Work out energy and battery count from your average load, hours and battery specs.
How it works
Watts times hours gives watt-hours. Divide by usable depth of discharge and inverter efficiency, then by bank voltage for amp-hours.
Before you order
- Use a metered average for the load, since nameplate watts overstate most devices.
- Lead-acid batteries live longer at shallow discharge, and lithium usually allows deeper use.
- Battery capacity falls in the cold, so plan extra for garages and sheds.
Common questions
Series or parallel?
Series raises voltage and parallel raises amp-hours. Match battery type and age within a bank.
Does this cover inverter sizing?
No. Inverters are sized by peak watts, including motor starts, separately from energy storage.