Power Station / UPS Runtime Calculator
Enter your power station's capacity in Wh and what you'll plug in, and get the hours it lasts, plus ready answers for a phone, a refrigerator and a CPAP.
Power station runtime
E07Scenario A
Estimated runtime
At a 100 W load, after about 15% inverter loss.
- Runtime
- 8.7 h
- Phone charges (~15 Wh)
- 58
- Refrigerator (60 W average)
- 15 h
- CPAP (40 W)
- 22 h
Estimate. Formula and sources are under “How it works”. Change any input; the result updates as you type.
Formula
How it works
- Usable energy = capacity in Wh × 0.85 (about 15% is lost in the inverter that turns battery power into household AC)
- Runtime in hours = usable energy ÷ load in watts
- Ready answers (same capacity): phone charges at about 15 Wh each · hours for a refrigerator averaging 60 W · hours for a CPAP at 40 W
Sources: capacities from the manufacturers' published specs (EcoFlow Delta 2: 1,024 Wh; Jackery Explorer 1000: 1,070 Wh; Anker C1000: 1,056 Wh). 85% inverter efficiency is a typical figure for this class of unit.
Worked example
A worked example
A 2,048 Wh power station carrying a 600 W load runs for about 2.9 hours. The same unit could recharge a phone about 116 times, keep a refrigerator averaging 60 W going for about 29 hours, or run a 40 W CPAP for about 44 hours.
Questions
FAQ
How long will a Jackery run a refrigerator?
A Jackery 1000 (1,070 Wh) has about 910 Wh usable after the inverter. A refrigerator averaging 60 W over the day runs about 15 hours on it. The fridge's compressor needs more when it starts, so check that the power station's surge rating covers it.
Can a power station run a CPAP all night?
Yes, for most. At 40 W, a 1,024 Wh unit lasts about 22 hours; even a 300 Wh unit lasts about 6 hours. If you use a heated humidifier, enter the watts with it on: it adds to the draw.
What's the difference between Wh and Ah?
Wh (watt-hours) is energy: what the calculator needs. Ah (amp-hours) is charge, and only becomes energy once you multiply by the battery's voltage: Wh = Ah × volts. A 100 Ah battery at 12.8 V holds 1,280 Wh.
Why do I get fewer hours than the Wh suggests?
The inverter that makes household AC power loses energy as heat, about 15% in this calculator. Devices that charge from the USB or 12 V ports skip the inverter and get a little more.
Power station or generator?
A power station is silent, runs indoors and needs no fuel, but it stores a day or less for most loads. A generator runs as long as it has fuel. For an apartment or a CPAP, a power station is usually enough; for a whole house, compare the generator pages.
Related