Batteries & Energy Storage
How do I size a battery for backup?
Reviewed by SolvSolar · Last reviewed:
Size a backup battery by listing the loads you must keep alive, multiplying by the hours of autonomy you need, then dividing by usable depth of discharge and inverter efficiency. For example, a 3 kW critical load for 4 hours is 12 kWh, which on LFP at 90% DoD and 95% inverter efficiency needs roughly a 14 kWh bank.