How Long Will a Power Station Run a Fridge?

A fridge is one of the best things to keep running in an outage, and also one of the easiest to estimate wrongly. The reason is that its label watts and its real daily energy use are very different numbers. This guide shows how to turn either one into a runtime for a portable power station, using the same 85% inverter-efficiency assumption as our runtime calculator. This is a research-based guide; we have not tested these runs ourselves.

How do you calculate fridge runtime?

Multiply the station’s capacity in watt-hours by 0.85 to allow for inverter losses, then divide by the fridge’s average draw in watts. That is hours of runtime for anything plugged into an AC outlet.

For a 1,070 Wh Jackery Explorer 1000 v2: 1,070 x 0.85 = 909.5 Wh usable at the outlet. At an average of about 43.8 W that is 909.5 / 43.8 = about 20.8 hours.

What is the difference between running watts and daily kWh?

A fridge’s compressor does not run all the time. It switches on until the inside is cold, then off, and repeats. While it runs, it draws its running watts. Averaged across a day, including the off periods (the duty cycle), the draw is much lower. The nameplate shows the running figure, while the EnergyGuide label shows a yearly kWh estimate that already includes the cycling.

The US Department of Energy cites average annual use (2016 data) of about 384 kWh for a consumer refrigerator and 588 kWh for a refrigerator-freezer. Divide by 365 days for a daily figure, and by 8,760 hours for an average wattage:

• 384 kWh a year is about 1.05 kWh a day, or an average of about 44 W.
• 588 kWh a year is about 1.61 kWh a day, or an average of about 67 W.

ENERGY STAR says certified refrigerators are about 9% more efficient than models meeting the federal minimum, and older units use more. Your own fridge may sit well outside these averages, so check its EnergyGuide label or manual.

How long will a 1 kWh, 2 kWh and 3.8 kWh station run a fridge?

Using the two averages above, after 85% inverter efficiency:

Station	Capacity	Usable at 85%	At 43.8 W average	At 67 W average
Jackery Explorer 1000 v2	1,070 Wh	909.5 Wh	20.8 h	13.6 h
Jackery Explorer 2000 v2	2,042 Wh	1,735.7 Wh	39.6 h	25.9 h
Anker SOLIX F3800	3,840 Wh	3,264 Wh	74.5 h	48.6 h

So a 1 kWh station does not quite cover a day for a typical fridge-freezer, a 2 kWh station covers one to two days, and a 3.8 kWh station gets you through a multi-day outage if nothing else is drawing power. Solar input can extend that; see the power station list for each model’s solar input and charge details.

Will the station start the compressor?

Runtime is only half the question. A compressor draws a short surge when it starts, higher than its running watts. The station must supply that surge as well as the continuous load. The Explorer 1000 v2 lists 1,500 W continuous and 3,000 W surge, the Explorer 2000 v2 lists 2,200 W continuous and 4,400 W surge, and the F3800 lists 6,000 W continuous and 9,000 W surge. Read your fridge’s manual for its running and startup watts, and plug in nothing else that you do not need.

Does a fridge need a UPS-style switchover?

No, a fridge tolerates a brief interruption well, and the compressor is built to restart. If you want to use a station as a plug-in backup for several devices, see our home backup list. To see how a larger unit would handle a whole-house load, read can a portable power station power a house.

What else can reduce fridge runtime?

Opening the door, a warm kitchen, a fridge that is old or very full of warm food, and anything else you add to the same station. Keep the door closed, and keep a thermometer inside so you can check food stays cold. Follow current food-safety guidance if the power is out for a long time.