Battery backup runtime calculator
Work out how long a home battery can keep your essentials running in a power cut, before any solar recharge.
Estimated backup time
21 h 52 min
10.9 kWh reaches your appliances after the reserve and inverter losses.
Add the power of everything that must stay on.
| Stored energy available | 12.2 kWh |
|---|---|
| Energy reaching appliances | 10.9 kWh |
| Continuous essential load | 500 W |
| Cost to recharge | £3.20 |
How we calculated this
Available battery energy is capacity after the reserved share. Energy reaching the home is that amount after inverter losses.
Runtime is usable energy divided by the continuous load. Motors, pumps and compressors can draw a much higher surge when they start, which this estimate does not model.
The recharge cost prices the energy removed from the battery at your current electricity rate and excludes charging losses.