LiFePO4 is also called lithium iron phosphate or LFP. Battery energy and inverter power are separate ratings.
Capacity in kWh
Nominal energy = voltage × amp-hours ÷ 1,000. For example, a 51.2 V, 100 Ah battery holds 5.12 kWh nominally.
Usable energy by battery size
| Example | Usable energy | Delivered to appliances |
|---|---|---|
| 2.4 kWh | 1.9 kWh | 1.7 kWh |
| 5.0 kWh | 4.0 kWh | 3.6 kWh |
| 10.0 kWh | 8.0 kWh | 7.2 kWh |
These figures assume 80% usable capacity and 90% inverter efficiency.
Before you buy
- Check that the battery suits the inverter’s voltage and battery communication.
- Check for a suitable battery management system (BMS) and protection devices.
- Check the continuous and surge current for charging and discharging.
- Check the usable capacity, operating temperature and indoor or outdoor rating.
- Check the warranty terms, cycle test conditions and local service.
A 5 kWh battery does not automatically run a 5 kW load.