Roughly a day per 2kWh for a typical full-size fridge, and about twice that for an efficient one. The exact figure depends on your fridge's real average draw, which is much lower than its running watts because the compressor cycles on and off.
Runtime by station
We plan on 85% of rated capacity being usable: hours = Wh x 0.85 ÷ watts. The 100W column is the cautious case of a fridge running non-stop. The 50W column is closer to a modern full-size fridge averaged over a day.
| Station | Capacity | Fridge at 100W, always on | Fridge averaging 50W |
|---|---|---|---|
| C1000 Gen 2 | 1,024Wh | about 9 h | about 17 h |
| S2000 | 2,010Wh | about 17 h | about 34 h |
| C2000 Gen 2 | 2,048Wh | about 17 h | about 35 h |
| F3000 | 3,072Wh | about 26 h | about 52 h |
| F3800 Plus | 3,840Wh | about 33 h | about 65 h |
| S5000 | 5,024Wh | about 43 h | about 85 h |
Anker's own claims sit close to the 50W column: up to 35 hours of fridge backup for the S2000 (tested on a large 24.7 cu ft fridge), up to 32 hours on a dual-door fridge for the C2000 Gen 2, and 42 hours on a 190W fridge for the F3000. That last one shows why the running wattage misleads: a fridge rated 190W runs far longer than 3,072Wh ÷ 190W would suggest, because the compressor is off much of the time.
Work out your own fridge
- Find the yearly figure on the yellow EnergyGuide label, in kWh per year.
- Divide by 365 to get watt-hours per day, then by 24 for the average watts. A fridge rated 400 kWh a year uses about 1,100Wh a day, an average of about 46W.
- Divide the station's usable watt-hours (capacity x 0.85) by that average. An F3000 gives about 2,611Wh usable, so about 57 hours on that fridge.
Real use runs higher than the label in a hot garage or RV, or when the door is opened often. Leave a margin.
Things that change the answer
- Start-up surge. A compressor needs a short burst of several times its running watts to start. Every station in the table has at least 1,500W rated output, so a household fridge starts without trouble.
- RV absorption fridges. On electric mode they heat an element continuously and use far more than a compressor fridge, so a station drains quickly. On propane they need only a little 12V power for the controls. Check your fridge's manual for its electric draw.
- The station's own idle draw. Anker lists 9W for the C2000 Gen 2 and 6W active idle for the S2000. Over a long outage that adds up, so turn off outputs you are not using.
- Recharging. Solar during the day can keep a fridge going indefinitely. One PS400 on a good, sunny day can make about as much as a modern fridge uses; see PS100, PS200 or PS400 sizing.
Which station for fridge backup
For one fridge through a typical outage of a day or two, a 2kWh station such as the S2000 or C2000 Gen 2 is enough. For a fridge plus a freezer, or outages that run several days, look at the F3000 with a BP3000, or a home system like the E10. Browse all Anker SOLIX portable power stations.