Power station for a chest freezer: size and runtime
A chest freezer is a compressor that cycles on and off, so its daily use is far lower than the running watts suggest. The hard part is the start-up surge when the compressor kicks in.
Typical numbers
| Item | Typical running | Typical start-up surge | Per day |
|---|---|---|---|
| Chest freezer | 100 W | about 800 W | about 840 Wh |
Typical values, assuming the compressor runs about 35% of the time. Frost-free and older units use more; the EnergyGuide label gives yearly kWh.
Worked example
100 W × 24 h × 0.35 = 840 Wh a day. With 85% of rated capacity usable:
| Battery rating | Usable | Freezer runtime |
|---|---|---|
| 1,000 Wh | 850 Wh | about 24 hours |
| 2,000 Wh | 1,700 Wh | about 48 hours |
| 3,000 Wh | 2,550 Wh | about 73 hours |
Good to know
- USDA guidance: a full freezer stays safely frozen about 48 hours without power if the lid stays closed (about 24 hours if half full). You may only need to run it in part of the outage.
- Check the station's surge rating against about 800 W.
- Keep it full and the lid shut. Running the freezer a few hours at a time works well with a modest battery.
Open the calculator with a chest freezer filled in
Appliance figures are typical values, not measurements of your device: the label or a plug-in watt meter on yours wins. The sums assume 85% of a battery's rated capacity reaches your outlets (how the numbers work). We list no prices and have not hands-on tested any product.
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