power test
Backup Power Battery Size Calculator
Use this for UPS, portable power station and battery-backup planning before checking surge and device-specific limits.
No accountLocal where possibleRetest anytime
Backup battery size
Use this for UPS, portable power station and battery-backup planning before checking surge and device-specific limits.
This is a planning/compatibility calculation from the values you enter. DeviceOK does not claim to read charger protocols, battery health, cable electronics or mount certification from your browser.
Private by design
All values stay in your browser.
Use the result as evidence, not a guess.
This test checks
- Average load
- Target backup duration
- Entered delivery efficiency
How to read it
Startup surge and inverter output limits must be checked separately.
Nominal Wh and usable delivered energy are not the same.