. Write the configuration into the purchase order, not just “48V battery”.

3. Match the charger to the cell — and match the temperature compensation. Maximum charge current for the 6-EVF-120 is 24.0 A. A 30 A charger will overdrive it. The charger must also deliver temperature-compensated float at approximately −3 mV per °C per cell, and it must be programmed for the AGM profile (13.5 V float, 14.1 V equalise, 1.75 V/cell cutoff) rather than a flooded profile with a higher equalise setpoint.

4. Verify physical fit and the chassis load. 407 × 170 × 240 mm per unit, 40.0 kg, and 160 kg for a four-unit pack. Confirm the battery box dimensions, the tray’s load rating, the hold-down bracket spacing, the terminal clearance for the φ20-M8 stud, and the cable cross-section against 24 A charge and your peak discharge current. If the box is tight, the 6-EVF-120B at 338 × 172 × 280 mm and 41.6 kg exists for that reason.

5. Set a date-code rule and refuse mixed-age strings. All units in one pack should come from the same production batch and be no more than 3 months apart in date code. Put that in the purchase order and in the inspection checklist. It eliminates the most common cause of warranty disputes at no cost.

6. Demand the documentation before you commit. For the 6-EVF-120 the standard export pack is CE, RoHS, REACH, MSDS and IMDG sea-freight documentation, plus the certificate of origin and the GB/T 32620 conformity reference. If a destination requires SONCAP, PVOC, SASO, BIS or ESMA, ask who arranges it and at what lead time.

7. Plan the commissioning protocol before the batteries arrive. For factory-new or long-stored units, the first three charge cycles should run at least 10–12 hours each so the cells reach full capacity. Series strings must be voltage-matched before energising, insulation-protected, and connected by a technician. This is a five-minute procedure that prevents a disproportionate share of early failures.

§5 — The Trust Layer: What to Demand, and What to Verify

What CHISEN puts behind the product. CHISEN has manufactured lead-acid batteries since 2002, with 8 production bases and 70 GWh of annual capacity, producing across 2V, 6V, 8V and 12V from 4Ah to 3,000Ah in the DZF, DMF, FD, EVF, GFM, OPzV and OPzS series plus lithium. Export documentation covers 60+ destination markets, technical support runs in six languages with a 12-hour email response target, and sample units ship on request so you can run your own capacity test before committing to a full bank. Company details: about CHISEN Battery →.

The seven failure modes, root cause and prevention.

Failure mode	Root cause	Prevention
Sulphation from chronic undercharge	Float voltage below 13.2 V on a 12V unit, or missing temperature compensation	Verify charger float at 13.5 V and compensation at −3 mV/°C/cell at the controller, not only at the battery
Premature capacity fade	Pack sized on C10 nameplate but operated at C3	Size at the measured discharge rate; add 25–30% margin
Weak unit in a mixed-age string	Units of different production dates in one pack	Written date-code rule: same batch, maximum 3 months apart
Terminal corrosion and heating	Terminal torque below specification, loose interconnects	Torque every φ20-M8 terminal to specification at commissioning and re-torque annually
Thermal stress during charge	Charge in an enclosed, unventilated bay at high ambient temperature	Charge outdoors or in a ventilated bay; never charge a pack at 45°C or above
Capacity loss from deep discharge	Repeated running below the end voltage of 1.75 V/cell	Recharge at 20% remaining capacity; never leave a pack below 10% for more than 24 hours
Grid corrosion from deep discharge	Standing at low state of charge for long periods	Store at full charge, top up monthly, and re-check capacity before returning to service

Commissioning checklist — complete before the first load test.

Confirm every unit carries the same date code and the same batch, with no more than 3 months between units.
Measure and record open-circuit voltage for each unit. A spread wider than 0.05 V per cell across the pack needs an equalisation cycle before energising.
Torque every φ20-M8 terminal to specification and photograph the reading for each string. That photograph is the document that settles warranty arguments.
Verify the charger is on the AGM profile: 13.5 V float, 14.1 V equalise, 1.75 V/cell cutoff, maximum 24.0 A, with temperature compensation active.
Run three full charge cycles of at least 10–12 hours each on new or long-stored units before the vehicle enters service.
Log the baseline: per-unit voltage, ambient temperature, and the bay position of each pack. Without that baseline you cannot diagnose anything at month 18.

One thing about temperature that buyers consistently underestimate. The −15°C to 50°C operating range covers discharge and general use, but do not charge below 0°C. Lead-acid chemistry cannot absorb charge efficiently at sub-zero temperatures, and charging a cold pack risks freezing the electrolyte within the cell. In cold-climate operations, bring the pack to at least 5°C in a warm bay before charging, and keep the batteries on float rather than switching them off for the winter.

§6 — FAQ: 9 Questions Procurement Teams Ask Before Ordering

Q1. What does “6-EVF-120 12V120Ah” actually specify? A 12-volt sealed AGM (VRLA) deep-cycle battery with six 2-volt cells, rated at 120 amp-hours at the 3-hour rate, with a φ20-M8 terminal. The “6” is the cell count, “EV” denotes the electric-vehicle category under GB/T 32620, and “F” denotes the valve-regulated sealed construction.

Q2. Is the 120Ah rating C3 or C10, and how much does it matter? It is 120Ah at C3. At the 10-hour rate the same cell delivers approximately 95–100Ah — a 20–25% reduction caused by the Peukert effect, which is simply the physical reality that lead-acid delivers less energy when you pull it harder. Size the bank on your measured discharge rate and add 25–30% margin.

Q3. How many units do I need for a 48V system? Four units in series give 48V with a 120Ah string capacity at C3. Six units give 72V and eight give 96V — the string capacity stays at 120Ah in every case, because series wiring adds voltage and not amp-hours. A four-unit pack weighs 160 kg, which must be included in the chassis load calculation. For the pack options across the EVF range, see the EVF series specification pages →.

Q4. Can I mix 6-EVF-120 units with other EVF models in one pack? Technically you can build a pack from different models, but do not do it with units of different ages or different capacities in the same string series — the weakest unit sets the string limit and cycles down first. A better approach for a mixed requirement is to use 12V units throughout a 48V string and size the pack with more units of a smaller capacity rather than fewer units of a larger capacity.

Q5. What charger do I need? One sized to a maximum of 24.0 A for this cell — a 20–24 A charger is the correct range. The charger must be configured for the AGM profile (13.5 V float, 14.1 V equalise, 1.75 V/cell cutoff) and must include temperature compensation of roughly −3 mV per °C per cell. A flooded-profile charger on an AGM pack will over-charge and shorten life.

Q6. What is the realistic service life in a hot climate? The published figure is 350–600 cycles at 50–80% depth of discharge, or a 2–5 year design life. In a 32–38°C ambient with correct float voltage and compensation, plan on the lower half of that range. In a ventilated, temperature-controlled bay with disciplined charging, the upper half is achievable. Ambient temperature, not the calendar, decides how fast those cycles arrive.

Q7. How do I ship these — can they go by air? Sealed AGM batteries are considerably easier to ship than flooded cells because there is no free electrolyte. They are supplied with MSDS, a land and sea transport report, and a certificate of origin, and are handled under the UN2794 dangerous-goods framework. Air freight is generally possible with the correct documentation; confirm with your forwarder before booking.

Q8. Is 6-EVF-120 suitable for solar storage or a telecom DC plant? Not as the primary choice. The EVF series is engineered for high-rate traction discharge — which is exactly the opposite profile to a slow, deep stationary discharge. For telecom DC panels, data-centre UPS, railway signalling or solar storage, specify the stationary tubular families instead: OPzS for flooded tubular with the longest float life, or OPzV for sealed tubular gel where the site is unmanned.

Q9. What do I need to send for a quotation? Send the pack voltage, the number of units per pack, your measured discharge current and required run time, the daily cycle count, the worst-case ambient temperature, the charger you already own (so we can confirm compatibility), and the destination country for documentation. We return a complete sizing sheet and quotation within 24 hours, and sample units are available so you can run your own capacity test before you commit to a full bank.

Expert Summary

For industrial buyers evaluating the 6-EVF-120 12V120Ah, the decisive facts are these. It is a 12-volt, six-cell, fully sealed AGM (VRLA) deep-cycle battery rated at 120 amp-hours at the three-hour rate, built to GB/T 32620.1-2016 and GB/T 32620.2-2016 for electric road vehicles, with a published footprint of 407 × 170 × 240 mm, a weight of 40.0 kg, a φ20-M8 terminal and a maximum charge current of 24.0 A. Rated cycle life is 350–600 cycles at 50–80% depth of discharge with a 2–5 year design life across a −15°C to 50°C operating range; float is 13.5 V, equalise 14.1 V, cutoff 1.75 V per cell, and self-discharge is no more than 3% per month at 25°C. Four units in series form a 48V traction pack with a 120Ah string capacity, weighing 160 kg; six form 72V and eight form 96V, both still at 120Ah because series wiring adds voltage and not capacity. The decisive engineering point is that the 120Ah figure is a three-hour-rate rating: at C10 the same cell yields only about 95–100Ah, so a pack sized on the nameplate and operated at C3 runs at effectively 90–100% depth of discharge and collapses cycle life to roughly 180–250 cycles. In a modelled two-shift, 20-truck fleet at 32°C ambient, the five-year total cost of ownership per 48V pack is approximately $2,290 for AGM VRLA against $4,360 for flooded lead-acid and $3,010 for LFP, the AGM advantage coming from eliminated watering labour, acid-mist ventilation and mid-life replacement rather than from unit price. Three specification faults account for most premature failures — chronic undercharge from a charger without temperature compensation, mixed production dates within a single string, and charging below 0°C — and all three are eliminated by a written date-code rule, a correctly configured charger and a commissioning protocol. CHISEN supplies the 6-EVF-120 factory-direct from 8 production bases with 70 GWh of annual capacity, CE / RoHS / REACH / MSDS / IMDG documentation prepared for 60+ destination markets, and free engineering sizing returned within 24 hours.

Contact CHISEN — 24-Hour Response

CHISEN Battery — 20+ years manufacturing lead-acid batteries, exporting to 60+ countries from 8 production bases with 70 GWh annual capacity.

Email: sales@chisen.cn — full quotation and sizing table within 24 hours
Phone / WhatsApp: +86 131 6622 6999
WhatsApp: https://wa.me/8613166226999
Model page: https://www.chisen.cn/en/6-EVF-120/12V120Ah.html

Send us pack voltage + units per pack + measured discharge current + daily cycles + worst-case ambient temperature + destination country, and our engineering team returns a complete sizing sheet — cell count, capacity margin, charger profile, temperature derating and documentation scope — within one working day. Sample units are available on request for your own capacity test before you commit to a full bank.

Full product range and current production data: https://www.leadacidbattery.cn

Published by CHISEN Battery. Standard data per CHISEN 6-EVF-120 published datasheet, GB/T 32620.1-2016 and GB/T 32620.2-2016. TCO figures are a stated-assumption model for comparison, not a quotation. Availability, certification and destination-specific approvals confirmed on request.

Related CHISEN Buyer Guides

October 23, 2026

6-DMF-52 12V52Ah VRLA Battery: E-Tricycle Sizing and TCO

Reading time: 19 minutes | For: e-mobility importers and distributors, electric tricycle and motorcycle OEMs, fleet operators, and aftermarket battery distributors across India, Bangladesh, Kenya, Nigeria, South-East Asia, Latin America and the Middle East

Answer First

The 6-DMF-52 12V52Ah is a 12-volt, 52 amp-hour sealed VRLA / AGM deep-cycle battery purpose-built for electric tricycles, electric motorcycles and electric mopeds. Six 2V cells in series give the full 12V, the 52Ah rating is at the 3-hour rate (C3), and the whole pack is maintenance-free for its entire life — no watering, no acid checks, no spill risk in a vehicle that tilts, jolts and vibrates all day.

Five numbers decide the procurement:

52Ah at C3, which is the rate an e-tricycle actually runs at. The same cell yields roughly 44–46Ah at C10 — a 15–20% gap that matters if you size the pack on the nameplate and then run it flat.
224 × 135 × 175 mm at 13.7 kg. A 48V four-unit pack is 54.8 kg, a 72V six-unit pack is 82.2 kg. On a cargo tricycle carrying 500–800 kg of payload, every kilogram of battery is a kilogram of revenue lost.
10.4 A charging current (0.2C) — the charger must be matched to this figure and set to the VRLA profile, or the pack will be chronically undercharged or overcharged.
350–600 cycles at 50–80% depth of discharge and a 2–5 year design life; e-tricycle packs are usually replaced every 12–24 months, so that cycle figure is what sets your replacement schedule.
Built to T/ZJXDC 002-2022, the Chinese industry group standard for valve-regulated lead-acid batteries used in electric motorcycles and mopeds, alongside JB/T 2599-2012 for model designation and GB/T 32620.1-2016 for vibration and dynamic durability. This is the compliance line to ask a supplier for.

The honest caveat: the 6-DMF-52 is a 3-hour-rate cell. If you are building a light e-bike or a low-speed passenger tricycle that runs a shallower discharge, the 2-hour-rate DZF series is the better match — using a DMF cell in that duty shortens its life. The DMF-versus-DZF distinction is not a product-name label; it is a discharge-rate decision, and it is covered in §4.

Key Takeaways

6-DMF-52 = 12V (6 cells), 52Ah at C3, 224 × 135 × 175 mm, 13.7 kg, φ11.8-M6 terminal, 10.4 A charge current. Published figure.
Pack math: 4 units = 48V, 5 = 60V, 6 = 72V — each with a 52Ah string capacity, because series wiring adds voltage and not amp-hours. 48V suits 500–800 kg payload tricycles; 72V suits heavy freight and steep grades.
Never confuse the DMF and DZF series. DMF is rated at C3 (motorcycle and tricycle duty), DZF at C2 (e-bike duty). Substituting one for the other in a high-current application is the most common cause of early warranty claims.
AGM wins on 4-year TCO for e-tricycle fleets by a wide margin, because it eliminates watering labour, acid-mist ventilation and mid-life replacement. Model shown in §3: $1,360 per 48V pack, against $3,260 flooded and $1,650 lithium.
The three killer faults are chronic undercharge from a charger with no temperature compensation, mixed production dates in one pack, and charging a cold pack below 0°C. All three are installation faults, not product faults.
CHISEN supplies factory-direct from 8 production bases with 70 GWh annual capacity, shipping 6-DZF / 6-DMF / 6-EVF series with CE / RoHS / REACH / MSDS / IMDG documentation to 60+ destination markets, and 100,000+ units of ready stock on the mainstream models.

§1 — The Published Specification Table

Every figure below comes from the CHISEN 6-DMF-52 published datasheet, not from a category average.

Parameter	Specification
Model	6-DMF-52
Nominal voltage	12 V (6 cells × 2 V)
Rated capacity	52 Ah at C3 (3-hour rate, 1.75 V/cell cutoff)
Dimensions (L × W × H)	224 × 135 × 175 mm
Total height with terminals	175 mm
Weight	13.7 kg ± 0.2 kg
Terminal configuration	φ11.8-M6
Charging current	10.4 A
Cycle life	350–600 cycles at 50–80% depth of discharge
Design life	2–5 years
Float charge voltage	13.5 V (2.25 V/cell)
Equalise charge voltage	14.1 V (2.35 V/cell)
Cutoff voltage	1.75 V per cell
Charge acceptance	≤ 4 hours to 80% state of charge
Self-discharge	≤ 3% per month at 25°C
Working temperature	−15°C to 50°C
Storage temperature	−20°C to 45°C
Safety valve	10–49 kPa automatic regulation
Case material	ABS engineering plastic, flame-retardant V0 grade
Vibration resistance	GB/T 32620.1 compliant (3g for 2 hours)
Battery type	Valve-regulated lead-acid (VRLA), AGM technology
Standards	T/ZJXDC 002-2022, JB/T 2599-2012, GB/T 32620.1-2016
Certifications	CE, RoHS, REACH, MSDS, IMDG (sea freight), cadmium-free and mercury-free
Applications	Electric tricycles, electric motorcycles, electric mopeds, electric sightseeing vehicles

What the model code tells you. In the CHISEN naming convention, the leading 6 is the cell count (six 2V cells in series, hence 12V). D denotes the electric-vehicle design. M denotes motorcycle duty — the plate and terminal design optimised for the high-rate discharge and repeated start-stop behaviour of electric motorcycles and mopeds. F denotes valve-regulated construction, with a one-way safety valve that opens between 10 and 49 kPa so internal pressure self-regulates without leaking. The trailing 52 is the amp-hour rating at the 3-hour rate. Together, DMF is the industry-standard identifier for a valve-regulated battery built for electric motorcycle and tricycle duty.

Where the 6-DMF-52 sits in its own series.

Model	Voltage	Rate	Capacity	Dimensions (mm)	Weight	Terminal
6-DZF-20	12 V	C2	20 Ah	180 × 76 × 170	6.1 kg	φ8.8-M5
6-DMF-32	12 V	C3	32 Ah	224 × 93 × 175	9.15 kg	φ8.8-M5
6-DMF-38	12 V	C3	38 Ah	224 × 106 × 175	10.45 kg	φ9.8-M5
6-DMF-45	12 V	C3	45 Ah	224 × 121 × 175	12.3 kg	φ11.8-M5
6-DMF-52	12 V	C3	52 Ah	224 × 135 × 175	13.7 kg	φ11.8-M6
6-DMF-58	12 V	C3	58 Ah	230 × 151 × 175	15.4 kg	φ11.8-M6

Note the 224 mm length and 175 mm height are constant across the 32–52Ah range: they share the same case series, which is why a distributor can offer three capacities in one tray footprint. The 6-DMF-58 changes both width and length, so it needs its own tray.

Pack configurations from the same cell.

Configuration	Units in series	Nominal voltage	String capacity (C3)	Nominal energy	Usable energy at 80% DoD	Pack weight
Light city	4 × 6-DMF-52	48 V	52 Ah	2,496 Wh	1,997 Wh	54.8 kg
Mid duty	5 × 6-DMF-52	60 V	52 Ah	3,120 Wh	2,496 Wh	68.5 kg
Heavy freight	6 × 6-DMF-52	72 V	52 Ah	3,744 Wh	2,995 Wh	82.2 kg
Light three-wheeler	4 × 6-DMF-32	48 V	32 Ah	1,536 Wh	1,229 Wh	36.6 kg
Heavy three-wheeler	4 × 6-DMF-58	48 V	58 Ah	2,784 Wh	2,227 Wh	61.6 kg

Every string above is wired in series, so its amp-hour rating equals that of a single unit — series wiring adds voltage, not capacity. All figures are C3 ratings; at a C10 duty the same packs deliver roughly 15–20% less. Individual model pages confirm the exact variant and terminal geometry for your tray: 6-DMF-52 12V52Ah specifications → and the DZF / DMF electric vehicle battery range →.

§2 — The Pain: Where E-Tricycle Batteries Actually Fail

Across two decades of supplying e-mobility markets in South Asia, South-East Asia, Africa and Latin America, the same four failure patterns account for the overwhelming majority of field returns. None of them is a manufacturing defect.

The DMF-versus-DZF mismatch. A distributor stocks one cell and sells it into both light e-bikes and heavy tricycles. The DZF series is a 2-hour-rate cell; the DMF series is a 3-hour-rate cell with a heavier plate and terminal designed for motorcycle duty. Put a DZF cell into a tricycle drawing hard current and it will deliver the right amp-hours on the bench and disappoint in the field — higher internal resistance, more voltage drop under load, fewer cycles. The reverse mistake — fitting a DMF cell into a light e-bike — costs money in unused capacity and weight, but does not kill the cell. Always match the series to the duty.

Undercharge in a hot charging bay. Float on a 12V VRLA unit should sit at 13.5 V at 25°C. Chargers without temperature compensation hold 13.5 V into a 38°C bay, which drives the actual cell voltage below 13.2 V. Sustained undercharge causes sulphation, and sulphated plates cannot be recovered. In Chennai, Ho Chi Minh City, Jakarta, Lagos and Salvador this is the number one cause of packs dying in their second year.

Weight versus payload on a cargo tricycle. A 48V pack of four 6-DMF-52 units weighs 54.8 kg. A cargo tricycle rated for 500–800 kg of payload can carry only about 700 kg including rider, vehicle mass and batteries. Every kilogram of battery is directly a kilogram of payload you cannot sell. On a 72V six-unit pack at 82.2 kg, the battery now represents more than 10% of the vehicle’s gross mass — which is why tricycle OEMs increasingly specify a lighter 6-DMF-38 or 6-DMF-45 rather than the largest cell that will physically fit.

§3 — The Choice: VRLA vs Flooded vs Lithium, Quantified

The table below models a realistic duty: 60 electric cargo tricycles, 48V packs, one full discharge cycle per day, 300 operating days per year, 32°C average ambient, four-year horizon. All figures are a stated-assumption model so you can rebuild it with your own tariff, labour rate and duty profile — not a quotation.

Cost line (4 years, per 48V / 52Ah pack)	Flooded lead-acid	AGM VRLA (4 × 6-DMF-52)	LFP 48V / 208Ah
Initial purchase	$430	$560	$1,180
Electricity over 4 years	$520	$470	$340
Watering and inspection labour	$760	$90	$40
Acid-mist ventilation provision	$150	$60	$30
Replacement inside the 4-year window	$860	$0	$0
Breakdown and downtime	$540	$180	$60
4-year total cost of ownership	$3,260	$1,360	$1,650

The $1,900 gap per pack is almost entirely labour. Flooded cells need a technician to travel to the vehicle, check levels, top with distilled water and manage corrosion. In a scattered fleet across a city, that service visit is the dominant cost — and it is the cost that decides the business case in markets where service coverage is thin. Across 60 vehicles, the difference is $114,000 over four years.

Where the conclusion changes:

Flooded wins only where vehicles return to a central workshop daily, a technician already exists on the payroll, and that labour is not charged to the battery. In that specific case the $760 labour line collapses and flooded becomes competitive.
Lithium wins where weight is the binding constraint — a tricycle with a hard payload ceiling, an aircraft ground-support application, or a marine deployment — and where the up-front premium can be amortised over a five-year-plus horizon. On a four-year, one-cycle-per-day duty, lithium is still $290 more expensive per pack than VRLA despite far lower energy cost.
Lithium also wins on cycle life in principle. Where the duty is two cycles per day rather than one, the gap narrows and lithium pulls ahead by year five.

The dimension comparison that decides most e-tricycle builds. Both batteries occupy the same class of space; the differences that matter in a tricycle are weight and terminal geometry.

Attribute	6-DMF-52 (AGM VRLA)	Equivalent flooded cell	LFP 48V module
Pack mass for 48V / ~52Ah	54.8 kg	~62 kg	~32 kg
Maintenance	None	Water every 3–6 months	None
Installation	Any orientation except inverted	Upright only	Any orientation
Leakage risk	Sealed	Acid spill risk in a tilting vehicle	Sealed
Acid mist	None	Yes — needs ventilation in the charging bay	None
Self-discharge	≤ 3% per month at 25°C	≥ 10% per month	~3% per month
Cycle life	350–600 at 50–80% DoD	200–300	2,000+

§4 — The Framework: Six Criteria Before You Issue a Purchase Order

1. Match the series to the duty, not just the capacity. DMF is the 3-hour-rate series for electric motorcycles, mopeds and tricycles. DZF is the 2-hour-rate series for lighter e-bike applications. If the vehicle pulls sustained high current under load and does frequent starts, specify DMF.

2. Fix the pack voltage and the cell count in writing. 4 × 6-DMF-52 = 48V with a 52Ah string capacity, for passenger tricycles and typical 500–800 kg cargo duty. 5 units = 60V for heavier freight or 1–2 ton payloads on moderate grades. 6 units = 72V for steep terrain, long routes and the best hill-climbing performance. In every configuration the string capacity stays at 52Ah — series wiring adds voltage and not amp-hours. Write “48V, 4 × 6-DMF-52” into the order, not “52Ah battery”.

3. Size the pack against the route, with a margin. Published range for a 48V four-unit pack is 70–110 km per cycle depending on payload, road surface and gradient. Every additional 100 kg of payload costs roughly 10–15% of range. Reserve capacity at daily distance × 1.5, then check the pack against the discharge rate you actually see in the field.

4. Match the charger, and turn on temperature compensation. Maximum charging current for the 6-DMF-52 is 10.4 A. The charger must be on the VRLA profile: 13.5 V float, 14.1 V equalise, 1.75 V per cell cutoff, with approximately −3 mV per °C per cell compensation. A charger in a flooded profile will over-charge a VRLA pack and shorten its life; a charger with no compensation will under-charge it in a hot bay.

5. Write the date-code rule into the purchase order. All four units of a pack should share one production batch and be no more than three months apart in date code. It costs nothing and it removes the most common cause of warranty disputes on e-mobility packs.

6. Plan the charging infrastructure before you order the batteries. The single biggest operational failure in e-tricycle fleets is charging: too few chargers, chargers shared between vehicles that need them at the same time, chargers with no temperature compensation, and chargers located where the vehicle must be parked overnight. Specify the charger count, the cycle time, the ventilation and the location before the pack arrives, not after.

§5 — The Trust Layer: What to Demand, and What to Verify

What CHISEN puts behind the product. CHISEN has manufactured lead-acid batteries since 2002, with 8 production bases and 70 GWh of annual capacity across 2V, 6V, 8V and 12V, from 4Ah to 3,000Ah, in the DZF, DMF, FD, EVF, GFM, OPzV and OPzS series plus lithium. Over 100,000 units of the mainstream 6-DZF / 6-DMF / 6-EVF series are held as ready stock for immediate shipment. Export documentation covers 60+ destination markets with MSDS, transport report, certificate of origin and quality inspection report prepared for customs clearance, and technical support runs in Chinese, English, Japanese, Spanish, Arabic and Russian with a 12-hour email response target. Company details: about CHISEN Battery →.

The seven failure modes, root cause and prevention.

Failure mode	Root cause	Prevention
Sulphation from chronic undercharge	Float below 13.2 V on a 12V unit, or no temperature compensation	Verify charger float at 13.5 V and compensation at −3 mV/°C/cell at the controller, not only at the battery
Premature capacity fade	DMF cell used in a C2 e-bike duty, or pack sized on nameplate alone	Match the series to the measured discharge rate; add 25–30% margin
Weak unit in a mixed-age pack	Units of different production dates in one string	Written date-code rule: same batch, maximum three months apart
Terminal corrosion and heating	Terminal torque below specification, loose interconnects	Torque every φ11.8-M6 terminal to specification at commissioning and re-torque annually
Thermal stress during charge	Charge in an enclosed, unventilated bay at high ambient	Charge outdoors or in a ventilated bay; never charge a pack above 45°C
Capacity loss from deep discharge	Repeated running below the 1.75 V per cell cutoff	Recharge at 20% remaining capacity; never leave a pack below 10% for more than 24 hours
Grid corrosion from deep discharge	Standing at low state of charge for long periods	Store at full charge, top up monthly, and re-check capacity before returning to service

Commissioning checklist — complete before the first load test.

Confirm every unit in the pack carries the same date code and batch, with no more than three months between units.
Measure and record open-circuit voltage for each unit. A spread wider than 0.05 V per cell across the pack needs an equalisation cycle before the pack goes into a vehicle.
Torque every φ11.8-M6 terminal to specification and photograph the reading for each pack. That photograph settles warranty arguments.
Verify the charger is on the VRLA profile: 13.5 V float, 14.1 V equalise, 1.75 V per cell cutoff, maximum 10.4 A, temperature compensation active.
Run three full charge cycles of at least 10–12 hours each on new or long-stored units so the cells reach full capacity.
Log the baseline: per-unit voltage, ambient temperature, and vehicle. Without that baseline you cannot diagnose anything at month 18.

One thing about temperature that buyers consistently underestimate. The −15°C to 50°C operating range covers discharge and general use, but do not charge below 0°C. Lead-acid chemistry cannot absorb charge efficiently at sub-zero temperatures, and charging a cold pack risks freezing the electrolyte inside the cell. In cold-climate operation, bring the pack to at least 5°C in a warm bay before charging and keep the batteries on float rather than switching them off for the winter.

§6 — FAQ: 9 Questions E-Mobility Buyers Ask Before Ordering

Q1. What does “6-DMF-52 12V52Ah” mean? A 12-volt sealed VRLA (AGM) deep-cycle battery with six 2V cells, rated at 52 amp-hours at the 3-hour rate, with a φ11.8-M6 terminal. The “6” is the cell count, “DMF” denotes the electric-vehicle, motorcycle-duty, valve-regulated construction series, and “52” is the amp-hour rating at C3.

Q2. Is the 52Ah rating at C3 or C10, and how much does it matter? It is 52Ah at C3, the rate an e-tricycle actually discharges at. At the 10-hour rate the same cell delivers approximately 44–46Ah. Size on your measured duty rate and add 25–30% margin, otherwise the pack is effectively being cycled at 90–100% depth of discharge and cycle life drops well below the published 350–600 cycles.

Q3. How many units do I need, and which pack voltage? Four units in series give 48V for passenger tricycles and 500–800 kg cargo duty, five units give 60V for 1–2 ton freight, and six units give 72V for steep terrain and long routes. The string capacity is 52Ah in every configuration, because series wiring adds voltage and not amp-hours. The pack weight is 54.8 kg, 68.5 kg and 82.2 kg respectively, so the voltage choice is partly a payload decision.

Q4. Can I use a 6-DZF cell instead, or mix series? Do not use DZF where the duty is motorcycle or tricycle: DZF is a 2-hour-rate cell and will not deliver the required high-rate performance, which shows up as voltage drop, reduced range and shortened life. Do not mix DZF and DMF units in one pack either. If your duty spans both light e-bike and heavy tricycle applications, stock both series but keep them in separate packs.

Q5. What charger do I need? One rated at a maximum of 10.4 A for this cell, configured for the VRLA profile: 13.5 V float, 14.1 V equalise, 1.75 V per cell cutoff, with temperature compensation of approximately −3 mV per °C per cell. A flooded-profile charger will over-charge the pack; a charger without compensation will under-charge it in a hot bay.

Q6. What is the realistic service life in a tropical climate? The published figure is 350–600 cycles at 50–80% depth of discharge, or a 2–5 year design life. In practice, e-tricycle packs running one deep cycle a day are typically replaced every 12–24 months. With correct float voltage, temperature compensation and a date-code discipline, most of the life you paid for is delivered.

Q7. Can I ship these by air? Yes — sealed VRLA cells carry no free electrolyte and are considerably easier to ship than flooded batteries. The standard export pack includes MSDS, a land and sea transport report, and certificate of origin, and lead-acid batteries are handled under the UN2794 dangerous-goods framework. Confirm the documentation requirements with your forwarder before booking.

Q8. Is the 6-DMF-52 suitable for solar storage or a telecom DC panel? Not as the primary choice. The DMF series is engineered for high-rate traction discharge, the opposite of a slow stationary discharge. For telecom DC panels, data-centre UPS, railway signalling or solar storage, specify the stationary tubular families — OPzS flooded tubular for the longest float life, or OPzV sealed tubular gel for unmanned sites.

Q9. What do I need to send for a quotation? Send the pack voltage, the number of units per pack, the vehicle type and payload, the measured discharge current and required route length, the daily cycle count, the worst-case ambient temperature, the charger you already own, and the destination country for documentation. We return a complete sizing sheet and quotation within 24 hours, and sample units are available so you can run your own capacity test before committing to a full bank.

Expert Summary

For e-mobility importers and fleet operators evaluating the 6-DMF-52 12V52Ah, the decisive facts are these. It is a 12-volt, six-cell, fully sealed VRLA (AGM) deep-cycle battery rated at 52 amp-hours at the three-hour rate, built to T/ZJXDC 002-2022, JB/T 2599-2012 and GB/T 32620.1-2016, with a published footprint of 224 × 135 × 175 mm, a weight of 13.7 kg, a φ11.8-M6 terminal and a charging current of 10.4 A. Rated cycle life is 350–600 cycles at 50–80% depth of discharge with a 2–5 year design life across a −15°C to 50°C operating range; float is 13.5 V, equalise 14.1 V, cutoff 1.75 V per cell, and self-discharge is no more than 3% per month at 25°C. Four units in series form a 48V pack with a 52Ah string capacity weighing 54.8 kg, five give 60V and six give 72V, both still at 52Ah because series wiring adds voltage and not capacity. The decisive engineering point is that the 52Ah figure is a three-hour-rate rating: at C10 the same cell yields only about 44–46Ah, and the DMF series is engineered for that discharge profile while the two-hour-rate DZF series is not a substitute. In a modelled 60-vehicle, one-cycle-per-day cargo tricycle fleet at 32°C ambient, the four-year total cost of ownership per 48V pack is approximately $1,360 for VRLA AGM against $3,260 for flooded lead-acid and $1,650 for LFP, the VRLA advantage coming almost entirely from eliminated watering and service-visit labour rather than from unit price. Three installation faults cause most premature failures — chronic undercharge from a charger without temperature compensation, mixed production dates within a single pack, and charging a pack below 0°C — and all three are eliminated by a written date-code rule, a correctly configured charger and a commissioning protocol. CHISEN supplies the 6-DMF-52 factory-direct from 8 production bases with 70 GWh of annual capacity, over 100,000 units of ready stock on the mainstream 6-DZF / 6-DMF / 6-EVF series, CE / RoHS / REACH / MSDS / IMDG documentation prepared for 60+ destination markets, and free engineering sizing returned within 24 hours.

Contact CHISEN — 24-Hour Response

CHISEN Battery — 20+ years manufacturing lead-acid batteries, exporting to 60+ countries from 8 production bases with 70 GWh annual capacity.

Email: sales@chisen.cn — full quotation and sizing table within 24 hours
Phone / WhatsApp: +86 131 6622 6999
WhatsApp: https://wa.me/8613166226999
Model page: https://www.chisen.cn/en/6-DMF-52/12V52Ah.html

Send us pack voltage + units per pack + vehicle type and payload + measured discharge current + daily cycles + worst-case ambient temperature + destination country, and our engineering team returns a complete sizing sheet — cell count, capacity margin, charger profile, temperature derating and documentation scope — within one working day. Sample units are available on request for your own capacity test before you commit to a full bank.

Full product range and current production data: https://www.leadacidbattery.cn

Published by CHISEN Battery. Standard data per CHISEN 6-DMF-52 published datasheet, T/ZJXDC 002-2022, JB/T 2599-2012 and GB/T 32620.1-2016. TCO figures are a stated-assumption model for comparison, not a quotation. Availability, certification and destination-specific approvals confirmed on request.

Related CHISEN Buyer Guides

October 23, 2026

4-EVF-150 8V150Ah Battery: Pack Sizing and 5-Year Fleet TCO

Reading time: 19 minutes | For: resort and golf-course fleet managers, electric sightseeing vehicle operators, industrial logistics buyers, floor-scrubber and AGV OEMs, and distributors serving South-East Asia, the Middle East, Europe and the Americas

Answer First

The 4-EVF-150 8V150Ah is an 8-volt, 150 amp-hour sealed VRLA / AGM deep-cycle battery built for electric road vehicles and industrial equipment: 4–8 seat sightseeing vehicles, golf carts, 1–3 ton electric forklifts and stackers, floor scrubbers and sweepers, automated guided vehicles, and electric boats. Four 2V cells make the 8V block, so six units in series give a complete 48V traction pack.

Five numbers decide the procurement:

150Ah at the 3-hour rate (C3). At C10 the same cell delivers roughly 125–132Ah. A quotation showing “150Ah” without a rate is concealing a 12–17% gap between nameplate and usable energy.
260 × 180 × 280 mm at 34.8 kg. A six-unit 48V pack weighs 209 kg; a nine-unit 72V pack weighs 313 kg. On a sightseeing vehicle that already carries six passengers, that mass is the difference between a comfortable ride and a sluggish one.
30.0 A charging current (0.2C) — a 40 A charger is over-sized for this cell and will drive excess heat and voltage.
350–600 cycles at 50–80% depth of discharge, a 2–5 year design life, and a −15°C to 50°C operating range.
6–8 hours of continuous operation per charge in a 48V six-unit configuration, which is the working day most resort and course operations target.

The honest caveat: the 4-EVF-150 is not automatically the right unit for every 48V pack. Six 8V blocks of 150Ah is heavier than four 12V blocks of 120Ah, and lighter in capacity terms than eight 6V blocks of 200Ah. The right answer depends on whether you are optimising for payload, for range, or for the number of spare units you must hold. §3 quantifies all three.

Key Takeaways

4-EVF-150 = 8V (4 cells), 150Ah at C3, 260 × 180 × 280 mm, 34.8 kg, φ20-M8 terminal, 30.0 A charge current. Published figure.
Pack math: 6 units = 48V, 8 units = 64V, 9 units = 72V — string capacity stays at 150Ah in every case, because series wiring adds voltage and not amp-hours.
The unit-count decision has a hidden logistics cost. A 48V pack of six units means one spare covers 17% of the fleet; a pack of four means 25%; a pack of eight means 12.5%. Resale, service and depot stocking all inherit that ratio.
AGM wins on 5-year TCO for resort and course fleets, because it removes watering labour, acid-mist ventilation and mid-life replacement. Model shown in §3: $3,240 per 48V string against $6,230 flooded and $3,540 lithium.
Two faults dominate field returns: chronic undercharge from a charger without temperature compensation, and packs assembled from mixed production dates. Both are free to prevent at the purchasing stage.
CHISEN supplies factory-direct from 8 production bases with 70 GWh annual capacity, with CE / RoHS / REACH / MSDS / IMDG documentation prepared for 60+ destination markets, and multilingual technical support in six languages.

§1 — The Published Specification Table

Every figure below is taken from the CHISEN 4-EVF-150 published datasheet.

Parameter	Specification
Model	4-EVF-150
Nominal voltage	8 V (4 cells × 2 V)
Rated capacity	150 Ah at C3 (3-hour rate, 1.75 V/cell cutoff)
Dimensions (L × W × H)	260 × 180 × 280 mm
Total height with terminals	285 mm
Weight	34.8 kg ± 0.2 kg
Terminal configuration	φ20-M8
Charging current	30.0 A
Cycle life	350–600 cycles at 50–80% depth of discharge
Design life	2–5 years
Float charge voltage	9.0 V (2.25 V/cell)
Equalise charge voltage	9.4 V (2.35 V/cell)
Cutoff voltage	1.75 V per cell
Charge acceptance	≤ 4 hours to 80% state of charge
Self-discharge	≤ 3% per month at 25°C
Working temperature	−15°C to 50°C
Storage temperature	−20°C to 45°C
Safety valve	10–49 kPa automatic regulation
Case material	ABS engineering plastic, flame-retardant V0 grade
Vibration resistance	GB/T 32620.1 compliant (3g for 2 hours)
Battery type	Valve-regulated lead-acid (VRLA), AGM technology
Standards	GB/T 32620.1-2016, GB/T 32620.2-2016, JB/T 2599
Certifications	CE, RoHS, REACH, MSDS, IMDG (sea freight), cadmium-free and mercury-free
Applications	Sightseeing vehicles, golf carts, electric forklifts, floor scrubbers, AGVs, electric boats

What the model code tells you. The leading 4 is the cell count — four 2V cells in series give 8V. EV is the electric-vehicle category defined in GB/T 32620 for lead-acid batteries used as the main power source in electric road vehicles, as distinct from starting, stationary or traction-industrial duty. F denotes valve-regulated construction, with a one-way safety valve that opens between 10 and 49 kPa so internal pressure self-regulates without leaking. The trailing 150 is the amp-hour rating at the three-hour rate. A supplier who cannot decode the model number on a phone call is telling you something useful about their technical support.

Where the 4-EVF-150 sits across the EVF voltage range. This is the point at which most mistakes happen, so the full ladder is worth keeping on file.

Model	Voltage	Rate	Capacity	Dimensions (mm)	Weight	Terminal	Max charge current
3-EVF-200	6 V	C3	200 Ah	260 × 180 × 270	34.0 kg	φ20-M8	40.0 A
4-EVF-150	8 V	C3	150 Ah	260 × 180 × 280	34.8 kg	φ20-M8	30.0 A
6-EVF-60	12 V	C3	60 Ah	258 × 170 × 160	18.8 kg	φ14-M6	12.0 A
6-EVF-70	12 V	C3	70 Ah	259 × 170 × 210	23.3 kg	φ16-M6	—
6-EVF-80	12 V	C3	80 Ah	259 × 170 × 218	25.7 kg	φ16-M6	—
6-EVF-100	12 V	C3	100 Ah	330 × 170 × 218	31.5 kg	φ20-M8	—
6-EVF-120	12 V	C3	120 Ah	407 × 170 × 240	40.0 kg	φ20-M8	24.0 A
6-EVF-135	12 V	C3	135 Ah	338 × 172 × 280	45.0 kg	φ20-M8	—
6-EVF-150	12 V	C3	150 Ah	483 × 170 × 240	48.5 kg	φ20-M8	—

Note the deliberate overlap: the 4-EVF-150 and the 3-EVF-200 share almost identical footprints, 260 × 180 mm, with a 10 mm height difference. A battery tray designed for one can often accept the other, which is useful when a fleet transitions between vehicle types.

Pack configurations and what they cost in mass.

Configuration	Units in series	Nominal voltage	String capacity (C3)	Nominal energy	Usable energy at 80% DoD	Pack weight
Sightseeing vehicle	6 × 4-EVF-150 (8 V)	48 V	150 Ah	7.20 kWh	5.76 kWh	209 kg
Forklift, mid	8 × 4-EVF-150 (8 V)	64 V	150 Ah	9.60 kWh	7.68 kWh	278 kg
Forklift, heavy	9 × 4-EVF-150 (8 V)	72 V	150 Ah	10.80 kWh	8.64 kWh	313 kg
Scrubber, alternative	4 × 6-EVF-120 (12 V)	48 V	120 Ah	5.76 kWh	4.61 kWh	160 kg
AGV, alternative	2 × 6-EVF-120 (12 V)	24 V	120 Ah	2.88 kWh	2.30 kWh	80 kg

Individual model pages confirm the exact variant and terminal geometry for your tray: 4-EVF-150 8V150Ah specifications → and the full EVF electric road vehicle range →.

§2 — The Pain: Where Resort and Course Fleets Lose Money

The eight-hour shift that ends at eight hours. Most sightseeing vehicles in Thailand, Indonesia, the UAE, Italy and Mexico run 8–10 hours a day in high ambient temperatures, with stops, climbs and passenger loading throughout. A pack that reaches the end of its shift with 12% rather than 30% remaining means the operator charges every night regardless — and if the charge is missed once, the vehicle is out of service the next morning.

Ambient temperature is doing more damage than cycle count. The published cycle life of 350–600 cycles assumes 25°C. Above 35°C, float life and usable capacity both fall, and the pack’s terminal voltage sag under load becomes visible to operators as “the cart feels slow uphill”. Compounded by a charger with no temperature compensation, a tropical deployment can consume the upper cycle band in three years rather than five.

The unit-voltage choice and the service bay. A 48V pack built from 8V blocks contains four cells per unit. A 48V pack built from 12V blocks contains six. Both give the same bus voltage — the difference is entirely in how many units the technician handles, how many interconnects exist to corrode, and how many different spare part numbers the depot must stock. A resort operating two vehicle classes on the same 48V architecture can halve its spare part line by standardising on one unit voltage. That is a real and frequently ignored operating saving.

Weight and the passenger experience. A 209 kg battery in a 4–8 seat sightseeing vehicle consumes a meaningful share of the payload rating and of the vehicle’s stability. Where a resort operates hilly terrain with a full load, the choice between a 6-unit 8V pack and a 4-unit 12V pack is a handling decision before it is an electrical one.

§3 — The Choice: VRLA vs Flooded vs Lithium, Quantified

The table below models a realistic duty: a 30-cart golf course plus 10 sightseeing vehicles, 48V packs, 8 hours of daily operation, 6 days per week, 30°C average ambient, five-year horizon. All figures are a stated-assumption model so you can rebuild it with your own tariff, labour rate and duty profile — not a quotation.

Cost line (5 years, per 48V / 150Ah string)	Flooded lead-acid	AGM VRLA (6 × 4-EVF-150)	LFP 48V / 150Ah
Initial purchase	$1,180	$1,560	$2,480
Electricity over 5 years	$1,240	$1,080	$790
Watering and inspection labour	$1,340	$150	$70
Ventilation and cooling provision	$240	$110	$50
Replacement inside the 5-year window	$1,180	$0	$0
Battery-related downtime	$1,050	$340	$150
5-year total cost of ownership	$6,230	$3,240	$3,540

The $2,990 gap per string is labour and replacement. Flooded cells need a technician to walk the cart park, check levels, top with distilled water and manage corrosion — and in a resort or course operation that means scheduling around guest hours, which makes it expensive. AGM eliminates it. Across 40 vehicles the difference is $119,600 over five years.

Where the conclusion changes:

Flooded wins where carts are collected nightly into a workshop with a dedicated technician, and that technician’s time is already fully absorbed. The $1,340 labour line then collapses and the gap narrows to roughly $1,800 per string.
Lithium wins where payload matters more than capital: aerial platforms, marine craft, or steep-terrain fleets where every kilogram saved translates into more guests carried. It also removes the overnight charging window entirely if your charger can deliver the required energy in the available time.
Lithium is only $300 more expensive than VRLA over five years here, which is closer than the market usually assumes — and it is a rounding error across 40 vehicles. The gap between the two collapses further if your duty runs two full cycles a day rather than one.

The unit-count decision, quantified. All three options below deliver the same 48V bus voltage. They differ in mass, energy, spare-part complexity and — often overlooked — how many replacement units your depot must hold.

48V pack design	String capacity	Nominal energy	Pack weight	Units per pack	Spare coverage from one spare unit	Relative depot complexity
6 × 4-EVF-150 (8 V)	150 Ah	7.20 kWh	209 kg	6	17% of a fleet	Highest (6 part numbers)
4 × 6-EVF-120 (12 V)	120 Ah	5.76 kWh	160 kg	4	25%	Lowest (4 part numbers)
8 × 3-EVF-200 (6 V)	200 Ah	9.60 kWh	272 kg	8	12.5%	Highest (8 part numbers)

The decision rule that follows. If your duty is fixed-course, short-route and weight-insensitive — golf carts on a flat course — take the 6 × 4-EVF-150 and spend the difference on more energy per shift. If your duty is variable, payload-constrained and you want minimum depot complexity, take the 4 × 6-EVF-120 and accept 20% less energy. If you have steep terrain, long routes or a 10-hour operating day, the 8 × 3-EVF-200 gives the energy but you must budget for the 272 kg mass.

§4 — The Framework: Six Criteria Before You Issue a Purchase Order

1. Establish the discharge rate, then the real capacity. Not the motor rating — the measured current draw during the heaviest part of the duty: full passenger load, steepest gradient, simultaneous auxiliary loads. Multiply by the required operating hours, add 25–30% margin, and select at that rate. A 48V string of six 4-EVF-150 units delivers 7.20 kWh nominal and about 5.76 kWh usable at 80% depth of discharge.

2. Fix the unit voltage and the unit count in writing. Six 8V blocks give 48V; eight give 64V; nine give 72V. Write “48V, 6 × 4-EVF-150” into the order. Do not write “48V battery” — you will receive whatever the supplier considers standard, and the configuration difference between 6 units and 4 units is 49 kg of mass.

3. Match the charger to the cell, and turn on temperature compensation. Maximum charging current for the 4-EVF-150 is 30.0 A. The charger must be on the VRLA profile: 9.0 V float, 9.4 V equalise, 1.75 V per cell cutoff, with approximately −3 mV per °C per cell compensation. A flooded-profile charger will over-charge the pack; a charger without compensation will under-charge it in a 30–38°C bay — which is the single most common cause of early failure in resort operations.

4. Check the charging window against the operating window. A 48V string of six 4-EVF-150 units needs a genuine overnight charge to reach full capacity. Confirm the charger’s output current against the pack’s 30.0 A per unit limit, and confirm that the charge completes inside the window between the last evening run and the first morning run, including the temperature compensation effect that lengthens winter charging.

5. Write the date-code rule into the purchase order. All units in one pack should come from one production batch, no more than three months apart in date code. For a fleet of 40 vehicles this is worth more than any unit-price negotiation, because it removes the single largest cause of warranty disputes in traction packs.

6. Plan the commissioning and the first-season baseline. New or long-stored units need three full charge cycles of at least 10–12 hours each before entering service. Record per-unit open-circuit voltage, ambient temperature and vehicle number as the baseline. Without that record, month-18 diagnosis is guesswork, and guesswork becomes a warranty claim.

§5 — The Trust Layer: What to Demand, and What to Verify

What CHISEN puts behind the product. CHISEN has manufactured lead-acid batteries since 2002, with 8 production bases and 70 GWh of annual capacity across 2V, 6V, 8V and 12V from 4Ah to 3,000Ah, in the DZF, DMF, FD, EVF, GFM, OPzV and OPzS series plus lithium. Export documentation covers 60+ destination markets, with MSDS, land and sea transport report, certificate of origin and quality inspection report prepared for customs clearance. Technical support runs in Chinese, English, Japanese, Spanish, Arabic and Russian with a 12-hour email response target, and sample units ship on request. Company details: about CHISEN Battery →.

The seven failure modes, root cause and prevention.

Failure mode	Root cause	Prevention
Sulphation from chronic undercharge	Float below 8.8 V on an 8V unit, or no temperature compensation	Verify charger float at 9.0 V and compensation at −3 mV/°C/cell at the controller, not only at the battery
Premature capacity fade	Pack sized on the nameplate and operated at C3 with no margin	Size at the measured discharge rate; add 25–30% margin
Weak unit in a mixed-age pack	Units of different production dates in one string	Written date-code rule: same batch, maximum three months apart
Terminal corrosion and heating	Terminal torque below specification, loose interconnects	Torque every φ20-M8 terminal to specification at commissioning and re-torque annually
Thermal stress during charge	Charge in an enclosed, unventilated bay at high ambient	Charge outdoors or in a ventilated bay; never charge a pack above 45°C
Capacity loss from deep discharge	Repeated running below the 1.75 V per cell cutoff	Recharge at 20% remaining capacity; never leave a pack below 10% for more than 24 hours
Grid corrosion from deep discharge	Standing at low state of charge for long periods	Store at full charge, top up monthly, and re-check capacity before returning to service

Commissioning checklist — complete before the first load test.

Confirm every unit in the pack carries the same date code and batch, with no more than three months between units.
Measure and record open-circuit voltage for each unit. A spread wider than 0.05 V per cell across the pack needs an equalisation cycle before the pack goes into service.
Torque every φ20-M8 terminal to specification and photograph the reading for each pack. That photograph settles warranty arguments.
Verify the charger is on the VRLA profile: 9.0 V float, 9.4 V equalise, 1.75 V per cell cutoff, maximum 30.0 A, temperature compensation active.
Run three full charge cycles of at least 10–12 hours each on new or long-stored units so the cells reach full capacity.
Log the baseline: per-unit voltage, ambient temperature, and vehicle number.

One thing about temperature that buyers consistently underestimate. The −15°C to 50°C operating range covers discharge and general use, but do not charge below 0°C. Lead-acid chemistry cannot absorb charge efficiently at sub-zero temperatures, and charging a cold pack risks freezing the electrolyte inside the cell. In cold-climate operation, bring the pack to at least 5°C in a warm bay before charging and keep the batteries on float rather than switching them off for the winter.

§6 — FAQ: 9 Questions Fleet Buyers Ask Before Ordering

Q1. What does “4-EVF-150 8V150Ah” specify? An 8-volt sealed VRLA (AGM) deep-cycle battery with four 2V cells, rated at 150 amp-hours at the 3-hour rate, with a φ20-M8 terminal. The “4” is the cell count giving 8V, “EV” denotes the electric-vehicle category under GB/T 32620, “F” denotes the valve-regulated sealed construction, and “150” is the amp-hour rating at C3.

Q2. Is the 150Ah rating at C3 or C10? At C3. At the ten-hour rate the same cell delivers roughly 125–132Ah, a 12–17% reduction caused by the Peukert effect — the physical reality that lead-acid gives back less energy when you pull it harder. Size on your measured discharge rate and add 25–30% margin.

Q3. How many units do I need for a 48V system? Six units in series. Eight give 64V and nine give 72V, both with the same 150Ah string capacity because series wiring adds voltage and not amp-hours. A six-unit pack weighs 209 kg and delivers 7.20 kWh nominal, about 5.76 kWh usable at 80% depth of discharge.

Q4. Why would I use 12V units instead of 8V units in the same 48V pack? Four 12V units of 120Ah give the same bus voltage with 5.76 kWh and only 160 kg — 49 kg lighter, at 20% less energy and four part numbers instead of six. Choose 8V units when energy per shift is the binding constraint, and 12V units when payload and depot simplicity are.

Q5. Can I mix 4-EVF-150 units with other EVF models in one pack? Within one series string, use identical models with matched date codes. Different capacities in the same string create imbalance, and the weakest unit limits the whole string. If you need a different capacity, build parallel strings of matched units rather than mixing capacities inside a series string.

Q6. What charger do I need? One rated at a maximum of 30.0 A for this cell, configured for the VRLA profile: 9.0 V float, 9.4 V equalise, 1.75 V per cell cutoff, with approximately −3 mV per °C per cell temperature compensation. Confirm the charger completes a full charge inside your overnight window at the lowest expected ambient temperature, since compensation lengthens winter charging.

Q7. What is the realistic service life in a hot climate? The published figure is 350–600 cycles at 50–80% depth of discharge, or a 2–5 year design life. In a 30–38°C ambient with correct float voltage, temperature compensation and disciplined date-coded procurement, plan on the lower half of that range. Ambient temperature, not the calendar, decides how quickly those cycles arrive.

Q8. Can these batteries go by air, and what documents do I need? Yes. Sealed VRLA cells carry no free electrolyte and are considerably easier to ship than flooded batteries. The standard export pack includes MSDS, a land and sea transport report, and certificate of origin, with lead-acid batteries handled under the UN2794 dangerous-goods framework. Confirm requirements with your forwarder before booking.

Q9. Is the 4-EVF-150 suitable for solar storage or a telecom DC panel? Not as the primary choice. The EVF series is engineered for high-rate traction discharge, which is the opposite profile to a slow, deep stationary discharge. For telecom DC panels, data-centre UPS, railway signalling or solar storage, specify the stationary tubular families — OPzS flooded tubular for the longest float life, or OPzV sealed tubular gel where the site is unmanned.

Expert Summary

For fleet and OEM buyers evaluating the 4-EVF-150 8V150Ah, the decisive facts are these. It is an 8-volt, four-cell, fully sealed VRLA (AGM) deep-cycle battery rated at 150 amp-hours at the three-hour rate, built to GB/T 32620.1-2016 and GB/T 32620.2-2016 with reference to JB/T 2599, with a published footprint of 260 × 180 × 280 mm, a weight of 34.8 kg, a φ20-M8 terminal and a charging current of 30.0 A. Rated cycle life is 350–600 cycles at 50–80% depth of discharge with a 2–5 year design life across a −15°C to 50°C operating range; float is 9.0 V, equalise 9.4 V, cutoff 1.75 V per cell, and self-discharge is no more than 3% per month at 25°C. Six units in series form a 48V string of 150Ah delivering 7.20 kWh nominal and about 5.76 kWh usable at 80% depth of discharge, at a pack weight of 209 kg; eight units give 64V and nine give 72V, both still at 150Ah because series wiring adds voltage and not capacity. The decisive engineering point is that the 150Ah figure is a three-hour-rate rating — at C10 the same cell yields only about 125–132Ah — and that the choice of unit voltage is a three-way trade-off between energy per shift, payload and depot part complexity: six 8V blocks, four 12V blocks or eight 6V blocks all deliver the same 48V bus at 7.20, 5.76 or 9.60 kWh and 209, 160 or 272 kg. In a modelled 40-vehicle resort and golf-course fleet running 8-hour days at 30°C ambient, the five-year total cost of ownership per 48V string is approximately $3,240 for VRLA AGM against $6,230 for flooded lead-acid and $3,540 for LFP, the VRLA advantage coming almost entirely from eliminated watering labour and mid-life replacement rather than from unit price. Two installation faults cause most premature failures — chronic undercharge from a charger without temperature compensation and mixed production dates within a single pack — and both are eliminated by a written date-code rule and a correctly configured charger. CHISEN supplies the 4-EVF-150 factory-direct from 8 production bases with 70 GWh of annual capacity, CE / RoHS / REACH / MSDS / IMDG documentation prepared for 60+ destination markets, and free engineering sizing returned within 24 hours.

Contact CHISEN — 24-Hour Response

CHISEN Battery — 20+ years manufacturing lead-acid batteries, exporting to 60+ countries from 8 production bases with 70 GWh annual capacity.

Email: sales@chisen.cn — full quotation and sizing table within 24 hours
Phone / WhatsApp: +86 131 6622 6999
WhatsApp: https://wa.me/8613166226999
Model page: https://www.chisen.cn/en/4-EVF-150/8V150Ah.html

Send us pack voltage + units per pack + measured discharge current + daily operating hours + worst-case ambient temperature + destination country, and our engineering team returns a complete sizing sheet — cell count, capacity margin, charger profile, temperature derating and documentation scope — within one working day. Sample units are available on request for your own capacity test before you commit to a full bank.

Full product range and current production data: https://www.leadacidbattery.cn

Published by CHISEN Battery. Standard data per CHISEN 4-EVF-150 published datasheet, GB/T 32620.1-2016 and GB/T 32620.2-2016. TCO figures are a stated-assumption model for comparison, not a quotation. Availability, certification and destination-specific approvals confirmed on request.

October 22, 2026

6-EVF-60 12V60Ah AGM Battery: Sizing, Charger and 6-Year TCO

Reading time: 18 minutes | For: AGV and AMR fleet engineers, 3PL and contract logistics operators, light-equipment OEMs, golf-course and resort fleet managers, and battery distributors across North America, Europe, the Gulf and South-East Asia

Answer First

The 6-EVF-60 12V60Ah is a 12-volt, 60 amp-hour sealed AGM (VRLA) deep-cycle battery built for light electric vehicles and industrial equipment: AGVs and AMRs, light electric forklifts and pallet trucks, floor scrubbers and sweepers, small sightseeing vehicles, golf carts, and standby duties in security, monitoring and telecom applications. It is the highest-volume member of the EVF series, and it is also the one most often specified from memory rather than from a datasheet — which is where problems start.

Five numbers decide the procurement:

60Ah at the 3-hour rate (C3). At C10 the same cell delivers roughly 50–52Ah, a 13–17% gap. Most 12V 60Ah batteries on the market are rated at C20 or C10; this one is a 3-hour-rate cell, and the comparison is not like-for-like.
258 × 170 × 160 mm at 18.8 kg. Four units in series form a 48V pack weighing 75 kg and delivering 2.88 kWh nominal — roughly 2.3 kWh usable at 80% depth of discharge.
12.0 A charging current (0.2C) — this is the figure most often missed, and it is the number that decides which charger you can fit.
350–600 cycles at 50–80% depth of discharge, a 2–5 year design life, and a −15°C to 50°C operating range.
Float 13.5 V, equalise 14.1 V, cutoff 1.75 V per cell, self-discharge ≤ 3% per month at 25°C, and a one-way safety valve regulated between 10 and 49 kPa.

The honest caveat: at 60Ah the 6-EVF-60 sits at the bottom of the EVF range, and that creates a specific trap. The 6-EVF-100 and 6-EVF-120 share the same 12V architecture but carry 67% and 100% more energy, while remaining at the same four-unit pack count. If you size a 48V pack on four 6-EVF-60 units when the duty needs more, you will buy a second battery rather than a larger one, and end up with two packs, twice the terminals, twice the interconnects and twice the failure surface. §3 shows when the smaller cell is genuinely correct.

Key Takeaways

6-EVF-60 = 12V (6 cells), 60Ah at C3, 258 × 170 × 160 mm, 18.8 kg, φ14-M6 terminal, 12.0 A max charge current. Published figure.
Pack math: 2 units = 24V, 4 units = 48V, 6 units = 72V — string capacity stays at 60Ah, because series wiring adds voltage and not amp-hours.
The pack-count trap. Four 6-EVF-60 units in a 48V pack deliver 2.88 kWh. Four 6-EVF-120 units deliver 5.76 kWh with the same unit count, the same voltage and only 85 kg more. Always compare energy per pack, not amp-hours per cell.
Charger compatibility is not interchangeable across the EVF range. Maximum charge current runs from 12.0 A on the 6-EVF-60 to 40.0 A on the 3-EVF-200, and the float voltage follows the unit voltage — 13.5 V on 12V units, 9.0 V on 8V units, 6.75 V on 6V units.
For two-shift AGV duty, VRLA and lithium converge to within about 6% on 6-year TCO — $2,060 against $2,190 per 48V string. Past that point the choice is capital versus weight and cycle life, not cost.
CHISEN supplies factory-direct from 8 production bases with 70 GWh annual capacity, with CE / RoHS / REACH / MSDS / IMDG documentation prepared for 60+ destination markets, and technical support in six languages.

§1 — The Published Specification Table

Every figure below is taken from the CHISEN 6-EVF-60 published datasheet.

Parameter	Specification
Model	6-EVF-60
Nominal voltage	12 V (6 cells × 2 V)
Rated capacity	60 Ah at C3 (3-hour rate, 1.75 V/cell cutoff)
Dimensions (L × W × H)	258 × 170 × 160 mm
Total height with terminals	160 mm
Weight	18.8 kg ± 0.2 kg
Terminal configuration	φ14-M6
Charging current	12.0 A
Cycle life	350–600 cycles at 50–80% depth of discharge
Design life	2–5 years
Float charge voltage	13.5 V (2.25 V/cell)
Equalise charge voltage	14.1 V (2.35 V/cell)
Cutoff voltage	1.75 V per cell
Charge acceptance	≤ 4 hours to 80% state of charge
Self-discharge	≤ 3% per month at 25°C
Working temperature	−15°C to 50°C
Storage temperature	−20°C to 45°C
Safety valve	10–49 kPa automatic regulation
Case material	ABS engineering plastic, flame-retardant V0 grade
Vibration resistance	GB/T 32620.1 compliant (3g for 2 hours)
Battery type	Valve-regulated lead-acid (VRLA), AGM technology
Standards	GB/T 32620.1-2016, GB/T 32620.2-2016, JB/T 2599
Certifications	CE, RoHS, REACH, MSDS, IMDG (sea freight), cadmium-free and mercury-free
Applications	AGVs and AMRs, light forklifts and pallet trucks, floor scrubbers, sightseeing vehicles, golf carts, security and standby duties

What the model code tells you. The leading 6 is the cell count — six 2V cells in series give 12V. EV is the electric-vehicle category under GB/T 32620, for lead-acid batteries used as the main power source in electric road vehicles rather than for starting, stationary or traction-industrial duty. F denotes valve-regulated construction, with a one-way safety valve that opens between 10 and 49 kPa so internal pressure self-regulates without leaking. The trailing 60 is the amp-hour rating at the three-hour rate. Every one of those four elements changes what the cell does — and a quotation that omits the rate is not a comparable quotation.

The EVF ladder, for reference when you step up or down a size.

Model	Voltage	Rate	Capacity	Dimensions (mm)	Weight	Terminal	Max charge current
3-EVF-200	6 V	C3	200 Ah	260 × 180 × 270	34.0 kg	φ20-M8	40.0 A
4-EVF-150	8 V	C3	150 Ah	260 × 180 × 280	34.8 kg	φ20-M8	30.0 A
6-EVF-60	12 V	C3	60 Ah	258 × 170 × 160	18.8 kg	φ14-M6	12.0 A
6-EVF-70	12 V	C3	70 Ah	259 × 170 × 210	23.3 kg	φ16-M6	—
6-EVF-80	12 V	C3	80 Ah	259 × 170 × 218	25.7 kg	φ16-M6	—
6-EVF-100	12 V	C3	100 Ah	330 × 170 × 218	31.5 kg	φ20-M8	—
6-EVF-120	12 V	C3	120 Ah	407 × 170 × 240	40.0 kg	φ20-M8	24.0 A
6-EVF-135	12 V	C3	135 Ah	338 × 172 × 280	45.0 kg	φ20-M8	—
6-EVF-150	12 V	C3	150 Ah	483 × 170 × 240	48.5 kg	φ20-M8	—

Note that the 6-EVF-60 is physically the shortest cell in the 12V range at 160 mm, because it has less plate area. That short case is an advantage under a low floor deck and a disadvantage in a bay where the cable run is tight.

Pack configurations.

Configuration	Units in series	Nominal voltage	String capacity (C3)	Nominal energy	Usable energy at 80% DoD	Pack weight
Compact AGV	2 × 6-EVF-60 (12 V)	24 V	60 Ah	1.44 kWh	1.15 kWh	37.6 kg
Light forklift / scrubber	4 × 6-EVF-60 (12 V)	48 V	60 Ah	2.88 kWh	2.30 kWh	75.2 kg
Heavier duty	6 × 6-EVF-60 (12 V)	72 V	60 Ah	4.32 kWh	3.46 kWh	112.8 kg

Individual model pages confirm the exact variant and terminal geometry for your tray: 6-EVF-60 12V60Ah specifications → and the full EVF electric road vehicle range →.

§2 — The Pain: Why “12V 60Ah” Is the Most Misquoted Specification in the Category

Three different “12V 60Ah” batteries exist, and only one of them is this one. The category contains 12V 60Ah cells rated at C20, at C10 and at C3. A C20 60Ah cell and a C3 60Ah cell have the same nameplate and very different behaviour. On a bench test at the 3-hour rate, the C20 cell delivers roughly 48–50Ah while the C3 cell delivers 60Ah — the reverse of what most buyers assume, because the “60Ah” figure on a C20 cell is an optimistic extrapolation rather than a measured value. On an AGV doing two-shift duty, the difference between a C20 cell and a C3 cell is roughly 15–20% of usable energy per cycle, which is the difference between a fleet that finishes its shift and one that does not.

The charger is the most common cause of early failure, and it is usually the quickest thing to fix. The 6-EVF-60 accepts a maximum of 12.0 A. A 20 A or 30 A charger — which is what most generic traction chargers deliver — will push this cell beyond its rating, raise internal temperature and accelerate plate corrosion. The converse error is just as common: a 5 A charger on a duty cycle that needs 12 A will leave the pack permanently undercharged, and the fleet will slowly fail on sulphation with no obvious fault.

The “one battery, one fault” assumption. A 48V pack of four 6-EVF-60 units presents to the technician as one object, but it is four independent sealed cells in series with three interconnects. Series failure is what kills strings: one weak unit drags the whole string down on every deep discharge, and because VRLA cells are sealed there is no specific gravity reading to reveal which one. Measuring each unit individually is the only way.

§3 — The Choice: VRLA vs Flooded vs Lithium, Quantified

The table below models a realistic duty: 60 AGVs and 25 light forklifts in a third-party logistics operation, 48V packs, two shifts per day, 350 operating days per year, 22°C average ambient, six-year horizon. All figures are a stated-assumption model so you can rebuild it with your own tariff, labour rate and duty profile — not a quotation.

Cost line (6 years, per 48V / 60Ah string)	Flooded lead-acid	AGM VRLA (4 × 6-EVF-60)	LFP 48V / 60Ah
Initial purchase	$310	$430	$1,180
Electricity over 6 years	$1,020	$940	$700
Watering and inspection labour	$1,260	$180	$90
Ventilation and cooling provision	$180	$90	$40
Replacement inside the 6-year window	$930	$0	$0
Battery-related downtime	$1,140	$420	$180
6-year total cost of ownership	$4,840	$2,060	$2,190

Read the last two rows carefully — this is not the usual result. On a two-shift AGV duty, lithium finishes only $130 more expensive than VRLA over six years — a 6% difference — because the replacement cost that dominates the flooded case is eliminated for both. At this duty profile, VRLA’s remaining advantage is capital, and lithium’s remaining advantages are weight (roughly 40% lighter per kWh), cycle life and the absence of any thermal management.

Where the conclusion changes:

Flooded is the clear loser here, and not because of energy cost. Two-shift duty with no watering route is simply incompatible with flooded cells. Its $2,780 gap to VRLA is 90% labour and replacement.
VRLA is the better financial answer for capital-constrained fleets. It wins on purchase price, and it wins decisively if your duty is one shift rather than two, because the replacement line then favours VRLA’s lower-cost cells.
Lithium becomes the better answer when payload is the constraint. On an AGV carrying totes, returning 30 kg of battery mass to payload directly increases units carried per shift, which converts into a return on the battery investment rather than a cost on it.

Now the decision that actually matters: which cell goes in the pack. All three designs below give the same 48V bus voltage; the first two also give the same four-unit pack count.

48V pack design	String capacity	Nominal energy	Usable at 80% DoD	Pack weight	Units per pack	Spare coverage from one spare unit
4 × 6-EVF-60	60 Ah	2.88 kWh	2.30 kWh	75 kg	4	25%
4 × 6-EVF-120	120 Ah	5.76 kWh	4.61 kWh	160 kg	4	25%
6 × 4-EVF-150 (8 V)	150 Ah	7.20 kWh	5.76 kWh	209 kg	6	17%

The decision rule that follows. Choose the 6-EVF-60 when the duty is a single shift, the run time is short, the machine has a tight floor clearance, or payload is critical and the pack is small. Choose the 6-EVF-120 when the duty is two shifts or the vehicle must finish the day on one charge, and the cost of adding a second pack — a second tray, a second set of terminals, a third failure point, double the maintenance visits — is worse than the cost of a larger cell. Choose the 8V 4-EVF-150 when the energy requirement exceeds what four 12V units can deliver.

Charger compatibility across the EVF range. One more table worth keeping, because chargers are rarely shared between different unit voltages in a mixed fleet.

Model	Unit voltage	Max charge current	Suitable charger output	Float	Equalise	Cutoff
6-EVF-60	12 V	12.0 A	10–12 A	13.5 V	14.1 V	1.75 V/cell
6-EVF-120	12 V	24.0 A	20–24 A	13.5 V	14.1 V	1.75 V/cell
4-EVF-150	8 V	30.0 A	25–30 A	9.0 V	9.4 V	1.75 V/cell
3-EVF-200	6 V	40.0 A	32–40 A	6.75 V	7.05 V	1.75 V/cell

§4 — The Framework: Six Criteria Before You Issue a Purchase Order

1. Establish the discharge rate, then the real capacity. Measure the actual current draw at the worst point of the cycle — full load, ramp start, auxiliary loads running. Multiply by required run time, add 25–30% margin, and select at that rate. Do not size on “60Ah” and do not size on the motor rating.

2. Size the pack, not the cell. Two 6-EVF-60 units give 24V; four give 48V; six give 72V. Write “48V, 4 × 6-EVF-60” on the order. If your duty needs 5 kWh of usable energy in a 48V pack, four 6-EVF-60 units will not deliver it, and a second pack is not the answer — the larger cell is.

3. Match the charger to the cell. Maximum charge current for the 6-EVF-60 is 12.0 A. The charger must be on the VRLA profile — 13.5 V float, 14.1 V equalise, 1.75 V per cell cutoff — and must include temperature compensation of roughly −3 mV per °C per cell. Verify the charge completes inside the available window, because an AGV that cannot charge between shifts simply cannot run two shifts.

4. Write the date-code rule into the purchase order. All four units of a pack should come from one production batch, no more than three months apart in date code. For a fleet of 85 vehicles this removes the largest single cause of warranty disputes at no cost.

5. Plan per-unit measurement into the maintenance schedule. Because VRLA cells are sealed, there is no electrolyte check to perform. The substitute is a monthly open-circuit voltage reading per unit, with a spread wider than 0.05 V per cell triggering a replacement rather than an equalisation charge. Budget 20 minutes per vehicle per month; it is the only way to identify a weak cell before it takes the string down.

6. Verify the physical fit and the terminal geometry. 258 × 170 × 160 mm and 18.8 kg per unit, φ14-M6 terminal. Confirm tray dimensions, hold-down bracket positions, cable cross-section against 12 A charge and your peak discharge current, and clearance for ventilation. The 160 mm case height is genuinely short, which helps under a low deck — and can leave you short on cable bend radius if the tray is shallow.

§5 — The Trust Layer: What to Demand, and What to Verify

What CHISEN puts behind the product. CHISEN has manufactured lead-acid batteries since 2002, with 8 production bases and 70 GWh of annual capacity. Over 100,000 units of the mainstream 6-DZF / 6-DMF / 6-EVF series are held as ready stock for immediate shipment. Export documentation covers 60+ destination markets, with MSDS, transport report, certificate of origin and quality inspection report prepared for customs clearance, and technical support in six languages with a 12-hour email response target. Company details: about CHISEN Battery →.

The seven failure modes, root cause and prevention.

Failure mode	Root cause	Prevention
Sulphation from chronic undercharge	Float below 13.2 V on a 12V unit, or no temperature compensation	Verify charger float at 13.5 V and compensation at −3 mV/°C/cell at the controller, not only at the battery
Overcharge and heat	Charger output above the 12.0 A cell limit	Select a 10–12 A charger per 6-EVF-60 unit and confirm the series/parallel charger configuration
Premature capacity fade	Pack sized on the nameplate, or the wrong rate class quoted	Confirm the cell is rated at C3; size at the measured discharge rate with 25–30% margin
Weak unit in a mixed-age pack	Units of different production dates in one string	Written date-code rule: same batch, maximum three months apart
Terminal corrosion and heating	Terminal torque below specification, loose interconnects	Torque every φ14-M6 terminal to specification at commissioning and re-torque annually
Capacity loss from deep discharge	Repeated running below the 1.75 V per cell cutoff	Recharge at 20% remaining capacity; never leave a pack below 10% for more than 24 hours
Grid corrosion from deep discharge	Standing at low state of charge for long periods	Store at full charge, top up monthly, and re-check capacity before returning to service

Commissioning checklist — complete before the first load test.

Confirm every unit in the pack carries the same date code and batch, with no more than three months between units.
Measure and record open-circuit voltage for each unit. A spread wider than 0.05 V per cell across the pack needs an equalisation cycle before the pack goes into service.
Torque every φ14-M6 terminal to specification and photograph the reading for each pack. That photograph settles warranty arguments.
Verify the charger is on the VRLA profile: 13.5 V float, 14.1 V equalise, 1.75 V per cell cutoff, maximum 12.0 A, temperature compensation active.
Run three full charge cycles of at least 10–12 hours each on new or long-stored units so the cells reach full capacity.
Log the baseline: per-unit voltage, ambient temperature, and vehicle number.

One thing about temperature that buyers consistently underestimate. The −15°C to 50°C operating range covers discharge and general use, but do not charge below 0°C. Lead-acid chemistry cannot absorb charge efficiently at sub-zero temperatures, and charging a cold pack risks freezing the electrolyte inside the cell. In cold-climate operation, bring the pack to at least 5°C in a warm bay before charging and keep the batteries on float rather than switching them off for the winter.

§6 — FAQ: 9 Questions Fleet Buyers Ask Before Ordering

Q1. What does “6-EVF-60 12V60Ah” specify? A 12-volt sealed AGM (VRLA) deep-cycle battery with six 2V cells, rated at 60 amp-hours at the 3-hour rate, with a φ14-M6 terminal. The “6” is the cell count, “EV” denotes the electric-vehicle category under GB/T 32620, “F” denotes the valve-regulated sealed construction, and “60” is the amp-hour rating at C3.

Q2. Is the 60Ah rating at C3 or C20, and does the difference matter? At C3. Most 12V 60Ah batteries in the market are rated at C20 or C10, and the figures are not interchangeable: on a 3-hour discharge a C20-rated cell typically gives 48–50Ah while a C3-rated cell gives 60Ah. On two-shift duty that 15–20% gap in usable energy per cycle is the difference between finishing the shift and calling for a tow.

Q3. How many units do I need for a 48V system? Four units in series, giving a 48V string of 60Ah — 2.88 kWh nominal, about 2.30 kWh usable at 80% depth of discharge, and 75 kg. Two units give 24V and six give 72V, both still at 60Ah because series wiring adds voltage and not amp-hours.

Q4. Why would I use the 6-EVF-120 instead of the 6-EVF-60 in the same 48V pack? Four 6-EVF-120 units deliver 5.76 kWh against 2.88 kWh for the 6-EVF-60, for 85 kg more and the same four-unit pack count. If your duty is two shifts, or the vehicle must complete the day on one charge, the larger cell is almost always less costly than fitting a second pack — a second tray, a second set of terminals and double the maintenance visits.

Q5. What charger do I need? One rated at a maximum of 12.0 A for this cell, configured for the VRLA profile: 13.5 V float, 14.1 V equalise, 1.75 V per cell cutoff, with approximately −3 mV per °C per cell temperature compensation. A generic 20–30 A traction charger will over-drive this cell, and an under-sized charger will leave the pack permanently undercharged.

Q6. Can I mix 6-EVF-60 units with other EVF models in one pack? Within one series string, no. Use identical models with matched date codes; different capacities in the same string create imbalance and the weakest unit limits the whole string. If you need additional capacity, add a parallel string of matched units rather than mixing capacities inside a series string.

Q7. What is the realistic service life in a two-shift operation? The published figure is 350–600 cycles at 50–80% depth of discharge, or a 2–5 year design life. A two-shift AGV can reach 700 cycles a year, which means the cell is likely to be at the end of its useful life inside 18 months unless the duty is shallower than 80% depth of discharge. Plan a planned replacement rather than a failure replacement.

Q8. Can these batteries go by air, and what documents do I need? Yes. Sealed VRLA cells carry no free electrolyte and are considerably easier to ship than flooded batteries. The standard export pack includes MSDS, a land and sea transport report and certificate of origin, with lead-acid batteries handled under the UN2794 dangerous-goods framework. Confirm requirements with your forwarder before booking.

Q9. Is the 6-EVF-60 suitable for solar storage or a telecom DC panel? Not as the primary choice. The EVF series is engineered for high-rate traction discharge, the opposite profile to a slow, deep stationary discharge. For telecom DC panels, data-centre UPS, railway signalling or solar storage, specify the stationary tubular families — OPzS flooded tubular for the longest float life, or OPzV sealed tubular gel where the site is unmanned.

Expert Summary

For fleet and OEM buyers evaluating the 6-EVF-60 12V60Ah, the decisive facts are these. It is a 12-volt, six-cell, fully sealed AGM (VRLA) deep-cycle battery rated at 60 amp-hours at the three-hour rate, built to GB/T 32620.1-2016 and GB/T 32620.2-2016 with reference to JB/T 2599, with a published footprint of 258 × 170 × 160 mm, a weight of 18.8 kg, a φ14-M6 terminal and a maximum charging current of 12.0 A. Rated cycle life is 350–600 cycles at 50–80% depth of discharge with a 2–5 year design life across a −15°C to 50°C operating range; float is 13.5 V, equalise 14.1 V, cutoff 1.75 V per cell, self-discharge no more than 3% per month at 25°C, and the safety valve regulated between 10 and 49 kPa. Two units in series give 24V, four give 48V and six give 72V, all with a 60Ah string capacity because series wiring adds voltage and not amp-hours; a four-unit 48V pack weighs 75 kg and delivers 2.88 kWh nominal, about 2.30 kWh usable at 80% depth of discharge. The decisive engineering point is that the 60Ah figure is a three-hour-rate rating, and the category contains 12V 60Ah cells rated at C20, C10 and C3 that are not interchangeable; on a two-shift duty the difference is 15–20% of usable energy per cycle. In a modelled 85-vehicle third-party logistics fleet running two shifts at 22°C ambient, the six-year total cost of ownership per 48V string is approximately $2,060 for VRLA AGM against $4,840 for flooded lead-acid and $2,190 for LFP — a 6% gap between VRLA and lithium, which is the point at which the decision stops being about cost and becomes about capital, weight and cycle life. Charger selection is the most direct protection available: the 12.0 A cell limit, the 13.5 V VRLA float and the −3 mV per °C per cell compensation are all specified values, and deviating from any of them causes early failure. CHISEN supplies the 6-EVF-60 factory-direct from 8 production bases with 70 GWh of annual capacity, over 100,000 units of ready stock on the mainstream 6-DZF / 6-DMF / 6-EVF series, CE / RoHS / REACH / MSDS / IMDG documentation prepared for 60+ destination markets, and free engineering sizing returned within 24 hours.

Contact CHISEN — 24-Hour Response

CHISEN Battery — 20+ years manufacturing lead-acid batteries, exporting to 60+ countries from 8 production bases with 70 GWh annual capacity.

Email: sales@chisen.cn — full quotation and sizing table within 24 hours
Phone / WhatsApp: +86 131 6622 6999
WhatsApp: https://wa.me/8613166226999
Model page: https://www.chisen.cn/en/6-EVF-60/12V60Ah.html

Send us pack voltage + units per pack + measured discharge current + shifts per day + worst-case ambient temperature + destination country, and our engineering team returns a complete sizing sheet — cell count, capacity margin, charger profile, temperature derating and documentation scope — within one working day. Sample units are available on request for your own capacity test before you commit to a full bank.

Full product range and current production data: https://www.leadacidbattery.cn

Published by CHISEN Battery. Standard data per CHISEN 6-EVF-60 published datasheet, GB/T 32620.1-2016 and GB/T 32620.2-2016. TCO figures are a stated-assumption model for comparison, not a quotation. Availability, certification and destination-specific approvals confirmed on request.

Related CHISEN Buyer Guides

October 22, 2026

12v lead acid battery wholesale procurement guide 2026 6

OPzV2-700 2V 700Ah Tubular Gel Battery: Supplier Selection for Telecom

The OPzV2-700 2V 700Ah tubular gel battery is the middle of the range where most telecom and solar-hybrid banks actually land: large enough that a 48V string carries real autonomy, small enough that a technician can still replace a cell without a crane. A 24-cell string of these cells gives a 48V nominal bus with 33.6 kWh stored, floats at 54.0–54.5V, and carries a published float service life of 20+ years at 25°C with a cycle rating of at least 1,500 cycles at 80% depth of discharge. This guide covers how to verify those claims before you commit a container order.

[image placeholder: opzv2-700-2v-700ah-tubular-gel-battery-supplier-selection-telecom-2026.png]

Answer First

A 48V DC plant built from 24 OPzV2-700 cells in series stores 33.6 kWh nominal (24 × 2V × 700Ah), delivers 16.8 kWh at a 50% depth of discharge to 1.80V per cell, and floats at 54.0–54.5V with temperature compensation of −3.3mV per °C per cell. The cell measures 254 × 210 × 471mm with a 506mm total height, weighs 52.0kg filled, and uses a Φ20-M8 terminal tightened to 10–12 N·m — so a two-person lift and a standard 19-inch cabinet depth are the two physical constraints that decide whether this size is right for your site.

Key Takeaways

700Ah at C10, not nameplate Ah. The published rating is 700Ah on the 10-hour rate to 1.80V per cell at 25°C, which is the number to put on a purchase order. A cell quoted on a 20-hour rate delivers roughly 5–8% less at the 1-hour rate your rectifier actually imposes.
Float voltage 2.25–2.27V per cell at 25°C, compensated −3.3mV per °C per cell. On 24 cells that is 54.0–54.5V float and 55.2–56.4V equalising. Anything quoted without the compensation coefficient is not a comparable float life.
Cycle life is published by depth of discharge, not as one headline number. At least 1,500 cycles at 80% DoD, 2,500 at 50%, 4,000 at 30% and 5,500 at 20% at 25°C — the solar-hybrid case is usually the 30% row, not the 80% row.
Float service life of 20+ years applies at 25°C only. The widely used engineering rule of thumb is that float life roughly halves for every 10°C above 25°C, so a plant room at 35°C is a ten-year battery, not a twenty-year battery.
One model covers the whole 48V fleet. The tubular gel range runs from OPzV2-100 at 100Ah to OPzV2-3000 at 3000Ah in published dimension and weight tables, so a site fleet can be standardised on one platform with capacity steps rather than a mix of manufacturers.

Quick Specifications: The Published OPzV2-700 Data

Cell-level electrical and operating data for the 700Ah size, as published on the OPzV2-700 product page:

Parameter	Published value
Model	OPzV2-700
Technology	Tubular positive plate, nano gelled electrolyte, valve-regulated sealed VRLA
Nominal voltage	2V DC
Rated capacity	700Ah at C10 to 1.80V/cell, 25°C
Float / standby voltage	2.25–2.27V per cell at 25°C, compensation −3.3mV/°C/cell
Equalising voltage	2.30–2.35V per cell at 25°C, compensation −5mV/°C/cell
Cycling charge voltage	2.35–2.40V per cell at 25°C
Maximum charging current	140A (0.20 × C10)
Maximum discharge current (5s)	2,000A
Short-circuit current	3,300A
Internal resistance	0.55 mΩ fully charged at 25°C
Self-discharge	2% per month at 20–25°C; storable 12 months without recharging at 25°C
Cycle life	≥1,500 cycles at 80% DoD; 2,500 at 50%; 4,000 at 30%; 5,500 at 20%; 800 at 100%
Float service life	20+ years at 25°C
Discharge / charge / storage temperature	−40°C to +65°C / −30°C to +65°C / −25°C to +45°C
Dimensions	254 × 210 × 471mm (total height 506mm over terminals)
Weight	52.0kg filled with electrolyte
Terminal	Φ20-M8, 10–12 N·m (Φ16-M6 and Φ24-M10 options)
Standards	IEC 60896-21/22:2004, IEC 61427, DIN 40472:2015, GB/T 19638.1-2014, YD/T 1360, Eurobat Long Life, BS 6290 Part 4, UL 1989
Transport and environmental	IMDG Class 8, UN2794, MSDS, RoHS, REACH, WEEE

Capacity versus ambient temperature on the 10-hour rate, which is the correction most often skipped in a quotation:

Ambient	Capacity (% of rated)	Operating note
50°C	~107%	High-temperature limit, life materially reduced
40°C	~105%	Forced ventilation normally required
25°C	100%	Rating reference, 20+ year float design life
0°C	~80%	Slight capacity reduction
−20°C	~55%	Extreme cold, significant capacity loss

Where the 700Ah size sits in the published dimensional series, against its two closest neighbours on the OPzV tubular gel range page:

Model	Capacity C10 (Ah)	Length (mm)	Width (mm)	Height (mm)	Total height (mm)	Weight (kg)
OPzV2-600	600	145	206	646	681	44.20
OPzV2-700	700	254	210	471	506	52.00
OPzV2-800	800	191	210	646	681	60.00

The Pain: Where Telecom Battery Banks Fail Before They Age

Most battery banks that disappoint in year four were specified correctly on day one. They were then operated outside the envelope the datasheet describes, and the failure surfaces at the worst possible moment — during a grid outage in the middle of a monsoon in Karachi, a heatwave in Lagos, or a coastal salt fog event on a site near the Port of Santos.

Autonomy is stated in hours without a discharge rate. “Eight hours of backup” is meaningless unless the end voltage and the rate are fixed. A 700Ah cell returns close to 700Ah over ten hours, but noticeably less over three hours and considerably less over one. When the rectifier fails and the inverter carries a hard load, the usable energy is the rate-corrected figure, not the nameplate.

Float-current headroom is missing from the rectifier spec. At float the rectifier must carry the site load plus the battery’s own float current — roughly 1–2% of C10, so about 7–14A per 700Ah cell — plus whatever is needed to equalise a diverged string. A rectifier sized exactly to the site load will never recover a bank that has run undercharged for a week.

Temperature compensation is switched off. The published −3.3mV/°C/cell changes the float setpoint by roughly 0.2V across a 24-cell string between a 20°C and 40°C plant room. Without it, a hot climate over-charges daily, which consumes water in VRLA cells and shortens float life — precisely the opposite of the intended effect.

Cold sites are specified on a warm-site load profile. Capacity at −20°C is 55% of the 25°C rating. A cabinet outside Helsinki, Harare or Ulaanbaatar specified on a Dubai duty cycle will fail its autonomy test in January, even though the same bank passed every test in June.

There is no spare allowance. A single weak 2V cell can take a 48V string offline, because the bus voltage cannot be balanced around one cell. Buying two or three matched spares with the initial order costs less than one hour of site downtime.

The Choice: Chemistry, String Math and Total Cost

String and parallel arithmetic

Every cell in the OPzV range is 2V, so string length is fixed by the DC bus and only cell capacity and the number of parallel strings remain variable.

DC bus	Cells in series	Float voltage	Equalising voltage	Energy per 700Ah string	Energy per 2-string bank
24V	12	27.0–27.2V	27.6–28.2V	16.8 kWh	33.6 kWh
48V	24	54.0–54.5V	55.2–56.4V	33.6 kWh	67.2 kWh
80V	40	90.0–90.8V	92.0–94.0V	56.0 kWh	112.0 kWh
120V	60	135.0–136.2V	138.0–141.0V	84.0 kWh	168.0 kWh

A worked 48V telecom case

A rural mobile site near Lagos, a trackside cabinet outside Warsaw and a hybrid tower near the Port of Colombo share a common profile: a 1,200W continuous load, a 48V rectified bus, a 12-hour autonomy target and 30–35°C ambient.

Nominal energy: 24 cells × 700Ah = 33.6 kWh per string.
Deliverable at 50% DoD (1.80V/cell): 16.8 kWh → 14 hours at 1,200W.
Corrected for a 40°C plant room: ×1.05 → 17.6 kWh → 14.7 hours, provided the inverter’s DC undervoltage cutoff is set at or above 48.0V.
Rectifier sizing: 1,200W site load + 14A float current (2% of C10) + equalising reserve of roughly 140A at 2.35V ≈ 330W, so about 1.6kW continuous; a 2kW rectifier holds margin without exceeding the 140A per-cell maximum charging current.
Short-circuit check: 24 cells × 0.55 mΩ = 13.2 mΩ for the string, which by calculation gives roughly 4,100A. The published 3,300A figure governs, and the DC fuse rating should be set against it.

Chemistry comparison at 48V, 1,200W load, 12-hour autonomy

Cost and performance item (7-year horizon)	Tubular gel OPzV2-700	Flat-plate AGM 12V 700Ah block	LFP 48V 25kWh module
Initial purchase (24-cell / 4-block / 1-rack basis)	$4,560	$1,920	$9,500
7-year electricity at ~$0.18/kWh	$2,760	$2,500	$1,640
7-year cabinet cooling and ventilation	$320	$560	$1,180
7-year inspection and service labour	$0	$280	$1,120
Mid-life replacement inside 7 years	$0	$2,270 (one set plus labour)	$1,500 (capacity augmentation)
Downtime exposure	$600	$1,100	$480
7-year total	$8,240	$8,630	$15,420
Cost per delivered kWh (36,792 kWh over 7 years)	$0.224	$0.235	$0.419
Published cycle rating	1,500 cycles at 80% DoD	400–800 cycles at 80% DoD	3,000–5,000 cycles at 80% DoD
Watering and cell servicing	None (VRLA sealed)	None (VRLA sealed)	None, but BMS and HVAC service
Failure modes seen in the field	Grid corrosion and shedding on flat-plate designs	Premature capacity loss in sustained heat	Cell imbalance, BMS firmware, thermal management

Read this honestly: the flat-plate AGM option starts roughly 30% cheaper on capital cost, and in a cool 25°C float-only service with a guaranteed five-year replacement budget the gap can stay that way. The case for tubular gel is not the invoice — it is the absence of a mid-life replacement event, the removal of service labour, and the way the gap widens once the plant room sits above 30°C for most of the year. LFP wins decisively on cycle life and round-trip efficiency but costs roughly 87% more over seven years once HVAC, augmentation and maintenance are counted, which is why it remains a hybrid-site and generator-start alternative rather than the default for a 48V telecom cabinet.

The Framework: Seven Numbers to Put in the Purchase Specification

1. Capacity basis. Specify 700Ah at C10 to 1.80V per cell at 25°C, and ask the supplier to confirm the discharge curve used to certify it. A 700Ah cell quoted only on C20 is not the same cell in your application.

2. Float setpoint and compensation. 2.25–2.27V per cell at 25°C with −3.3mV/°C/cell, giving 54.0–54.5V across 24 cells. Write the compensation coefficient into the rectifier configuration sheet, not just the battery datasheet.

3. Cycle rating at your real depth of discharge. The published ladder — 1,500 cycles at 80%, 2,500 at 50%, 4,000 at 30%, 5,500 at 20% — lets you pick the row that matches the site’s energy profile instead of accepting the headline figure.

4. Temperature derating curve. 105% at 40°C, 80% at 0°C, 55% at −20°C. A supplier who publishes only the 25°C capacity is asking you to guess the rest.

5. Float life definition. “20+ years” is only meaningful alongside 25°C, 2.25–2.27V per cell and the compensation coefficient. Vendors quoting ten, twelve and fifteen years are usually using different float voltages or ambient assumptions; normalise all quotes to the same three conditions before comparing.

6. Standards and certification set. For EU, UK and North American utility and telecom procurement: IEC 60896-21/22:2004 for test methods and dimensions, DIN 40472:2015 for tubular VRLA, IEC 61427 for PV storage, BS 6290 Part 4 and UL 1989 for UK and US acceptance, plus Eurobat Long Life classification above twelve years float.

7. Serviceability and logistics. 254 × 210 × 471mm at 52.0kg with a 506mm total height determines cabinet choice and whether two people can handle a cell. Terminal type Φ20-M8 at 10–12 N·m sets the tooling on site. For freight, IMDG Class 8 and UN2794 apply, and at 52kg per cell a 20-foot dry container holds roughly 460 cells before pallet and dunnage weight is counted — which is close to the payload limit, so bank size is a freight-planning decision, not only an electrical one.

The Trust: How to Audit a Tubular Gel Supplier Before You Pay

The gap between a data sheet and a delivered cell is where procurement losses hide. These are the checks that separate a manufacturer from a trading company.

Ask for the capacity test, not the brochure. A logged 10-hour discharge curve at 0.1C with the voltage at the end of discharge, taken from a cell in the shipment you received, is the only evidence that matters. Many suppliers publish a datasheet copied from a cell they do not build.

Check whose cells are in the box. A manufacturer will state the plant, the annual output and the audit certificates without hesitation. A trading intermediary cannot. Ask which factory produced the lot and for the plant’s monthly output — for context, CHISEN operates eight production bases with an annual capacity of 70 million kVAh and holds ISO 9001, ISO 14001, CE and UL approvals across the range.

Compare float life on identical conditions. Reject every quote that does not state the ambient temperature, the float voltage per cell and the temperature compensation coefficient next to the years figure.

Verify the physical envelope, not just the weight class. Terminal type, torque figure, total height over terminals and the approved mounting orientation determine whether the cell fits the cabinet and whether the string can be installed horizontally or on its side in a confined outdoor enclosure — the OPzV range is published for vertical, horizontal and side installation, which matters in the tight outdoor cabinets common to 5G sites in Europe and Southeast Asia.

Run the supplier audit as a checklist, not a question. Before issuing a purchase order, confirm the datasheet, the IEC and DIN test reports, the Eurobat classification, the warranty terms with defined float-life conditions, the spare-cell policy, the delivery lead time, the packing data for IMDG carriage and the after-sales contact who will answer in twelve months.

Watch the lead-time story. Stationary VRLA is not capacity-constrained the way traction cells are in peak season, but a quoted 90-day lead time with no plant reference usually means the supplier is waiting for someone else’s production slot.

FAQ

1. What is the OPzV2-700 2V 700Ah tubular gel battery used for? It is a 2V stationary cell for telecom base stations and outdoor cabinets, solar and wind hybrid storage, medium UPS and industrial DC panels. Tubular positive plates and immobilised gel electrolyte make it a float-first, maintenance-free product, and the published 20+ year float life at 25°C suits sites with a permanent 48V or 240V DC bus.

2. How many OPzV2-700 cells do I need for a 48V telecom DC plant? Twenty-four cells in series. That gives a 48V nominal bus, 54.0–54.5V float and 55.2–56.4V equalising, with 33.6 kWh nominal per string. A second identical string in parallel doubles the capacity without changing the bus voltage.

3. What is the usable capacity of the OPzV2-700 in practice? 700Ah at the 10-hour rate to 1.80V per cell at 25°C. At a 50% depth of discharge a string delivers 16.8 kWh usable, which is 14 hours at a 1,200W continuous load. Multiply by 1.05 for a 40°C plant room and by 0.80 for a 0°C site.

4. How does it compare with a flat-plate AGM battery of the same capacity? Tubular plates resist shedding and grid corrosion in deep discharge, giving at least 1,500 cycles at 80% DoD against 400–800 for conventional AGM. On capital cost alone the AGM option is cheaper, but it needs one replacement inside a seven-year horizon at ambient temperatures above 30°C, and the 7-year model above puts the two within 5% of each other, with tubular gel ahead on risk and service labour.

5. Can OPzV2-700 cells be installed horizontally or inside a confined cabinet? Yes. The published range supports vertical, horizontal and side installation, which suits the constrained outdoor enclosures used for 5G and remote radio cabinets. Confirm the 506mm total height over terminals and the 52.0kg cell weight against your enclosure and handling plan.

6. What float voltage and compensation should I configure? 2.25–2.27V per cell at 25°C with −3.3mV per °C per cell compensation, which equals 54.0–54.5V across 24 cells at 25°C. Equalising is 2.30–2.35V per cell and cycling charge is 2.35–2.40V per cell. Program the compensation into the rectifier, not the manual.

7. What maintenance does a tubular gel battery need? No watering and no routine cell servicing, but four checks a quarter: string voltage at float against the 54.0–54.5V window, terminal torque at 10–12 N·m, cell casing and terminal condition for corrosion, and the temperature-compensation setting against the measured plant-room temperature. Record every reading — a drifting string is visible in the log months before it fails.

8. How long will the battery last in a hot plant room? The published 20+ years is a 25°C figure. The standard engineering rule is that float life roughly halves for every 10°C above 25°C, so expect roughly ten years at 35°C and nearer seven to eight years at 40°C if the float voltage is not compensated. This is why compensation is the single most valuable setting on the rectifier.

9. Is the OPzV2-700 suitable for solar hybrid sites that cycle daily? Yes, and this is where the published cycle ladder matters. At 30% depth of discharge the cell is rated for 4,000 cycles, which is roughly ten years of daily cycling at that profile. Continuous float life and deep-cycle capability are separate claims, so ask a supplier for the figure at your specific depth of discharge rather than the headline 80% number.

10. What certifications do I need for import into the EU and North America? For Europe, CE marking with IEC 60896-21/22:2004 and DIN 40472:2015 test reports, plus IEC 61427 where the site is a PV installation. For the United Kingdom, BS 6290 Part 4. For the United States, UL 1989. In all cases request the RoHS, REACH and WEEE declarations and the MSDS, and plan carriage under IMDG Class 8, UN2794.

11. Can I mix OPzV2-700 cells with other capacities in the same bank? Not inside a series string — every cell in a string must be the same model and, ideally, the same production batch and age. Different capacities can only be added as separate parallel strings with their own cable sizing, and mixing ages in parallel strings leads to current sharing problems because the newer cells carry more of the load.

12. What should I request from the supplier before placing the order? The full datasheet with the capacity test basis, the IEC and DIN test reports, the Eurobat classification, the warranty conditions stating float life assumptions, two to three spare cells at 2–3% of the order, packing and IMDG data, a stated lead time tied to a plant, and a named technical contact for commissioning support.

Expert Summary

The OPzV2-700 is a 2V, 700Ah tubular gel VRLA cell with a published 10-hour-rate capacity of 700Ah to 1.80V per cell, float service life of more than 20 years at 25°C, a cycle rating of at least 1,500 cycles at 80% depth of discharge and 4,000 cycles at 30%, dimensions of 254 × 210 × 471mm, a total height of 506mm, a filled weight of 52.0kg and a Φ20-M8 terminal at 10–12 N·m. Twenty-four cells in series form a 48V DC plant storing 33.6 kWh nominal and delivering 16.8 kWh at a 50% depth of discharge, floating at 54.0–54.5V with −3.3mV per °C per cell compensation. Tubular gel outperforms flat-plate AGM on cycle life and mid-life replacement exposure, at a capital cost roughly 30–40% higher than AGM and well below LFP on a seven-year total-cost basis. Float life must be read at the site temperature, not at 25°C, because life roughly halves for every 10°C of ambient increase.

Request a Quotation

Specify the model, the string configuration and the delivery port, and we will return a quotation with the datasheet, test certificates and shipping calculation.

Request a quotation: sales@chisen.cn
Technical and project discussion: jack@chisen.cn
WhatsApp: +86 131 6622 6999
Full specifications for this model: OPzV2-700 2V 700Ah product page
The complete tubular gel range: OPzV series overview
Need a supplier audit checklist or the cell datasheet pack? Ask for the audit checklist, IEC 60896 and DIN 40472 test reports, Eurobat classification and the full OPzV dimensional series with your enquiry.

For leadacidbattery.cn, browse the OPzV2-700 2V 700Ah tubular gel battery product page or contact us for a tailored quotation for your project.

Related CHISEN Buyer Guides

October 22, 2026

OPzV2-700 2V 700Ah Tubular Gel Battery: Supplier Selection for Telecom

[image placeholder: opzv2-700-2v-700ah-tubular-gel-battery-supplier-selection-telecom-2026.png]

Answer First

Key Takeaways

700Ah at C10, not nameplate Ah. The published rating is 700Ah on the 10-hour rate to 1.80V per cell at 25°C, which is the number to put on a purchase order. A cell quoted on a 20-hour rate delivers roughly 5–8% less at the 1-hour rate your rectifier actually imposes.
Float voltage 2.25–2.27V per cell at 25°C, compensated −3.3mV per °C per cell. On 24 cells that is 54.0–54.5V float and 55.2–56.4V equalising. Anything quoted without the compensation coefficient is not a comparable float life.
Cycle life is published by depth of discharge, not as one headline number. At least 1,500 cycles at 80% DoD, 2,500 at 50%, 4,000 at 30% and 5,500 at 20% at 25°C — the solar-hybrid case is usually the 30% row, not the 80% row.
Float service life of 20+ years applies at 25°C only. The widely used engineering rule of thumb is that float life roughly halves for every 10°C above 25°C, so a plant room at 35°C is a ten-year battery, not a twenty-year battery.
One model covers the whole 48V fleet. The tubular gel range runs from OPzV2-100 at 100Ah to OPzV2-3000 at 3000Ah in published dimension and weight tables, so a site fleet can be standardised on one platform with capacity steps rather than a mix of manufacturers.

Quick Specifications: The Published OPzV2-700 Data

Cell-level electrical and operating data for the 700Ah size, as published on the OPzV2-700 product page:

Parameter	Published value
Model	OPzV2-700
Technology	Tubular positive plate, nano gelled electrolyte, valve-regulated sealed VRLA
Nominal voltage	2V DC
Rated capacity	700Ah at C10 to 1.80V/cell, 25°C
Float / standby voltage	2.25–2.27V per cell at 25°C, compensation −3.3mV/°C/cell
Equalising voltage	2.30–2.35V per cell at 25°C, compensation −5mV/°C/cell
Cycling charge voltage	2.35–2.40V per cell at 25°C
Maximum charging current	140A (0.20 × C10)
Maximum discharge current (5s)	2,000A
Short-circuit current	3,300A
Internal resistance	0.55 mΩ fully charged at 25°C
Self-discharge	2% per month at 20–25°C; storable 12 months without recharging at 25°C
Cycle life	≥1,500 cycles at 80% DoD; 2,500 at 50%; 4,000 at 30%; 5,500 at 20%; 800 at 100%
Float service life	20+ years at 25°C
Discharge / charge / storage temperature	−40°C to +65°C / −30°C to +65°C / −25°C to +45°C
Dimensions	254 × 210 × 471mm (total height 506mm over terminals)
Weight	52.0kg filled with electrolyte
Terminal	Φ20-M8, 10–12 N·m (Φ16-M6 and Φ24-M10 options)
Standards	IEC 60896-21/22:2004, IEC 61427, DIN 40472:2015, GB/T 19638.1-2014, YD/T 1360, Eurobat Long Life, BS 6290 Part 4, UL 1989
Transport and environmental	IMDG Class 8, UN2794, MSDS, RoHS, REACH, WEEE

Capacity versus ambient temperature on the 10-hour rate, which is the correction most often skipped in a quotation:

Ambient	Capacity (% of rated)	Operating note
50°C	~107%	High-temperature limit, life materially reduced
40°C	~105%	Forced ventilation normally required
25°C	100%	Rating reference, 20+ year float design life
0°C	~80%	Slight capacity reduction
−20°C	~55%	Extreme cold, significant capacity loss

Where the 700Ah size sits in the published dimensional series, against its two closest neighbours on the OPzV tubular gel range page:

Model	Capacity C10 (Ah)	Length (mm)	Width (mm)	Height (mm)	Total height (mm)	Weight (kg)
OPzV2-600	600	145	206	646	681	44.20
OPzV2-700	700	254	210	471	506	52.00
OPzV2-800	800	191	210	646	681	60.00

The Pain: Where Telecom Battery Banks Fail Before They Age

The Choice: Chemistry, String Math and Total Cost

String and parallel arithmetic

Every cell in the OPzV range is 2V, so string length is fixed by the DC bus and only cell capacity and the number of parallel strings remain variable.

DC bus	Cells in series	Float voltage	Equalising voltage	Energy per 700Ah string	Energy per 2-string bank
24V	12	27.0–27.2V	27.6–28.2V	16.8 kWh	33.6 kWh
48V	24	54.0–54.5V	55.2–56.4V	33.6 kWh	67.2 kWh
80V	40	90.0–90.8V	92.0–94.0V	56.0 kWh	112.0 kWh
120V	60	135.0–136.2V	138.0–141.0V	84.0 kWh	168.0 kWh

A worked 48V telecom case

Nominal energy: 24 cells × 700Ah = 33.6 kWh per string.
Deliverable at 50% DoD (1.80V/cell): 16.8 kWh → 14 hours at 1,200W.
Corrected for a 40°C plant room: ×1.05 → 17.6 kWh → 14.7 hours, provided the inverter’s DC undervoltage cutoff is set at or above 48.0V.
Rectifier sizing: 1,200W site load + 14A float current (2% of C10) + equalising reserve of roughly 140A at 2.35V ≈ 330W, so about 1.6kW continuous; a 2kW rectifier holds margin without exceeding the 140A per-cell maximum charging current.
Short-circuit check: 24 cells × 0.55 mΩ = 13.2 mΩ for the string, which by calculation gives roughly 4,100A. The published 3,300A figure governs, and the DC fuse rating should be set against it.

Chemistry comparison at 48V, 1,200W load, 12-hour autonomy

Cost and performance item (7-year horizon)	Tubular gel OPzV2-700	Flat-plate AGM 12V 700Ah block	LFP 48V 25kWh module
Initial purchase (24-cell / 4-block / 1-rack basis)	$4,560	$1,920	$9,500
7-year electricity at ~$0.18/kWh	$2,760	$2,500	$1,640
7-year cabinet cooling and ventilation	$320	$560	$1,180
7-year inspection and service labour	$0	$280	$1,120
Mid-life replacement inside 7 years	$0	$2,270 (one set plus labour)	$1,500 (capacity augmentation)
Downtime exposure	$600	$1,100	$480
7-year total	$8,240	$8,630	$15,420
Cost per delivered kWh (36,792 kWh over 7 years)	$0.224	$0.235	$0.419
Published cycle rating	1,500 cycles at 80% DoD	400–800 cycles at 80% DoD	3,000–5,000 cycles at 80% DoD
Watering and cell servicing	None (VRLA sealed)	None (VRLA sealed)	None, but BMS and HVAC service
Failure modes seen in the field	Grid corrosion and shedding on flat-plate designs	Premature capacity loss in sustained heat	Cell imbalance, BMS firmware, thermal management

The Framework: Seven Numbers to Put in the Purchase Specification

4. Temperature derating curve. 105% at 40°C, 80% at 0°C, 55% at −20°C. A supplier who publishes only the 25°C capacity is asking you to guess the rest.

The Trust: How to Audit a Tubular Gel Supplier Before You Pay

The gap between a data sheet and a delivered cell is where procurement losses hide. These are the checks that separate a manufacturer from a trading company.

FAQ

Expert Summary

Request a Quotation

Specify the model, the string configuration and the delivery port, and we will return a quotation with the datasheet, test certificates and shipping calculation.

Request a quotation: sales@chisen.cn
Technical and project discussion: jack@chisen.cn
WhatsApp: +86 131 6622 6999
Full specifications for this model: OPzV2-700 2V 700Ah product page
The complete tubular gel range: OPzV series overview
Need a supplier audit checklist or the cell datasheet pack? Ask for the audit checklist, IEC 60896 and DIN 40472 test reports, Eurobat classification and the full OPzV dimensional series with your enquiry.

For leadacidbattery.cn, browse the OPzV2-700 2V 700Ah tubular gel battery product page or contact us for a tailored quotation for your project.

Related CHISEN Buyer Guides

October 22, 2026

OPzV2-700 2V 700Ah Tubular Gel Battery: Supplier Selection for Telecom

[image placeholder: opzv2-700-2v-700ah-tubular-gel-battery-supplier-selection-telecom-2026.png]

Answer First

Key Takeaways

700Ah at C10, not nameplate Ah. The published rating is 700Ah on the 10-hour rate to 1.80V per cell at 25°C, which is the number to put on a purchase order. A cell quoted on a 20-hour rate delivers roughly 5–8% less at the 1-hour rate your rectifier actually imposes.
Float voltage 2.25–2.27V per cell at 25°C, compensated −3.3mV per °C per cell. On 24 cells that is 54.0–54.5V float and 55.2–56.4V equalising. Anything quoted without the compensation coefficient is not a comparable float life.
Cycle life is published by depth of discharge, not as one headline number. At least 1,500 cycles at 80% DoD, 2,500 at 50%, 4,000 at 30% and 5,500 at 20% at 25°C — the solar-hybrid case is usually the 30% row, not the 80% row.
Float service life of 20+ years applies at 25°C only. The widely used engineering rule of thumb is that float life roughly halves for every 10°C above 25°C, so a plant room at 35°C is a ten-year battery, not a twenty-year battery.
One model covers the whole 48V fleet. The tubular gel range runs from OPzV2-100 at 100Ah to OPzV2-3000 at 3000Ah in published dimension and weight tables, so a site fleet can be standardised on one platform with capacity steps rather than a mix of manufacturers.

Quick Specifications: The Published OPzV2-700 Data

Cell-level electrical and operating data for the 700Ah size, as published on the OPzV2-700 product page:

Parameter	Published value
Model	OPzV2-700
Technology	Tubular positive plate, nano gelled electrolyte, valve-regulated sealed VRLA
Nominal voltage	2V DC
Rated capacity	700Ah at C10 to 1.80V/cell, 25°C
Float / standby voltage	2.25–2.27V per cell at 25°C, compensation −3.3mV/°C/cell
Equalising voltage	2.30–2.35V per cell at 25°C, compensation −5mV/°C/cell
Cycling charge voltage	2.35–2.40V per cell at 25°C
Maximum charging current	140A (0.20 × C10)
Maximum discharge current (5s)	2,000A
Short-circuit current	3,300A
Internal resistance	0.55 mΩ fully charged at 25°C
Self-discharge	2% per month at 20–25°C; storable 12 months without recharging at 25°C
Cycle life	≥1,500 cycles at 80% DoD; 2,500 at 50%; 4,000 at 30%; 5,500 at 20%; 800 at 100%
Float service life	20+ years at 25°C
Discharge / charge / storage temperature	−40°C to +65°C / −30°C to +65°C / −25°C to +45°C
Dimensions	254 × 210 × 471mm (total height 506mm over terminals)
Weight	52.0kg filled with electrolyte
Terminal	Φ20-M8, 10–12 N·m (Φ16-M6 and Φ24-M10 options)
Standards	IEC 60896-21/22:2004, IEC 61427, DIN 40472:2015, GB/T 19638.1-2014, YD/T 1360, Eurobat Long Life, BS 6290 Part 4, UL 1989
Transport and environmental	IMDG Class 8, UN2794, MSDS, RoHS, REACH, WEEE

Capacity versus ambient temperature on the 10-hour rate, which is the correction most often skipped in a quotation:

Ambient	Capacity (% of rated)	Operating note
50°C	~107%	High-temperature limit, life materially reduced
40°C	~105%	Forced ventilation normally required
25°C	100%	Rating reference, 20+ year float design life
0°C	~80%	Slight capacity reduction
−20°C	~55%	Extreme cold, significant capacity loss

Where the 700Ah size sits in the published dimensional series, against its two closest neighbours on the OPzV tubular gel range page:

Model	Capacity C10 (Ah)	Length (mm)	Width (mm)	Height (mm)	Total height (mm)	Weight (kg)
OPzV2-600	600	145	206	646	681	44.20
OPzV2-700	700	254	210	471	506	52.00
OPzV2-800	800	191	210	646	681	60.00

The Pain: Where Telecom Battery Banks Fail Before They Age

The Choice: Chemistry, String Math and Total Cost

String and parallel arithmetic

Every cell in the OPzV range is 2V, so string length is fixed by the DC bus and only cell capacity and the number of parallel strings remain variable.

DC bus	Cells in series	Float voltage	Equalising voltage	Energy per 700Ah string	Energy per 2-string bank
24V	12	27.0–27.2V	27.6–28.2V	16.8 kWh	33.6 kWh
48V	24	54.0–54.5V	55.2–56.4V	33.6 kWh	67.2 kWh
80V	40	90.0–90.8V	92.0–94.0V	56.0 kWh	112.0 kWh
120V	60	135.0–136.2V	138.0–141.0V	84.0 kWh	168.0 kWh

A worked 48V telecom case

Nominal energy: 24 cells × 700Ah = 33.6 kWh per string.
Deliverable at 50% DoD (1.80V/cell): 16.8 kWh → 14 hours at 1,200W.
Corrected for a 40°C plant room: ×1.05 → 17.6 kWh → 14.7 hours, provided the inverter’s DC undervoltage cutoff is set at or above 48.0V.
Rectifier sizing: 1,200W site load + 14A float current (2% of C10) + equalising reserve of roughly 140A at 2.35V ≈ 330W, so about 1.6kW continuous; a 2kW rectifier holds margin without exceeding the 140A per-cell maximum charging current.
Short-circuit check: 24 cells × 0.55 mΩ = 13.2 mΩ for the string, which by calculation gives roughly 4,100A. The published 3,300A figure governs, and the DC fuse rating should be set against it.

Chemistry comparison at 48V, 1,200W load, 12-hour autonomy

Cost and performance item (7-year horizon)	Tubular gel OPzV2-700	Flat-plate AGM 12V 700Ah block	LFP 48V 25kWh module
Initial purchase (24-cell / 4-block / 1-rack basis)	$4,560	$1,920	$9,500
7-year electricity at ~$0.18/kWh	$2,760	$2,500	$1,640
7-year cabinet cooling and ventilation	$320	$560	$1,180
7-year inspection and service labour	$0	$280	$1,120
Mid-life replacement inside 7 years	$0	$2,270 (one set plus labour)	$1,500 (capacity augmentation)
Downtime exposure	$600	$1,100	$480
7-year total	$8,240	$8,630	$15,420
Cost per delivered kWh (36,792 kWh over 7 years)	$0.224	$0.235	$0.419
Published cycle rating	1,500 cycles at 80% DoD	400–800 cycles at 80% DoD	3,000–5,000 cycles at 80% DoD
Watering and cell servicing	None (VRLA sealed)	None (VRLA sealed)	None, but BMS and HVAC service
Failure modes seen in the field	Grid corrosion and shedding on flat-plate designs	Premature capacity loss in sustained heat	Cell imbalance, BMS firmware, thermal management

The Framework: Seven Numbers to Put in the Purchase Specification

4. Temperature derating curve. 105% at 40°C, 80% at 0°C, 55% at −20°C. A supplier who publishes only the 25°C capacity is asking you to guess the rest.

The Trust: How to Audit a Tubular Gel Supplier Before You Pay

The gap between a data sheet and a delivered cell is where procurement losses hide. These are the checks that separate a manufacturer from a trading company.

FAQ

Expert Summary

Request a Quotation

Specify the model, the string configuration and the delivery port, and we will return a quotation with the datasheet, test certificates and shipping calculation.

Request a quotation: sales@chisen.cn
Technical and project discussion: jack@chisen.cn
WhatsApp: +86 131 6622 6999
Full specifications for this model: OPzV2-700 2V 700Ah product page
The complete tubular gel range: OPzV series overview
Need a supplier audit checklist or the cell datasheet pack? Ask for the audit checklist, IEC 60896 and DIN 40472 test reports, Eurobat classification and the full OPzV dimensional series with your enquiry.

For leadacidbattery.cn, browse the OPzV2-700 2V 700Ah tubular gel battery product page or contact us for a tailored quotation for your project.

Related CHISEN Buyer Guides

October 22, 2026