Description
The LiFePro 18kWh long-duration battery is a 51.2V, 345Ah LiFePO4 storage battery for off-grid homes, cabins, tiny homes and larger standalone solar systems. It combines approximately 17.66kWh of nominal energy with a deliberately moderate charge and discharge limit, making it better suited to long-duration energy storage than high power from a single battery.
Important power limit
The 100A JK BMS is programmed to a maximum of approximately 86A charge and discharge (0.25C). That is about 4.4kW at nominal voltage. For system planning, allow approximately 4kW continuous power per battery. A single battery is not intended to support an 8kW, 12kW or 16kW inverter at full output.
Built for long-duration off-grid storage
At a 4kW load, the battery contains roughly four hours of nominal stored energy before allowing for inverter losses, operating reserve, temperature and BMS settings. This makes it a practical choice where overnight energy capacity and moderate daily cycling matter more than very high instantaneous output.
- Large 17.66kWh nominal capacity: a 16-cell, 51.2V pack using 345Ah prismatic LiFePO4 cells.
- Conservative current setting: the approximately 86A limit reduces the electrical and thermal demand on each battery compared with a higher-current model.
- JK inverter BMS: includes 2A active balancing plus CAN and RS485 communications. Protocol selection and inverter commissioning must be confirmed for the exact installation.
- Serviceable construction: the enclosure can be inspected and serviced by LiFePO4 Australia or another suitably qualified battery technician rather than relying on a permanently sealed pack.
- Expandable: identical batteries can be connected in parallel when the busbars, protection, cabling, BMS communications and inverter settings are designed for the combined bank.
How many batteries does an off-grid system need?
The table below is a conservative starting point based on approximately 4kW continuous power per battery. Battery quantity must also cover the required usable energy, inverter surge current, days of autonomy and expected solar recharge.
| Battery quantity | Combined nominal energy | Planning power allowance | Typical design context |
|---|---|---|---|
| 1 | 17.66kWh | Up to approximately 4kW | Long-duration storage with moderate loads |
| 2 | 35.33kWh | Up to approximately 8kW | Larger home systems and higher simultaneous loads |
| 3 | 52.99kWh | Up to approximately 12kW | High-energy off-grid homes and workshops |
| 4 | 70.66kWh | Up to approximately 16kW | Large engineered standalone systems |
These figures assume identical batteries, balanced current sharing and correct system design. Actual usable energy and output depend on inverter efficiency, reserve settings, temperature, cabling, protection and BMS configuration. Do not select battery quantity from inverter nameplate power alone.
Inverter compatibility
The JK inverter BMS supports communications used with a range of Victron, Deye and Growatt systems. Compatibility is not automatic: the correct communications cable, BMS protocol, inverter firmware and charge settings must be selected and commissioned for the exact equipment.
For an inverter larger than approximately 4kW, or for loads with high starting current such as pumps, compressors and workshop equipment, contact us before ordering. We can help determine whether this long-duration version or a higher-current battery is the better fit.
Installation and protection
This is a heavy, low-voltage DC battery intended for a properly designed off-grid energy system. Installation must include correctly rated DC over-current protection, isolation, busbars, cabling, earthing and enclosure clearances appropriate to the full prospective current of the battery bank.
The integrated single-pole circuit breaker does not replace any external protection or isolation required by the system design. Internal servicing should only be performed after safe isolation by a competent person familiar with high-current lithium battery systems.
Up to 15 batteries may be configured in parallel where supported by the final design. Banks of this size require specialist engineering, equal-current-path design, high-interrupt protection and careful commissioning. Please discuss any system above four batteries with us before purchase.
Australia-wide delivery
We can arrange heavy-battery freight throughout Australia. Delivery is normally to an approved freight depot or a commercial address with suitable unloading equipment. Ask us for a freight quote with your suburb or postcode, quantity and delivery facilities; we can usually provide a quote within a few hours during business hours.
Specifications
| Battery and construction | |
|---|---|
| Brand | LiFePro |
| Chemistry | Lithium iron phosphate (LiFePO4) |
| Cell configuration | 16-series, 345Ah prismatic cells |
| Nominal voltage | 51.2V DC |
| Nominal capacity | 345Ah |
| Nominal energy | 17.66kWh (marketed as 18kWh) |
| Battery dimensions | 750 × 439 × 252mm |
| Approximate battery weight | 110kg |
| Packaged freight allowance | 120kg; 800 × 600 × 500mm |
| Enclosure rating | IP21 — install in a protected, dry location |
| Integrated protection | Single-pole circuit breaker plus JK BMS protections |
| Electrical limits and BMS | |
| Operating voltage range | 46–58.4V DC |
| Maximum charge voltage | 58.4V DC |
| Recommended charge target | 56.8V DC, subject to final system settings |
| BMS hardware rating | 100A |
| Programmed charge/discharge limit | Approximately 86A (0.25C) |
| Power at programmed limit | Approximately 4.4kW at nominal voltage; use approximately 4kW per battery for planning |
| Active balancing | Up to 2A |
| Communications | CAN, RS485 and Bluetooth monitoring |
| Parallel capability | Up to 15 identical batteries, subject to engineered system design and commissioning |
| Environmental limits | |
| Operating temperature | 0°C to 55°C |
| Charging temperature | 2°C to 45°C |
Specifications describe the current product configuration and may be refined as components or firmware are updated. Confirm inverter compatibility, included cables and final settings before ordering.
