GlenCalc

Battery runtime calculator

Enter the battery’s capacity and the power your devices draw.

About 50% for lead-acid, 80–100% for lithium.

Your answer

Runtime5 h 46 min
In hours5.76
Usable energy960 Wh

Worked out in your browser. Nothing you type is sent to a server.

How we worked it out

Updated as you change the numbers.

  1. Usable Wh = capacity × voltage × depth of discharge × inverter efficiency. Hours = usable Wh ÷ load watts.

Method and assumptions

Real runtime is a little lower at high loads (Peukert effect in lead-acid) and in cold weather.

Questions

How long does a 100 Ah 12 V battery run 150 W?

About 5 hours 46 minutes at 80% usable and 90% inverter efficiency.

Sources

Method and figures checked on . Every worked answer on this page is covered by an automated test. Found a mistake? Tell us.

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