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How long will my battery last?

Estimate the runtime of an Arduino, ESP32 or sensor project from capacity (mAh) and average current, sleep mode included.

mAh
mA
mA
%
%
Average current
4.01 mA
Runtime
424.0 h · 17.7 days

Formula

Runtime = capacity × efficiency / average current

Average current blends active and sleep modes: Iavg = (Iactive × tactive + Isleep × tsleep) / period. 85% efficiency covers regulator losses and battery ageing.

Check your result in a real circuit

Wire the circuit in the Circuitly simulator and measure voltage and current with the multimeter — free, no account.

Open the simulator

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