How long will a power station run a fridge?

The quick answer

Most full-size fridges use somewhere between 1 and 2 kWh a day. A power station can deliver roughly 85% of its rated capacity as mains power, after losses in its inverter. So:

Power station size	Fridge using 1.0 kWh a day	1.5 kWh a day	2.0 kWh a day
1 kWh (1,024 Wh)	about 21 hours	about 14 hours	about 10 hours
2 kWh (2,048 Wh)	about 42 hours	about 28 hours	about 21 hours
4 kWh (4,096 Wh)	about 3.5 days	about 2.3 days	about 1.7 days

Those are estimates for a fridge that’s kept closed most of the time in a normal room. A hot kitchen, a fridge that’s opened a lot, or an older model will shorten them.

Find your fridge’s real number

The figure that matters is energy per day, not the wattage on the back of the fridge. There are two easy ways to get it.

Read the label. In the US, the yellow EnergyGuide label (or the product listing) gives an estimated yearly use in kWh. UK and EU energy labels show kWh per year too. Divide by 365 for a daily figure. A fridge rated at 600 kWh a year uses about 1.6 kWh a day.

Measure it. A plug-in energy meter is cheap, often under $30 or £20. Plug the fridge into it and read the total after 24 hours. That captures your kitchen, your settings and your habits, which a label can’t.

Then the sum is simple:

runtime in hours = station capacity (Wh) × 0.85 ÷ (daily kWh × 1,000 ÷ 24)

For a 1,024 Wh station and a fridge using 1.6 kWh a day: 1,024 × 0.85 = 870 Wh usable, and 1,600 ÷ 24 = 67 W average, so about 13 hours.

Why a fridge uses less than its rated wattage

A typical fridge compressor draws something like 100 to 200 W while it runs. But it doesn’t run all the time. It switches on until the inside is cold enough, then rests, and over a day it might run a third to half of the time. That’s why the average draw of a fridge using 1.2 kWh a day is only about 50 W.

This cycling is also why runtime estimates based on the compressor’s wattage come out far too pessimistic. A fridge that really drew 150 W around the clock would use 3.6 kWh a day, about three times what a typical modern model uses.

Some features push the average up: ice makers and water dispensers, automatic defrost heaters, and very warm rooms. Garage fridges in summer are the worst case.

The startup surge

Every time the compressor starts, it draws a brief spike of current, often several times its running power for a fraction of a second. Older fridges have the biggest spikes. Newer models with inverter compressors start more gently.

This matters for small power stations. A unit rated at 300 W can trip when a fridge kicks in. Current 1 kWh models are rated well above that: the EcoFlow DELTA 3 Plus lists 1,800 W continuous with a 3,600 W surge, and the Jackery Explorer 1000 v2 lists 1,500 W. Either handles a household fridge comfortably.

Make the battery last longer

• Keep the door shut. Group your trips to the fridge.
• Fill the empty space. Bottles of water or ice packs hold the cold and help the compressor rest longer.
• Check the temperature setting. About 37 to 40°F (3 to 4°C) is enough. Colder settings just use more energy.
• Turn off what you don’t need. Ice makers and water dispensers can be switched off for the duration.
• Check the AC timeout. Some power stations switch their AC output off automatically when the load is low. A fridge in its resting phase draws almost nothing, so make sure that setting is off, or you’ll come back to a warm fridge and a full battery.
• Turn off unused outputs. The inverter itself uses some power. If you’re only running the fridge, switch off the station’s DC and USB outputs.

Real runtimes are often a little shorter than the formula, because the inverter’s own consumption weighs more when the load is small. Treat the tables above as a best case.

Adding solar panels

Pair a power station with portable panels and you can stretch an outage from a day to several. A rough guide: each 100 W of panels gives about 0.3 to 0.4 kWh on a sunny day after losses, less in winter or under cloud. To replace a fridge’s 1.2 kWh a day, you’d want roughly 300 to 400 W of panels in a sunny spot.

Most 1 kWh stations accept somewhere between 400 and 1,000 W of solar input, so the station is rarely the limit. Space and sunshine usually are.

What about the freezer?

A freezer copes with a power cut better than a fridge. According to FoodSafety.gov, a full freezer holds a safe temperature for about 48 hours with the door closed, or 24 hours if it’s half full. A fridge keeps food safe for up to 4 hours. After that, perishable food such as meat, fish, eggs and leftovers should be thrown out.

So if your power station is small, the fridge is the one to keep running. You can leave a full freezer closed for the first day and only connect it if the outage drags on.

Which size should you buy?

• For a few hours at a time (short outages, keeping food safe until power returns), 1 kWh is enough for most fridges.
• For a full day or overnight, aim for 2 kWh, or 1 kWh plus solar panels.
• For multi-day outages, or a fridge plus a freezer plus a few lights and a router, look at 3 to 5 kWh models or expandable systems. Our guide to home battery backup covers the bigger options.

For specific models at each size, see our best portable power stations, and for a side-by-side look at two of the most popular brands, EcoFlow vs Jackery.