Can a portable power station run an air conditioner?

Yes, but only a small unit, and not for long. A 1,000 Wh class station with at least 1800 W of rated output, like the EcoFlow DELTA 3 Plus, runs an 8000 to 10000 BTU window air conditioner for about 50 minutes to 1.2 hours with the compressor running nonstop. Bigger units and their compressor start need a 3,000 Wh class station with a surge rating of 7200 W or more to be safe.

How many watts does a window air conditioner use?

Small window units draw about 720 to 1020 W while cooling, by their makers' specs. The Frigidaire FHWC083TC1 (8000 BTU) is rated at 8.4 A at 115 V, about 720 W. The GE ASV10AB (10000 BTU) lists 1020 W.

Generator sizing charts use bigger numbers for bigger units: Champion lists a 13000 BTU window unit at 1800 W running, and Generac lists a 12000 BTU unit at 3250 W. Those chart figures are deliberately cautious, so read your own unit's label.

The start matters as much as the running draw. A compressor pulls a short burst each time it starts, and it starts again every time the thermostat calls for cooling. Champion lists 2800 W starting for a 13000 BTU unit; Generac lists 3950 W of additional starting watts on top of 3250 W running for a 12000 BTU unit, a 7200 W peak. Makers of the smaller units in our data do not publish a starting figure.

How do you work out the runtime?

Runtime (hours) = battery Wh x inverter efficiency / load W.

Take the EcoFlow DELTA 3 Plus. Its battery is 1024 Wh. EcoFlow does not publish an inverter efficiency, so we use 0.85, which leaves about 870 Wh at the outlet.

• 8000 BTU unit at 720 W: 870 / 720 = about 1.21 hours.
• 10000 BTU unit at 1020 W: 870 / 1020 = about 0.85 hours, or 51 minutes.

Those times assume the compressor never stops. On a mild day it cycles off once the room is cool and the battery lasts longer; on a hot afternoon it may run almost without a break. We do not have a sourced average draw for window units, so the nonstop figure is the honest planning number.

How long do bigger power stations run an air conditioner?

Roughly 1.7 to 2.4 hours on a 2048 Wh station and 3.2 to 4.5 hours on a 3,840 Wh station, for the 720 to 1020 W units:

Each row uses the maker's published battery, output and surge and the 0.85 efficiency assumption. For example, the Anker SOLIX F3800: 3840 x 0.85 = 3264 Wh, and 3264 / 720 = about 4.5 hours.

Can every power station start an air conditioner?

No. The station has to clear two limits:

• Rated output. The unit's running watts must fit under the station's rated AC output. A 600 W station like the EcoFlow RIVER 3 Plus is under even the 720 W Frigidaire, so it cannot run it at all.
• Starting surge. The compressor's start must fit under the station's surge rating. Against Champion's 2800 W figure, the Jackery Explorer 1000 v2 (3000 W surge) and the EcoFlow DELTA 3 Plus (3600 W) clear it, while the BLUETTI AC180 (2700 W) does not. Against Generac's 7200 W figure for a 12000 BTU unit, only the 3,000 Wh class and up clear it: the EcoFlow DELTA 3 Ultra (7200 W), the EcoFlow DELTA Pro 3 (8000 W) and the Anker SOLIX F3800 (9000 W) among them.

Units with a variable-speed (inverter) compressor are designed to ramp up instead of starting at full load, which is easier on a station, but their makers rarely publish a starting figure either. Leave headroom and test the unit on the station before you need it.

What size power station runs an air conditioner all night?

On one charge, almost none of the portable stations in our data. Eight hours at 720 W is 5760 Wh of load, and at 0.85 efficiency that needs about 6,800 Wh of battery, more than any base unit here; the largest, the Jackery Explorer 5000 Plus, has 5040 Wh.

Expandable stations get there with add-on batteries. The Anker SOLIX F3800 expands to 26880 Wh: 26880 x 0.85 / 720 = about 31.7 hours for the 8000 BTU unit, or about 22.4 hours at 1020 W. The Jackery Explorer 5000 Plus expands to 30000 Wh.

How can you make the battery last longer?

Pick the smallest unit that cools the room, close the door to that room, set the thermostat a few degrees higher and keep other big loads off the station. Running a fan instead of the AC for part of the night stretches it most, since a fan draws a small fraction of a compressor's watts (fan figures with sources).

Use the runtime calculator with your unit's label watts, and see which stations can run a window AC for every station in our data. For recharging, see how long it takes to charge a power station with solar. For backing up more than one room, see can a solar generator run a house.