Backup Power Battery Size Calculator

Use this for UPS, portable power station and battery-backup planning before checking surge and device-specific limits.

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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.

Privacy: All values stay in your browser.

What this test tells you

This test checks
  • Average load
  • Target backup duration
  • Entered delivery efficiency
How to read the result

Startup surge and inverter output limits must be checked separately.

Nominal Wh and usable delivered energy are not the same.