Battery Runtime Calculator

Estimate portable operating time from battery capacity, transmit current, receive current, and duty cycle.

Estimate portable operating time

Enter your battery size, radio current draw, and operating mix to estimate how long a field or portable setup may run before hitting your reserve.

This calculator assumes a simple transmit/receive operating mix. Real runtime changes with battery age, temperature, radio efficiency, transmit power, and how closely your actual duty cycle matches the estimate.

Common operating styles

Load a practical field setup to compare portable runtime assumptions quickly.

Battery runtime results

20 Ah at 12.8 V
Estimated runtime
N/A
Usable operating time before reserve
Average current draw
N/A
Transmit and receive mix combined
Usable capacity
N/A
After reserve is held back
Usable energy
N/A
Based on voltage and usable capacity

Runtime summary

ItemValueWhy it matters

Operator notes

    About battery runtime

    Portable operating time is usually limited by average current draw, not just the battery label. POTA, SOTA, Field Day, and general field work often swing between brief transmit bursts and much longer receive periods, so the operating mix matters as much as the radio’s peak current number.

    This tool gives you a planning estimate so you can compare batteries, operating styles, and reserve margins before heading out. It is best used as a conservative starting point rather than an exact promise of runtime.