This manual covers the safe installation, charging, operation, maintenance, and storage of ATB Power lithium iron phosphate (LiFePO₄ / LFP) battery systems with an integrated battery management system (BMS). Read it in full before installing or charging any battery.
Lithium Motive (LFP-M): LiFePO₄ monoblocs for floor care, MEWP/AWP, golf, and light utility, in 24V, 36V, 48V, and 72V systems.
Lithium ESS (LFP-E): LiFePO₄ rack and wall energy-storage systems for solar, backup, and off-grid (where supplied).
LiFePO₄ is one of the most thermally stable lithium chemistries, but a battery still stores significant energy. Installation and service must be performed only by trained personnel who have read and understood this manual. Keep this manual with the equipment.
Do not charge below 0°C. Do not exceed the rated charge voltage or current. Do not connect batteries of different voltage, capacity, age, or state of charge in the same bank. Do not use a lead-acid or unmanaged charger without an LFP profile. Do not defeat or bypass the BMS.
ATB lithium batteries use lithium iron phosphate (LiFePO₄) cells assembled into series/parallel monoblocs with an integrated battery management system (BMS). They deliver a flat discharge voltage, high usable capacity, fast charge acceptance, long cycle life, and a stable thermal profile, with no watering, no off-gassing, and no acid-spill risk.
The nominal cell voltage is 3.2 V. Cells are connected in series to build the system voltage: 8 cells (8S) for a 24 V system, 12S for 36 V, 16S for 48 V, and 24S for 72 V. Parallel groups increase capacity. Typical capacities range from about 105 Ah to 304 Ah per monobloc.
Every pack includes a BMS that protects the cells and balances them during charge. The BMS provides over-charge, over-discharge, over-current/short-circuit, and over/under-temperature protection, and disables charging below 0°C. See Section 7.
An ATB lithium monobloc is a managed system, not a bare battery. Always use a charger set to the correct LiFePO₄ profile and system voltage, and operate within the temperature and current limits on the product datasheet.
Store batteries indoors in a clean, dry, ventilated place, away from heat and direct sunlight. LiFePO₄ self-discharges slowly, but the BMS draws a small standby current, so a stored battery will gradually lose charge.
Storing a lithium battery fully discharged, or leaving it in deep over-discharge, can permanently damage the cells.
Correct installation is the first step to safe, long-life operation.
ATB lithium monoblocs are sized to common lead-acid footprints for direct upgrade. Lithium is lighter than the lead-acid pack it replaces; on counterbalanced machines, external counterweight compensation may be required to maintain the original machine stability. Confirm with the equipment manufacturer.
Incorrect series/parallel wiring can overload the BMS, cause uneven current sharing, and damage the batteries. If you are unsure whether a model can be banked, contact ATB Power before wiring.
Use a charger designed for LiFePO₄ set to the correct system voltage. A standard constant-current / constant-voltage (CC/CV) lithium charger is suitable. Lithium batteries do not need, and should not be given, a continuous float or equalization charge.
| System | Cells (S) | Nominal | Charge voltage | Discharge cut-off |
|---|---|---|---|---|
| 24 V | 8S | 25.6 V | 29.2 V | 20.0 V |
| 36 V | 12S | 38.4 V | 43.8 V | 30.0 V |
| 48 V | 16S | 51.2 V | 58.4 V | 40.0 V |
| 72 V | 24S | 76.8 V | 87.6 V | 60.0 V |
Per cell: nominal 3.2 V, charge 3.65 V, discharge cut-off 2.5 V. Always defer to the specific model datasheet where it gives different values.
Do not use a lead-acid charger profile, a desulfation/equalization mode, or an uncontrolled power supply. Do not exceed the charge voltage or current. Do not charge a battery that is damaged, swollen, or below 0°C.
LiFePO₄ delivers a flat voltage through most of the discharge, so equipment runs at near-full performance until the battery is nearly empty. Keep discharge within the rated current. Rated cycle life is at least 2000 cycles to 80% of nominal capacity at 80% depth of discharge under controlled conditions; actual life depends on depth of discharge, temperature, and charge management.
The flat LiFePO₄ discharge curve means resting voltage is a poor state-of-charge indicator. Use the BMS state-of-charge readout or a coulomb-counting gauge where available. The rest-voltage figures below are approximate only.
| State of charge | Per cell (rest) | 24 V system | 48 V system |
|---|---|---|---|
| 100% | ~3.40 V | ~27.2 V | ~54.4 V |
| 70% | ~3.30 V | ~26.4 V | ~52.8 V |
| 40% | ~3.25 V | ~26.0 V | ~52.0 V |
| 20% | ~3.20 V | ~25.6 V | ~51.2 V |
| 0% | ~2.50 V | ~20.0 V | ~40.0 V |
Approximate rest voltages for LiFePO₄ at 25°C after the battery has settled. Voltage under load reads lower. Do not rely on voltage alone to judge state of charge.
The integrated BMS continuously monitors cell voltages, current, and temperature, and balances the cells during charge. It will automatically protect the battery by disconnecting or limiting it when a limit is reached:
After a protection event, remove the cause (reduce load, warm or cool the battery, or apply a correct charge) and the BMS will normally re-enable the battery. Applying a charge is the usual way to recover from an under-voltage cut-off. If the battery does not recover, contact ATB Power.
ATB lithium batteries are maintenance-free in normal use. Periodic inspection keeps them safe and reliable.
| Symptom | Likely cause | Action |
|---|---|---|
| Will not charge | Battery too cold (<0°C); wrong charger; BMS fault | Warm battery above 0°C; use correct LFP charger/voltage; recycle charger power |
| Sudden loss of output | BMS over-current, over-discharge, or over-temperature cut-off | Reduce load, let temperature normalize, then recharge to reset |
| Short runtime | Low charge, cold temperature, ageing, partial charge | Fully charge; check temperature; check charger taper; test capacity |
| Battery seems dead / no voltage | Deep over-discharge; BMS in protection/sleep | Apply a correct charge to wake the BMS; if no recovery, contact ATB Power |
| Swelling, heat, odor, smoke | Cell damage or fault | Stop use immediately, isolate safely, do not charge, contact ATB Power |
The battery is hot, swelling, leaking, smoking, or making noise. Disconnect if it is safe to do so, move it away from combustibles and people, ventilate the area, and do not attempt to charge it.
Lithium iron phosphate batteries are regulated as Class 9 dangerous goods for transport (UN3480 for batteries shipped alone, or UN3481 for batteries packed with or installed in equipment). They must be shipped at a partial state of charge, protected against short circuit and damage, and packaged, marked, and labeled per the current ADR, IMDG, and IATA lithium-battery rules. Confirm requirements with your carrier before shipping. Do not ship a damaged or recalled battery without specialist advice.
| Parameter | Value |
|---|---|
| Chemistry | Lithium iron phosphate (LiFePO₄) |
| Cell nominal / charge / cut-off | 3.2 V / 3.65 V / 2.5 V |
| System voltages | 24 V (8S), 36 V (12S), 48 V (16S), 72 V (24S) |
| Standard / max charge current | 0.5C / 1C |
| Charging temperature | 0°C to +65°C (no charging below 0°C) |
| Discharging temperature | −35°C to +65°C |
| Storage temperature | −20°C to +45°C (≤1 mo); 0°C to +45°C (≤3 mo) |
| Recommended storage SOC | 40–60%; recharge every 3 months |
| Cycle life | ≥ 2000 cycles to 80% capacity (80% DoD) |
| Cooling | Passive (natural convection) |
| Float / equalization | Not used on lithium |
For model-specific values, banking approval, charger selection, or technical support, contact ATB Power at info@atbpower.com or atbpower.com. Operating the battery outside the conditions in this manual can shorten its service life.
This manual provides general guidance for ATB lithium iron phosphate (LiFePO₄) battery systems. Where a specific battery datasheet or label states different values for voltage, current, temperature, or torque, those model-specific values take precedence. Specifications are subject to change without notice. © 2026 ATB Power.