How Long Will a Power Station Run a Refrigerator? (The 3-Step Math)

Step 1: Find your fridge's average watts

The best number to use is on the yellow EnergyGuide label that comes with every new refrigerator sold in the US. It shows the model's estimated yearly electricity use in kWh, measured with a standard test procedure. If you've lost the label, search your model number plus "EnergyGuide"; manufacturers publish them as PDFs.

Convert yearly kWh into average watts:

Average watts = yearly kWh × 1,000 ÷ 8,760 hours

For example, the Department of Energy's Building America Solution Center shows a refrigerator EnergyGuide label estimating 630 kWh per year, about 1.7 kWh per day. That's 630 × 1,000 ÷ 8,760 ≈ 72 W on average.

Why not use the wattage on the nameplate? The DOE notes that nameplate wattage is the maximum the appliance can draw, so using it overestimates real-world use. A fridge's compressor runs in cycles, and the daily average is what drains a battery.

Step 2: Work out the usable capacity

A power station's capacity is listed in watt-hours (Wh). When it powers AC appliances, some energy is lost converting battery DC power to 120 V AC. We use 85% of rated capacity as the usable figure for AC loads, the same factor we use across our site. Your result can be a little better or worse depending on the model and load.

For a 1,024 Wh station such as the Anker SOLIX C1000 Gen 2: 1,024 × 0.85 ≈ 870 Wh usable.

Step 3: Divide, and check the result

Runtime (hours) = usable Wh ÷ average watts

With our 72 W example fridge: 1,024 Wh × 85% ÷ 72 W ≈ 12 hours. If your fridge is older or bigger, use a more conservative figure. At a 150 W average: 1,024 Wh × 85% ÷ 150 W ≈ 5.8 hours.

One more check: the power station's inverter must handle the compressor's startup surge, which is briefly higher than its running watts. Check your fridge's manual or nameplate, and choose a station whose surge rating comfortably exceeds it. Every station in the table below has a continuous rating far above a fridge's running draw.

Runtime table: popular power stations

Estimated hours for a fridge averaging 72 W (an efficient modern model) and 150 W (older or larger fridges). Capacities are the manufacturers' published figures.

Estimates use capacity × 85% ÷ average watts. Real runtime depends on room temperature, how often the door opens and how full the fridge is.

How to make the battery last longer

• Keep the door shut. Ready.gov notes that a refrigerator keeps food cold for about four hours without power, and a full freezer holds its temperature for about 48 hours. Every opening shortens that.
• Run it in cycles if the outage is long. Because a closed fridge stays cold for hours, you can power it for a few hours, unplug it for a few hours, and stretch a battery much further. Use a fridge thermometer and keep food at 40°F or below. Ready.gov advises discarding perishable food that has been above 40°F for two hours or more.
• Recharge with solar during the day. A station that accepts high solar input can top up while it powers the fridge. Check each model's maximum solar input in our reviews.
• Turn off what you don't need. Ice makers and door heaters (anti-sweat settings) add load.

Mini fridges, chest freezers and 12V fridges

The same three steps work for any appliance that cycles on and off. Compact refrigerators and freezers sold in the US also carry EnergyGuide labels, so start with the yearly kWh figure and convert it to average watts.

Portable 12V compressor fridges, popular for camping and RVs, don't have EnergyGuide labels. Look for the average consumption on the manufacturer's spec sheet instead; it's usually far lower than a household fridge. If yours averages 35 W, a 1,024 Wh station would run it for about 25 hours on AC power, and a little longer from the 12V outlet because you skip the inverter losses.

A chest freezer is often the easiest appliance to keep going: it's well insulated and holds cold for a long time when the lid stays shut, which makes the cycling trick below especially effective.

Common mistakes when sizing a power station for a fridge

• Using the nameplate wattage. It's the maximum draw, not the average. It can make a fridge look several times hungrier than it really is.
• Forgetting inverter losses. Dividing full capacity by watts gives an optimistic answer. Use 85% of capacity for AC appliances.
• Ignoring the startup surge. A small station may have enough energy but not enough surge capacity to start the compressor.
• Testing in the wrong conditions. A fridge works harder in a hot kitchen or when it's opened often, so leave a margin, especially in summer outages.
• Counting on ideal solar numbers. Brands quote solar recharge times in strong sun. Clouds, short winter days and panel angle all slow it down.

What size power station do you need for a fridge?

• Overnight (about 12 hours): a 1 kWh-class station such as the Anker SOLIX C1000 Gen 2 or the BLUETTI AC180 covers an efficient fridge.
• A full day or more: look at 2 kWh and up, such as the EcoFlow DELTA 3 Max (2,048 Wh) or the PECRON F3000LFP (3,072 Wh).
• Multi-day outages: pair a large station with solar panels, or choose an expandable system such as the EcoFlow DELTA Pro 3.

Want to test other appliances? Our comparator estimates runtime for common devices on any station we list.