Free instant calculator

Power Station for an Air Conditioner

Air conditioners are one of the most demanding common loads people ask about — this page gives you the calculator plus a realistic, honest look at what to actually expect.

Wh

Select your devices

Total load: 1200 W

Kitchen & Food

Refrigeratorcycles on/off · ~3× surge at start W
Mini Fridge / Coolercycles on/off · ~3× surge at start W
Microwave W
Coffee Makercycles on/off W
Electric Kettle W

Climate & Comfort

Fan (standing/box) W
Portable Air Conditionercycles on/off · ~3× surge at start W
Electric Blanketcycles on/off W

Entertainment & Gaming

TV (LED, 40-55")varies with use W
PS5 / Xbox Series Xvaries with use W

Electronics & Office

Laptopvaries with use W
Gaming PC (desktop)varies with use W
Wi-Fi Router / Modem W
Phone Charger W
Hair Dryer W

Medical

CPAP Machine W

Lighting

Light Bulb (LED) W
LED Strip / Camping Lights W

Laundry

Washing Machinevaries with use · ~2× surge at start W
Dishwashervaries with use · ~2× surge at start W

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Estimated runtime

Enter your power station’s capacity in Wh to see a runtime estimate.

Capacity0 Wh
Usable energy0 Wh
Total consumption1,200 W
Efficiency85%

This is an estimate. Real-world runtime can be lower than the theoretical figure due to inverter efficiency losses, fluctuating (not constant) device draw, ambient temperature, battery age/health, and other factors. Always check your power station’s official specifications before relying on it for critical use.

A reality check before you calculate

A small portable air conditioner typically draws around 1200 W on average while its compressor is running — several times heavier than most other common household devices, which means even a large power station provides comparatively short runtime. Like a refrigerator, an AC's compressor cycles on and off rather than running constantly, so this 1200 W default is already an averaged running figure, not the nameplate/rated wattage (which is typically higher) or the instantaneous draw during an active cycle. See the glossary for what each of those terms means. Check your specific unit's nameplate and, ideally, a measured average, since window and portable AC units vary widely.

If your primary goal is just staying cool rather than running AC specifically, a fan (around 50 W) delivers dramatically more runtime from the same power station — worth comparing directly using the fan quick-calc button above.

The startup surge is the real challenge

Air conditioner compressors draw a substantial surge — commonly a few times their running wattage as a rough planning figure, though real surge varies significantly by unit and is not something we can state precisely without your specific model's spec sheet — for a moment when they start. This is frequently the actual limiting factor: a power station might have enough capacity to run an AC for a while, but not enough surge rating to start it in the first place. Always check your power station's rated surge/peak watts (not just its continuous watts) against your AC unit's actual startup requirements — printed on its nameplate or spec sheet — before relying on this combination.

Setting realistic expectations

At a 1200 W continuous load, even a large 3000 Wh power station provides only around 2 hours 7 minutes of runtime at 85% efficiency — enough to bridge a short, urgent window, but not a practical way to run AC through a full hot day or overnight. For sustained cooling needs, most people rely on grid power, a dedicated generator sized for AC startup surge, or a much larger fixed battery system rather than a portable power station.

FAQ

Frequently asked questions

Can a power station run a portable air conditioner all night?

Generally not from a single charge — AC's high continuous draw means even large power stations provide only a couple of hours of runtime. For overnight cooling, consider a fan as a lower-power alternative, or plan around grid power/a generator for sustained AC use.

Why won't my power station start my air conditioner even though it has enough capacity?

This is almost always a surge (peak wattage), not a capacity, problem — the compressor's brief startup draw can exceed your power station's surge rating even if its continuous rating and total Wh capacity look sufficient on paper. Check your power station's specified surge wattage against your AC's startup requirements.

What size power station would I need to run AC for several hours?

Use the calculator above with your AC's actual wattage and desired hours in "What capacity do I need?" mode — but expect the resulting number to be large (likely multiple thousand Wh) given how power-hungry AC units are, and remember this only addresses capacity, not whether the unit can handle the startup surge.

Is a fan a reasonable alternative to AC for battery-powered cooling?

For many situations, yes — a fan draws roughly 20–40x less power than a portable AC unit, delivering dramatically longer runtime from the same power station, even though it cools differently (air movement rather than active refrigeration). Worth considering when battery capacity is the limiting factor.