How to use this tool
Enter battery Wh, load watts and a loss allowance, then check the unit's continuous and surge ratings.
Enter your details
All defaults are editable planning assumptions. Use actual product specifications and site conditions where possible.
How the estimate works
Estimated hours = rated Wh × usable fraction × output efficiency ÷ (device watts + inverter idle watts).
Where product limits or site conditions matter, confirm them against the exact model and installation before buying.
Understanding your result
Rated battery watt-hours do not all reach the appliance. Inverter losses, low-load overhead and temperature affect usable energy, while compressors and motors can briefly demand far more than their running watts.
Choosing the right equipment
Check continuous and surge output ratings, the appliance’s plug and start-up demand, and the station’s manufacturer runtime chart if one is available. Consider how the station will be recharged during a long outage.