Power Station Runtime Calculator

Estimate how long a portable power station can run an appliance, using either the manufacturer rated capacity or an independently measured usable capacity. Pick a product from our evidence database or enter values by hand.

1 · Power station

Choose a product (fills verified values, labelled by evidence type) — or leave on manual

Capacity to use

Battery capacity (Wh)

Rated to usable factor (%) estimate

2 · Appliance

Appliance power draw (watts)

Presets are typical values only — consumption varies by model. Adjust to your appliance rating plate.

Advanced: duty cycle and starting surge

Duty cycle (%) for cycling appliances

Appliance starting surge (W) optional

A continuously running heater is 100%. Some refrigerators run roughly 30-50% depending on conditions — there is no single universal figure.

3 · System and other loads

System efficiency (%) estimate

Additional continuous load (W) idle draw, router…

This calculator provides an estimate only. Actual runtime varies with inverter efficiency, battery temperature, appliance cycling, battery age, firmware, cable losses, power-station idle consumption, and appliance starting surge. It is not a guarantee of appliance compatibility.

How the runtime is calculated

With rated capacity: runtime = rated Wh × usable-factor × efficiency ÷ total average load. With an independently measured usable capacity, no second loss estimate is applied: runtime = measured Wh × efficiency ÷ total average load. Total average load = (appliance watts × duty cycle) + additional continuous load. Manufacturer figures are labelled claims; measured figures name their source.