OPzS2-3000 2V3000Ah Flooded Tubular Battery: Utility DC Strings Built Like Power-Plant Hardware

Answer First

The OPzS2-3000 2V3000Ah is a 2 V, 3,000 Ah nominal flooded tubular lead-acid cell rated at the 10-hour rate (C10, 1.80 V per cell cut-off), published at 576 × 212 × 771 mm with 826 mm height over terminals, a Φ20-M8 bolt terminal torqued to 10–12 N·m, float voltage 2.23 V per cell at 25 °C, equalise 2.35 V per cell, temperature compensation of −3 mV per °C per cell, maximum charging current 600 A, an internal resistance of approximately 0.24 mΩ, and a designed floating life of 20+ years at 20 °C. Each cell weighs 155 kg without electrolyte and 218 kg with it. Treat it as a power-plant component, not a battery box: one 108-cell string delivers 648 kWh nominal at 216 V DC, and every procurement decision — string architecture, floor loading, ventilation, float current, inspection regime, end-of-life capacity spread — follows from that single fact.

Key Takeaways

• String energy is the unit of purchase. 54 cells × 2 V × 3,000 Ah = 324 kWh; 108 cells = 648 kWh; 190 cells = 1,140 kWh. A 108-cell string of the OPzS2-3000 2V3000Ah carries roughly 600 kW of float-regulated standby capacity behind 107 interconnect joints, versus more than 200 joints and twice the cell count if the same duty is split into 1,500 Ah cells on two parallel strings.
• Mega cells move cost from cells into the room. Fewer strings means fewer racks, fewer busbar runs, fewer monitoring channels, fewer points of human error during installation — and a structural floor that must be designed for the concentrated mass rather than for scattered small units.
• Float current is a design load, not a rounding error. At the conventional 5 mA per Ah float rule, a 3,000 Ah cell draws roughly 15 A (derived). Across a 108-cell string that is about 3.6 kW of continuous float power and a charger that must absorb 600 A per cell at the published maximum charging current.
• Flooded means flooded. Vented electrolyte means hydrogen evolution, a designed ventilation path, periodic watering, specific-gravity inspection, and a battery room rather than a sealed cabinet — unless the same duty is met with a containerised arrangement where the environment can be conditioned.
• The published record is specific and worth reading closely. IEC 60896-11:2002, DIN 40736-1:1985, GB/T 19638.2-2014, YD/T 1360, Eurobat Long Life, BS 6290 Part 4 and UL 1989 are listed; the published page does not state cell weight, so any floor-loading calculation must start with a confirmed weight from the supplier rather than an assumption.

§1 — OPzS2-3000 2V3000Ah Quick Specifications Table

Each row states its source. Datasheet is the manufacturer specification sheet for the OPzS2-3000 and is the authority for weights, voltages, compensation and designed life. Model page is the published CHISEN product page. Arithmetic rows show the derivation in the cell.

Published specifications, certificates and the model page for the OPzS2-3000 2V3000Ah are available at OPzS2-3000 2V3000Ah model page. The wider flooded tubular range, including smaller frame sizes on the same OPzS platform, is listed at OPzS flooded tubular battery series.

§2 — The Pain

The failure mode in large DC installations is not the cell. It is the string, the room, and the paperwork around the room.

The OPzS2-3000 is a power-plant component: 576 mm long, 212 mm wide, 771 mm of body and 826 mm over the terminals, with a Φ20-M8 terminal torqued to 10–12 N·m and a published maximum charging current of 600 A. Engineers who have spent their careers with 12 V blocks or with 100 Ah VRLA units tend to mis-size the surrounding system when they first see a cell like this. The physics is the same; the scale is not.

Three pain points recur. First, string count. A 324 kWh duty built from 54-cell strings needs two strings where a 648 kWh string needs one, and every additional string multiplies interconnects, rack tiers, busbar terminations, monitoring channels and the number of joints somebody has to torque correctly at commissioning. Second, floor loading and battery-room design. The concentrated mass of a 108-cell string of 3,000 Ah cells has to be carried on a designed plinth with a load path, not on a slab that was sized for a handful of small units; the published model page does not state cell weight, so this number must be obtained from the supplier before any civil drawing is issued. Third, the flooded reality: vented electrolyte, hydrogen evolution on overcharge, a ventilation design governed by the applicable standard, periodic watering, and a specific-gravity inspection regime that has to be staffed for twenty years.

The commercial consequence is that the buyer who treats the OPzS2-3000 2V3000Ah as a drop-in box ends up paying twice — once for the cells, and again for the room, the string design and the service contract that the cell format demands.

§3 — The Choice

The real alternative is not lead-acid versus lithium. In most of the markets where this cell is specified — telecom power rooms in Mumbai and Karachi, port substations at Jebel Ali and Port Said, containerised renewables at Santos and Callao, harbour cranes and rail traction auxiliaries at Chattogram, Mombasa, Durban and Dar es Salaam — the real alternative is the same chemistry arranged differently: one large cell versus many smaller ones on the same OPzS platform.

For the same 648 kWh DC duty, the arithmetic is stark.

The mega cell wins on joints, rack tiers, floor area per kWh and monitoring complexity. It loses on failure granularity: one cell out of 108 is nearly 1% of the duty, so end-of-life capacity spread and cell-to-cell matching have to be managed deliberately rather than left to average out across 216 units. It also demands a bigger charger and a bigger structural plinth. Neither option is free.

Every rate in that TCO table is an explicit planning placeholder, not a quotation: the cell cost, the joint rate, the channel rate and the inspection rate must be replaced with your own landed and labor numbers before the table goes into a business case. The structural point holds regardless of the rates. Labor and monitoring scale with cell count and joint count; cells installed per kWh does not improve when you subdivide the string. That is the argument for the OPzS2-3000 2V3000Ah in any installation where the battery room has to be staffed for the life of the plant.

The second comparison is against valve-regulated and sealed chemistries on the same duty.

For a rail traction auxiliary application or a utility-scale renewable plant where the same DC bus is fed by an inverter and the battery sits at the base of a turbine or a substation, the flooded cell’s 20-plus-year float life and its tolerance of a wide temperature band usually decide the question. In a containerised installation, the ventilation and watering regime can be handled inside the enclosure — which is exactly why containerised versus room installation has to be decided early rather than at the shipping date.

§4 — The Framework

Seven criteria decide whether the OPzS2-3000 2V3000Ah belongs in your project. Apply them in this order.

1. String architecture before cell count. Fix the DC bus voltage first — 108 V, 216 V, 384 V or 480 V — and then the string energy: 54 cells at 324 kWh, 108 at 648 kWh, 190 at 1,140 kWh. Buying the cell before fixing the string is how buyers end up with a set of cells that cannot be arranged into a clean string architecture. The published OPzS range covers the frame sizes around the 3,000 Ah cell if a different string energy is required.

2. Physical and structural envelope. 576 × 212 × 771 mm, 826 mm over terminals, 155 kg per cell without electrolyte and 218 kg with it. Confirm rack pitch, aisle width, door clearances and the lifting route for a single cell before the plinth is poured. Cell weight is not published on the model page, so obtain the certified weight per cell and confirm the floor loading and the seismic restraint arrangement with a structural engineer. Do not substitute a guess.

3. Charge acceptance and charger sizing. Maximum charging current 600 A per cell is published. That number dictates the rectifier size, the busbar cross-section and the cable derating for the equalise scenario, not just the float scenario. It also dictates the equalise window you can actually run at 2.35 V per cell, or 2.40 V per cell in the solar and wind settings.

4. Thermal and float regulation. Float 2.23 V per cell at 25 °C with −3 mV/°C/cell compensation, equalise 2.35 V per cell, with −4 mV/°C/cell compensation in the solar and wind settings. Verify the charger you are pairing supports both, and verify the compensation slope matches the published values. Mismatched compensation is the most common cause of early capacity loss in flooded installations and it is entirely avoidable.

5. Ventilation and hydrogen. Vented cells evolve hydrogen on overcharge. A first-order worst case using Faraday’s law at 25 °C is roughly 0.46 L of hydrogen per hour per amp of charging current per cell; at the derived 15 A float current per 3,000 Ah cell that is about 6.9 L/h per cell, or roughly 740 L/h across a 108-cell string before any allowance for oxygen recombination. Treat that as an order-of-magnitude design check, then design ventilation to the applicable standard rather than to the estimate. The key operating rule is to keep the float and equalise programme inside the ventilation envelope, not to ventilate for an equalise event.

6. Service regime and end-of-life behaviour. Electrolyte is liquid, with published specific gravity of 1.24 ± 0.01 g/cm³ fully charged. That means watering intervals, specific-gravity readings, temperature-compensated readings and a written inspection record are part of the asset, not optional extras. Ask for the end-of-life capacity spread the cell is warranted to and for the cell-to-cell matching data shipped with the batch. Ask for it as a certificate, because it is the only evidence that the 108 cells you receive were matched when they were made.

7. Evidence and service life. The published compliance set — 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, plus IMDG Class 8 and UN2794 transport classification — is the minimum paper pack you should require, together with a factory weight and a type-test report. CHISEN’s manufacturing and quality background is described at CHISEN company profile. If a supplier cannot produce that pack for a 3,000 Ah cell, the plant will not produce it for you either.

§5 — The Trust

Most procurement disputes in this category do not start with chemistry. They start with documentation that was never requested, and end with a battery room that cannot prove what was installed.

The capacity rating is not a usable capacity rating. The published 3,000 Ah is a C10 figure at 1.80 V per cell cut-off, measured on new cells at 25 °C. Your DC duty may be a 30-minute duty, a one-hour duty, or a continuous float duty. Ask the supplier for discharge curves at your actual duty cycle and your actual end-voltage, and ask how the cell performs at the low end of the published charge range of −20 °C to 65 °C. A 3,000 Ah cell that delivers less than rated capacity at 0 °C is normal chemistry, not a defect — but it must be priced into the design, not discovered in year three.

Cell weight is published. The manufacturer datasheet gives 155 kg per cell without electrolyte (342 lbs) and 218 kg with electrolyte (481 lbs), with 63 kg of acid per cell. A 108-cell string is therefore roughly 16.7 t of dry cells and about 23.5 t filled, which is what sizes the plinth and the floor loading. Internal resistance is approximately 0.24 mΩ fully charged at 20 °C. Confirm the filled mass against your own delivered batch before the rack is ordered.

Matching certificates are the real warranty. With a mega cell, one unit out of 108 carries nearly 1% of the duty (derived). At end of life, capacity spread across the string is what determines whether the string can carry its load, so the batch-level matching data, the cell-to-cell voltage and specific-gravity records at delivery, and the acceptance test protocol should all be contractual deliverables. Without them, a warranty claim becomes an argument about which cell was weak, and you will lose that argument without data.

Ventilation is a compliance item, not an engineering nicety. Vented electrolyte plus a 600 A maximum charging current means hydrogen is a permanent feature of the room. The published discharge and charge temperature ranges are wide, and in a hot climate a battery room without forced ventilation will run at the top of the charge range. Design the room for the worst case, not the average case.

Containerised versus room installation. Containerised installation concentrates the problem: a sealed enclosure holding flooded cells needs a controlled atmosphere, spill containment, and access for watering and SG inspection — and a 108-cell string still weighs what it weighs. Room installation spreads the load and gives natural ventilation. Neither is a default choice; both need a structural and HVAC input from a firm that has actually built a flooded room at this scale.

The written record matters for the plant’s whole life. Keep the delivery record, the torque record at commissioning (10–12 N·m on a Φ20-M8 terminal), the electrolyte level and SG readings, the equalise log, the ventilation commissioning record, and the string voltage trends. Twenty years of float life is only meaningful if the asset is monitored. Ask for the monitoring and recording regime, the protocol for a single-cell replacement in the middle of a string, and the local service response in the country where the battery actually stands — Lagos/Apapa, Tema, Mombasa, Durban, Jebel Ali, Karachi, Chattogram, Santos, Callao, Port Said, Valencia, Hamburg, Rotterdam, Gdansk, Mersin, Manila, Jakarta, Ho Chi Minh.

Two traps worth naming. First, the OPzS flooded platform and the OPzV gel platform are not interchangeable in the string: gel is valve-regulated and needs no watering, flooded needs watering and inspection, and the float/equalise programmes differ. Specify the platform, not just the amp-hour rating. Second, a cell is not a battery. A 3,000 Ah cell with a transparent SAN container is a component that arrives as part of a string with busbars, racks, insulators, torque hardware, drainage, spill containment and a charger. Contracts written around “3,000 Ah cells, 108 off” that omit the string hardware and the room scope are the single most common source of variation in landed cost on this product.

§6 — FAQ

Q1. What is the OPzS2-3000 2V3000Ah rated capacity and how is it measured? 3,000 Ah nominal at the C10 rate — the 10-hour rate with a 1.80 V per cell cut-off — on a 2 V cell. Published by CHISEN on the model page. Any usable-capacity claim for your duty cycle needs the supplier’s discharge curves.

Q2. How much energy is one string of these cells? 54 cells × 2 V × 3,000 Ah = 324 kWh; 108 cells = 648 kWh; 190 cells = 1,140 kWh (derived from the published 2 V / 3,000 Ah rating). At 108 cells the string is 216 V DC at 3,000 Ah, which is the usual starting point for a 216 V DC utility bus.

Q3. What are the physical dimensions and the installation footprint? 576 × 212 × 771 mm per cell, 826 mm over terminals (published). Cell footprint is 0.122 m² (derived). For 108 cells on a single tier that is about 13 m² of cell footprint before aisles, access and the busbar zone; plan the room from the rack layout, not from the cell footprint alone.

Q4. What is the float and equalise voltage, and does temperature compensation matter? Float 2.23 V per cell at 25 °C with −3 mV/°C/cell compensation; equalise 2.35 V per cell at 25 °C, with −4 mV/°C/cell compensation in the solar and wind settings (published). Verify your charger implements both slopes. Wrong compensation is the most common preventable cause of early capacity loss.

Q5. How much float current does a cell draw, and what does that do to the charger? At the conventional 5 mA per Ah float rule, a 3,000 Ah cell draws about 15 A (derived), which is roughly 3.6 kW across a 108-cell string at 2.23 V per cell. The published maximum charging current is 600 A per cell, and that figure — not the float figure — sizes your rectifier, busbars and cables.

Q6. Does a flooded 3,000 Ah cell need ventilation? Yes. Vented cells evolve hydrogen on overcharge; a first-order Faraday estimate is about 0.46 L/h per amp of charging current per cell at 25 °C, or roughly 740 L/h across a 108-cell string at 15 A float current per cell, before any recombination credit. Design to the applicable standard, not to the estimate, and keep the equalise programme inside the ventilation envelope.

Q7. How often do these cells need watering and inspection? They need it; the interval depends on temperature, discharge depth and charging regime. The electrolyte is liquid with a published specific gravity of 1.24 ± 0.01 g/cm³ fully charged, so temperature-compensated SG readings are the measurement that matters. A 108-cell string of 3,000 Ah cells means fewer watering events per unit of capacity than 216 smaller cells, but each event involves handling a much larger volume.

Q8. What is the float life and the cycle life? Float life 20+ years at 20 °C (published) — the same datasheet’s temperature-versus-float-life curve gives roughly 15–16 years at 25 °C, so 20 °C is the condition to design to. Cycle life 1,500–2,500 cycles at 80% DoD, 2,500–4,000 at 50% DoD, 4,500–6,500 at 30% DoD (published). Float life assumes float service at 25 °C with correct compensation and a maintained inspection regime.

Q9. Which certifications and transport approvals are available? IEC 60896-11:2002, DIN 40736-1:1985, GB/T 19638.2-2014, YD/T 1360, Eurobat Long Life, BS 6290 Part 4 and UL 1989, with IMDG Class 8, UN2794 and MSDS for transport (published). Pre-shipment inspection reports from SGS, TUV, BV and CTI are available, as are destination-country certifications such as SONCAP, PVOC, SASO, BIS and ESMA on request.

Q10. Is this suitable for rail traction auxiliary or utility-scale renewable duty? Yes, where the duty is float-dominated with occasional deep discharge. The 1,500–2,500 published cycles at 80% DoD suit auxiliary and backup duty rather than traction propulsion duty, and the wide published temperature range helps in unconditioned plant rooms from Ho Chi Minh to Rotterdam. For utility-scale renewables paired with an inverter, size on the DC duty cycle and confirm the discharge curve at your actual end-voltage.

Expert Summary

The OPzS2-3000 2V3000Ah is a 2 V, 3,000 Ah flooded tubular lead-acid cell rated at C10 with a 1.80 V per cell cut-off, measuring 576 × 212 × 771 mm with 826 mm over terminals, using a Φ20-M8 terminal torqued to 10–12 N·m, floating at 2.23 V per cell at 25 °C with −3 mV/°C/cell compensation, equalising at 2.35 V per cell with −4 mV/°C/cell compensation in the solar and wind settings, accepting a published maximum charging current of 600 A, delivering 1,500–2,500 cycles at 80% DoD and a designed floating life of 20-plus years at 20 °C. Its significance is architectural: 54 cells give 324 kWh, 108 cells give 648 kWh and 190 cells give 1,140 kWh (derived), so a 3,000 Ah cell should be engineered as a power-plant component. One 108-cell string carries the duty with 107 series interconnects against 214 for two parallel 1,500 Ah strings, 108 monitoring channels against 216, and roughly 34% lower illustrative 15-year cost when labor, monitoring and inspection are counted — but it concentrates failure granularity to 0.93% of duty per cell, so batch matching data, certified cell weight, a designed plinth, hydrogen ventilation sized for a permanent float load, and a twenty-year inspection and watering regime are not optional. Full published specifications sit on the model page; comparable frame sizes cover adjacent string energies in the OPzS flooded range.

Contact CHISEN — 24-Hour Response

Send us the following and we will return a sizing sheet within one business day: your DC bus voltage, the load in kW, backup autonomy in hours or minutes, the duty cycle (float only, or float plus deep discharge), the number of parallel strings, the installation environment (room or container, indoor or outdoor, ambient temperature range), the ventilation standard you work to, and the destination port or city — Shanghai, Ningbo, Mumbai, Jebel Ali, Santos, Karachi, Mombasa, Rotterdam or otherwise. We will return the string architecture, the cell count, the charger sizing against the published 600 A maximum charging current, the floor-loading and ventilation preliminary note, the certification pack, and a landed-cost basis you can put next to your own numbers.

• WhatsApp: https://wa.me/8613166226999
• Email: sales@chisen.cn
• Model page: OPzS2-3000 2V3000Ah specifications
• Related reading: OPzS flooded tubular battery series and CHISEN company profile

For further technical pages and application guides, visit leadacidbattery.cn.

CHISEN Battery Team

Engineering and export team at CHISEN Battery, Hangzhou, China. Lead-acid and lithium battery manufacturer, ISO 9001 / CE / UL certified, exporting to 50+ countries.

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