How Long Will a 700Wh Power Station Last?

A 700 Wh power station has about 595 Wh of usable energy. That runs a refrigerator for roughly 9.9 h, a laptop for 9.9 h and a CPAP for 14.9 h. Enter your own device below.

Your project

Wh
%

About 85% for power stations (inverter losses), about 50% for lead-acid batteries, and 80 to 90% for lithium (LiFePO4) batteries.

W

The watts of the device. Check its label, or use a plug-in watt meter.

Results

Runtime
6.0 hours
5 h 57 min
In days
0.25 days
Usable energy
595 Wh
Total capacity
700 Wh
  • Runtime = usable watt-hours ÷ watts. Devices that cycle (refrigerators, pumps, heaters with thermostats) use less than their label rating on average, so real runtime is longer. Cold weather reduces battery capacity.

Runtime of a 700 Wh power station, by device

At 85% usable capacity (595 Wh), without recharging. Real runtime depends on the actual draw of your device, which you can measure with a plug-in watt meter.

DeviceTypical wattsRuntime
LED light bulb9 W66.1 h
Phone charger15 W39.7 h
Wi-Fi router and modem15 W39.7 h
CPAP machine40 W14.9 h
Mini fridge (average)30 W19.8 h
Full-size refrigerator (average)60 W9.9 h
Laptop60 W9.9 h
Box fan50 W11.9 h
LED TV100 W6.0 h
Desktop computer200 W3.0 h
Microwave1,000 W36 min
Coffee maker1,000 W36 min
Space heater1,500 W24 min

Is 700 Wh enough?

This size covers electronics, lights, a CPAP and a mini fridge for a day, but not much more. For a full plan, see the power station sizing guide, and the size calculator to work out your own daily energy.

Want to change anything else? The calculator above is the full Battery & Power Station Runtime Calculator: edit any number and the results update instantly.

Tools & materials for this project

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Frequently asked questions

How long will a 700Wh power station run a refrigerator?

A full-size fridge averages about 60 W over a day, so 700 Wh (595 Wh usable) runs it for roughly 9.9 h. Older or larger fridges use more, so the time can be shorter.

How many times will a 700Wh power station charge a phone?

About 40 full charges, at about 15 Wh of battery per phone, before losses in charging.

How long will a 700Wh power station run a CPAP?

About 14.9 h at 40 W, which is 1.9 nights of 8 hours. Using the humidifier raises the draw.

Related sizes and guides

Estimates only. Results assume standard materials and simple shapes. Supplier products vary, and the final call on quantity, structure and safety is yours. Check your local code and your supplier's guidance before ordering.