How long will a portable power station run a space heater?

Short answer: not for long, and we wouldn’t plan on it. A space heater on high is about the hungriest thing you can plug into a power station. A Vornado AVH2 on high empties an EcoFlow DELTA 2 in about 0.6 hours, and on low you get 1.2 hours. Even the EcoFlow DELTA Pro, the biggest station in our data, lasts 4.0 hours on low. That’s an evening at best. The small stations can’t run these heaters at all, not even on low.

Which stations can run one

All five Vornado heaters on this page have the same two ratings in their owner’s guides, one for high and one for low. So a single check covers all of them.

Look closely at the Jackery Explorer 1000 v2 rows. It passes on high, but only because its inverter limit is exactly the heater’s high rating. That leaves no headroom at all, and we’d use low on that station.

Vornado doesn’t publish a startup figure, so the passing rows say “surge unverified”. What empties the battery is the steady draw in the tables.

Where these numbers come from

The heat settings in the owner’s guides are rated values. A heater’s thermostat switches the element off once the room is warm and back on when it cools, so over a few hours the average draw can be lower than the rating. How much lower depends on the room. In a cold, drafty space the heater will be on most of the time, and you’ll get close to the table. In a small, well-insulated room you’ll do better, but we can’t tell you by how much.

Everything here is calculated, not measured. We take the station’s rated capacity, apply an AC efficiency factor (our assumption, printed under the table) and divide by the rated draw. We haven’t run any of these heaters on these stations.

Runtime by station

One table covers all five heaters: the Vornado AVH2, Vornado AVH4, Vornado VMH300, Vornado VMH500 and Vornado VTH. Their published ratings match, so their rows would be identical. We left out the small stations, since they failed the check above. The runtime calculator has the rest of the stations in our data.

So what should you do?

If you need heat through a power cut, a power station only gives you a short burst of it. Use low rather than high, heat one small room with the door shut, and switch the heater off when you’re warm enough. That roughly doubles your hours over high, and it’s still not a night.

For staying warm overnight in a tent or a van, heat yourself instead of the air: a sleeping bag rated for the temperature, a warm layer, a hat. Don’t swap in a mains electric blanket either. The one brand in our data says not to use its blankets with inverters, which is what a power station’s AC outlet is. We cover that on our electric blanket page.