How Long Will a 200Wh Power Station Last?

A 200 Wh power station has about 170 Wh of usable energy. That runs a refrigerator for roughly 2.8 h, a laptop for 2.8 h and a CPAP for 4.3 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
1.7 hours
1 h 42 min
In days
0.07 days
Usable energy
170 Wh
Total capacity
200 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 200 Wh power station, by device

At 85% usable capacity (170 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 W18.9 h
Phone charger15 W11.3 h
Wi-Fi router and modem15 W11.3 h
CPAP machine40 W4.3 h
Mini fridge (average)30 W5.7 h
Full-size refrigerator (average)60 W2.8 h
Laptop60 W2.8 h
Box fan50 W3.4 h
LED TV100 W1.7 h
Desktop computer200 W51 min
Microwave1,000 W10 min
Coffee maker1,000 W10 min
Space heater1,500 W7 min

Is 200 Wh enough?

This is a small unit for phones, laptops, lights and a CPAP for a night. It will not keep a refrigerator going for long. 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 200Wh power station run a refrigerator?

A full-size fridge averages about 60 W over a day, so 200 Wh (170 Wh usable) runs it for roughly 2.8 h. Older or larger fridges use more, so the time can be shorter.

How many times will a 200Wh power station charge a phone?

About 11 full charges, at about 15 Wh of battery per phone, before losses in charging.

How long will a 200Wh power station run a CPAP?

About 4.3 h at 40 W, which is 0.5 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.