Battery Capacity Calculator

Size Ah and Wh from load, hours, and days of autonomy.

Load watts (W)

Hours per day (h)

Chemistry

System voltage

Days of autonomy

Estimates only. Verify with local codes, manufacturer specs, and a qualified installer.

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Continue sizing with a related tool.

How long will your battery run a given load?

Battery Wh and Ah from daily load and backup days.

Series/parallel bank voltage, Ah, and Wh.