What size power station do I need to run a Window AC (12,000 BTU)?

To run a Window AC (12,000 BTU) (about 1100 running watts) for 5 hours, plan on a station with at least 7200 watt-hours of capacity and 1100W continuous / 3000W surge output. Adjust for your real runtime.

How long will a power station run a Window AC (12,000 BTU)?

A Expandable home backup (≈6,000Wh+) station (6000Wh) runs a Window AC (12,000 BTU) for roughly ~4.2 h on a full charge.

SizingPlate

Power stations › Window AC (12,000 BTU)

What size power station to run a Window AC (12,000 BTU)?

Typical draw: 1100W running / 3000W starting. Sized below for a 5-hour run — drag the slider for your real runtime. Large room unit; needs a mid-size generator on its own.

POWER PLATE1 LOAD · 5 H RUNTIME

Continuous draw

1,100 W

Startup surge

3,000 W

Energy for 5 h

6,471 Wh

Buy at least

7,200 Wh

Look for ≥7,200Wh capacity, ~1,100W continuous / 3,000W surge or better.

Right size: Expandable home backup (≈6,000Wh+) · 5,000W

Typical price $3,500-6,000+ · e.g. EcoFlow Delta Pro Ultra, Bluetti AC500 + B300S (stackable)

Backing up whole circuits through a transfer switch; add battery modules for days of autonomy, especially with solar. A home-backup system, not a grab-and-go unit. For 240V loads or true whole-home coverage, compare against a standby generator.

Runs this load ~4.2 h on a full charge.

See current prices on Amazon

A Window AC (12,000 BTU) is a heavy load for battery power. Consider solar recharge, a shorter runtime, or a fuel generator.

Comparing against fuel? See what size generator runs a Window AC (12,000 BTU).

Adjust your loadout and runtime

Real setups aren't one appliance. Add loads and set your runtime below — your Window AC (12,000 BTU) is pre-checked.

POWER PLATE1 LOAD · 5 H RUNTIME

Continuous draw

1,100 W

Startup surge

3,000 W

Energy for 5 h

6,471 Wh

Buy at least

7,200 Wh

Look for ≥7,200Wh capacity, ~1,100W continuous / 3,000W surge or better.

Capacity includes inverter loss (~15%) and a usable-charge margin, so the station isn't run flat. A solar panel or vehicle charge extends runtime past this number.

How long do you need to run it? 5 h

Kitchen Refrigerator (full-size) 300W run / 1500W start Mini fridge 90W run / 700W start Chest freezer 250W run / 1200W start Microwave (1000W) 1400W run Electric range (one burner) 1500W run Coffee maker (drip) 900W run Toaster 1100W run Electric kettle 1400W run Dishwasher 1300W run / 1500W start Instant Pot / multicooker 1000W run

Heating & cooling Window AC (5,000 BTU) 500W run / 1500W start Window AC (8,000 BTU) 800W run / 2200W start Window AC (12,000 BTU) 1100W run / 3000W start Central AC (3-ton) 3500W run / 8500W start Space heater (1500W) 1500W run Furnace blower fan (gas furnace) 600W run / 1600W start Heat pump (2-ton) 2500W run / 6000W start Box fan 100W run / 150W start Ceiling fan 75W run / 100W start

Pumps & well Sump pump (1/3 HP) 800W run / 1500W start Sump pump (1/2 HP) 1050W run / 2200W start Well pump (1/2 HP) 1000W run / 2100W start Well pump (1 HP) 2000W run / 4000W start Sewage ejector pump (1/2 HP) 1000W run / 2200W start

Electronics TV (55" LED) 80W run Wi-Fi router + modem 15W run Laptop 65W run Desktop PC + monitor 350W run / 400W start Phone charger 10W run Starlink dish + router 75W run / 100W start

Medical & safety CPAP machine 60W run Oxygen concentrator 350W run / 600W start

Lighting LED lights (per room) 30W run

Laundry Washing machine 700W run / 1600W start Clothes dryer (electric) 5000W run / 6000W start Clothes dryer (gas) 700W run / 1800W start

Household Garage door opener (1/2 HP) 550W run / 1200W start Water heater (electric tank) 4500W run EV charging (Level 1, 120V) 1400W run

Tools & outdoor Circular saw 1400W run / 2300W start Air compressor (1 HP) 1500W run / 3000W start Welder (140A MIG) 3500W run / 4000W start

RV & camping RV air conditioner (13,500 BTU) 1300W run / 2900W start RV converter/charger 500W run Electric griddle 1200W run Slow cooker 250W run

Power stations that fit

Right size: Expandable home backup (≈6,000Wh+) · 5,000W

Typical price $3,500-6,000+ · e.g. EcoFlow Delta Pro Ultra, Bluetti AC500 + B300S (stackable)

Runs this load ~4.2 h on a full charge.

See current prices on Amazon

This load is heavier or longer than portable stations cover well. Add solar recharge, shorten the runtime, or look at a fuel generator for sustained high-wattage loads.

This site earns commissions from qualifying purchases made through links to Amazon and other retailers, at no extra cost to you. Wattage figures are typical estimates — actual draw varies by model. Always verify against your appliance's nameplate, and consult a licensed electrician for any panel or hardwired connections.