Tool

Portable power station runtime calculator

Runtime is estimated as battery capacity times usable-capacity factor, divided by load watts and duty cycle.

The default uses an 85% usable-capacity assumption to account for inverter loss and real-world overhead. Treat the result as a planning estimate, not a guarantee for medical, safety, or unattended backup loads.

Runtime formula

estimated hours = capacity Wh × 0.85 ÷ load watts ÷ duty cycle

ExampleInputEstimated result
Router and laptop1024 Wh, 80 W, 100% dutyAbout 10.9 hours
Fridge with cycling compressor1024 Wh, 150 W, 50% dutyAbout 11.6 hours
Small heater or kettle1024 Wh, 900 W, 100% dutyAbout 1.0 hour