Short answer: runtime in hours is roughly battery watt-hours x 0.85 / load watts. A 1,000 Wh station running a steady 100 W load lasts about 8.5 hours on that assumption. Use the calculator to try your own devices and station.

1. Pick the devices you would run

The watt figures are round placeholders for planning, not measurements. Replace each with the number on your device label or a plug-in watt meter. Without JavaScript, use the static table below.

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2. Enter the power station
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Default 85% is a conservative planning assumption. Jackery says inverter efficiency typically ranges from 85 to 95%. Real efficiency varies by load and model.

How the estimate works

The calculator multiplies the station’s rated capacity in watt-hours (Wh) by an inverter-efficiency figure, then divides by the total watts of the devices you run at the same time. The default of 85% is a conservative planning assumption, not a measurement of any particular model. Jackery states that inverter efficiency typically ranges from 85 to 95% and that conversion losses consume roughly 5 to 15% of stored energy. Change the percentage in the calculator if your station’s manual gives a different figure.

The estimate leaves out several things that usually make real runtime shorter: idle draw while the AC outlets are on, cold or hot batteries, battery aging, and appliances that cycle on and off. Devices powered through USB or DC ports skip the inverter, so they can run longer than the AC figure suggests. Treat the answer as a planning number and keep a margin.

Example runtimes at 85% efficiency

Hours of runtime for a steady load, using the formula above. The capacities are round example sizes, not specific models. Check a real station’s rated Wh on its maker page.

Steady load 300 Wh 500 Wh 1,000 Wh 2,000 Wh 4,000 Wh
20 W 12.8 h 21.2 h 42.5 h 85.0 h 170 h
50 W 5.1 h 8.5 h 17.0 h 34.0 h 68.0 h
100 W 2.5 h 4.2 h 8.5 h 17.0 h 34.0 h
200 W 1.3 h 2.1 h 4.2 h 8.5 h 17.0 h
500 W 0.5 h 0.8 h 1.7 h 3.4 h 6.8 h
1000 W 0.3 h 0.4 h 0.8 h 1.7 h 3.4 h

Refrigerators, furnace blowers and other motors cycle on and off and can draw more at startup, so use the label’s running watts for the average and compare the startup figure with the station’s surge rating. Heating appliances such as space heaters draw so much that small stations cannot sustain them.

From runtime to a station

Once you know the hours you need, multiply your load watts by the hours and divide by 0.85 to get the minimum capacity in Wh. Then check that the station’s rated AC output is higher than your total watts. Our model-specific guides apply the same arithmetic:

Sources