It’s a common plan: if the power goes out in winter, plug a space heater into the power station. Unfortunately, the numbers don’t work out.
The math
A standard space heater uses 1,500 W on high and about 750 W on low. Most power stations with 1,800 W or more of output can technically run one. The problem is how fast the battery empties:
| Power station | 1,500 W (high) | 750 W (low) |
|---|---|---|
| 1,000 Wh | ~35 min | ~1.1 h |
| 2,000 Wh | ~1.1 h | ~2.3 h |
| 3,600 Wh | ~2 h | ~4 h |
Runtime = Wh × 0.85 ÷ watts. Heating is about the most energy-hungry thing you can do with electricity. An electric heater turns every watt-hour into heat, but it needs an awful lot of them.
Warm yourself, not the room
These use a fraction of the power:
| Device | Power | Runtime on 1,000 Wh |
|---|---|---|
| Electric blanket | 50–100 W | 8.5–17 h |
| Heated mattress pad | 50–90 W | 9.5–17 h |
| Heated vest or jacket (USB) | 10–20 W | 40+ h |
| Heating pad | 30–60 W | 14–28 h |
An electric blanket on a 1,000 Wh unit can get you through a cold night. A space heater can’t.
Or keep the furnace running
If you have a gas or propane furnace, it only needs electricity for the blower, the ignition and the controls, usually 300–800 W. A power station of 2,000 Wh or more, or a generator, can often keep it going for hours and heat the whole house on gas. It does need a safe connection, normally a transfer switch or a cord-and-plug conversion for the furnace done by a licensed electrician. Our generator sizing guide covers other options.
Low-power ways to stay warm
- Pick one room, ideally small, on an inside wall and on the sunny side, and close it off.
- Cover the windows with blankets or heavy curtains at night, and open them on sunny days.
- Block drafts under doors with towels.
- Layer up: thermal base layers, hats and wool socks.
- Use sleeping bags rated for low temperatures.
- Eat and drink something warm. A camp stove (used outside) or a thermos of hot water helps.
Pipes
If the house is going to drop below freezing for a while, protect the plumbing: let the faucets drip, open the cabinet doors under sinks, and know where the main water shutoff is.
The takeaway
A power station can run a space heater, but only for minutes to a couple of hours. Use the battery for electric blankets, the furnace blower and the essentials, and plan other heat sources safely. Our winter power outage guide has the full plan.