Runtime by power station size: Space heater (high, 1,500 W)
| Power station size | Typical runtime | Realistic range |
|---|---|---|
| 300 Wh | 10 min | 0.2–0.2 h |
| 500 Wh | 17 min | 0.3–0.4 h |
| 1,000 Wh | 34 min | 0.6–0.8 h |
| 1,500 Wh | 51 min | 0.8–1.2 h |
| 2,000 Wh | 1 h 8 min | 1.1–1.5 h |
| 3,000 Wh | 1 h 42 min | 1.7–2.3 h |
Runtime by power station size: Space heater (low, 750 W)
| Power station size | Typical runtime | Realistic range |
|---|---|---|
| 300 Wh | 20 min | 0.3–0.5 h |
| 500 Wh | 34 min | 0.5–0.8 h |
| 1,000 Wh | 1 h 8 min | 0.9–1.5 h |
| 1,500 Wh | 1 h 42 min | 1.4–2.3 h |
| 2,000 Wh | 2 h 16 min | 1.9–3.1 h |
| 3,000 Wh | 3 h 24 min | 2.8–4.6 h |
Heat is the most power-hungry thing in a home
Turning electricity into heat with a resistance element is simple but takes a lot of energy. One hour of a space heater on high uses as much energy as a refrigerator in a whole day. That's why power stations that comfortably cover a fridge, lights and Wi-Fi for a day get drained by a heater before dinner is over.
Check the output rating first
A space heater on high needs a station rated for at least 1,500 W continuous, ideally 1,800 W or more so it isn't running at its limit. Many 300–800 W stations will shut off the moment the heater switches on. Some brands offer a "power lifting" mode that runs heaters at reduced power on smaller stations. It works, but produces less heat in proportion.
Better ways to stay warm on battery
- Electric blanket: about 40–100 W on average, so 15–25× less than a heater. A 1,000 Wh station can run one for 8–20 hours. Heating the person instead of the room is the single biggest win.
- Heat one small room: close doors and pick the smallest room. A heater on low with a thermostat will cycle off once it warms.
- Gas furnace fan: if you have a gas furnace, its blower fan needs only a few hundred watts. It must be connected properly through a transfer switch or approved inlet installed by an electrician, never by backfeeding an outlet.
- Layers and insulation: sleeping bags, hats and heavy curtains cost no battery at all.
Compare an electric blanket with a heater by adding both in the runtime calculator.
Safety
- Plug the heater directly into the station. Don't use a thin extension cord or power strip.
- Keep the heater and the station away from bedding, curtains and each other's vents.
- Never run fuel-burning heaters or generators indoors. Carbon monoxide kills during outages every year.