- 450W
- while running, 1,200W to start
- 7,560Wh
- used over a full day
- 12 of 15
- models we track can run it
- Best for daily solar useBluetti Elite 200 V25.6 hr$899Check price
- Budget pick for short outagesBluetti Elite 100 V22.8 hr$489Check price
- Best for a full nightAnker Solix F380010.4 hr$1,979.99Check price
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Runtime for every model
| Model | Runtime | Capacity | Output | Weight | Price | Per Wh |
|---|---|---|---|---|---|---|
| EcoFlow River 3 | Can't run it | 245Wh | 300W | 7.8 lb | $239 | $0.98 |
| Jackery Explorer 300 v2 | Can't run it | 288Wh | 300W | 8.2 lb | $299 | $1.04 |
| Anker Solix C300 | Can't run it | 288Wh | 300W | 9.1 lb | $249 | $0.86 |
| EcoFlow River 3 Plus | 0.8 hr | 286Wh | 600W | 10.4 lb | $299 | $1.05 |
| Bluetti AC70 | 2.1 hr | 768Wh | 1,000W | 22.5 lb | $359 | $0.47 |
| EcoFlow Delta 3 Plus | 2.8 hr | 1,024Wh | 1,800W | 27.6 lb | $669 | $0.65 |
| Jackery Explorer 1000 v2 | 2.9 hr | 1,070Wh | 1,500W | 23.8 lb | $499 | $0.47 |
| Anker Solix C1000 Gen 2 | 2.8 hr | 1,024Wh | 2,000W | 24.9 lb | $499.99 | $0.49 |
| Bluetti Elite 100 V2 | 2.8 hr | 1,024Wh | 1,800W | 25 lb | $489 | $0.48 |
| EcoFlow Delta 3 Max | 5.5 hr | 2,048Wh | 2,400W | 44.8 lb | $879 | $0.43 |
| Jackery Explorer 2000 v2 | 5.5 hr | 2,042Wh | 2,200W | 39.5 lb | $899 | $0.44 |
| Anker Solix C2000 Gen 2 | 5.5 hr | 2,048Wh | 2,400W | 41.7 lb | $899.99 | $0.44 |
| Bluetti Elite 200 V2 | 5.6 hr | 2,073Wh | 2,600W | 53.4 lb | $899 | $0.43 |
| EcoFlow Delta Pro 3 | 11.1 hr | 4,096Wh | 4,000W | 113.5 lb | $2,799 | $0.68 |
| Anker Solix F3800 | 10.4 hr | 3,840Wh | 6,000W | 132.3 lb | $1,979.99 | $0.52 |
Shaded rows are our picks. Assumed load: A 5,000 BTU window unit pulling 450W with the compressor on, running 70% of the time on a hot day, with a 1,200W startup surge.
What a small window unit draws
An air conditioner’s size is given in BTU, a measure of how much heat it can move out of a room in an hour. A 5,000 BTU unit is the smallest common size and suits one small bedroom. It pulls about 450W while the compressor is on. The compressor is the pump inside that does the cooling work.
On a hot day the compressor runs about 70% of the time, so the average is about 315W. That is roughly five times what a full-size fridge averages.
It adds up quickly. A 1,000Wh unit lists 2.8 hours, a 2,000Wh unit 5.5, and the two largest units we track 10.4 and 11.1. A watt-hour (Wh) is a unit of energy: one watt used for one hour.
Starting the compressor
A compressor needs a short burst of extra power to get going, about 1,200W for this size. That burst is called startup surge, and it has to fit under the power station’s surge rating.
The three 300W units cannot run the air conditioner at all. The EcoFlow River 3 Plus is exactly at its 1,200W surge limit, which leaves no margin, and it would last only 0.8 hours anyway. Every pick here can supply at least double that.
Inverter units and bigger units
Some newer window units are inverter types. Their compressor can slow down instead of switching fully on and off. They start gently and use less power on average, so the same battery lasts longer. If you are buying an air conditioner with backup in mind, that is the type to look for.
Bigger units go the other way. An 8,000 BTU unit or larger draws more, and every runtime here drops to match.
Check the nameplate on yours. It lists amps. Multiply the amps by 120 volts to get watts, then scale our numbers. If yours pulls 600W and not 450W, 5.5 hours becomes about 4.1.
Getting more hours from the same battery
Cool one small room and shut the door. Close the curtains on the sunny side.
Pre-cool if you can. When you know an outage is coming, run the air conditioner on grid power first and get the room cold. The compressor then has less work to do once you are on battery.
Set the temperature a few degrees higher. The compressor rests more, and the rest is where the hours come from. If it runs 50% of the time and not 70%, 5.5 hours becomes about 7.7.
Solar for the daytime
Hot days are usually sunny days, so solar panels and air conditioning suit each other. A power station’s solar input rating is the most panel power it can accept. If the panels feed in more than the 315W average, the station can run the air conditioner and still gain charge.
Panels rarely deliver their full rated output, so the input rating needs slack. The Jackery Explorer 2000 v2 accepts 400W, which leaves little. The Anker C2000 Gen 2 accepts 800W, both Bluetti picks accept 1,000W, and the Anker F3800 accepts 2,400W.
When heat is a health risk
If anyone in the home is at risk in high heat, such as an older person or an infant, a few hours of battery is not a plan. Know where the nearest cooled public place is before the outage starts.
The picks in detail
Anker Solix C2000 Gen 2
- 5.5 hr
- 5,000 BTU window air conditioner
- $899.99
- $0.44 per Wh
- 41.7 lb
- Weight
It lists 5.5 hours on a 5,000 BTU unit, and it is the only 2,000Wh unit here that can grow. One expansion battery takes it to 4,096Wh, which would roughly double the hours. Its 4,000W surge rating is more than three times the compressor's 1,200W start. It accepts up to 800W of solar, well above the air conditioner's 315W average. At $899.99 it costs $0.44 per watt-hour.
What fits
- 5.5 hours on a 5,000 BTU unit
- Expandable to 4,096Wh with one expansion battery
- 800W solar input
What does not
- 5.5 hours will not last a full night
- 41.7 lb to move to the room you are cooling
Anker's list price is $1,499.99. Anker lists a 9W idle draw, which is low for this size.
Bluetti Elite 200 V2
- 5.6 hr
- 5,000 BTU window air conditioner
- $899
- $0.43 per Wh
- 53.4 lb
- Weight
If you plan to run the air conditioner from solar panels through a long summer outage, the battery is drained and refilled every day. This unit is rated for 6,000 of those cycles, the most of any unit here, and accepts up to 1,000W of solar. It lists 5.6 hours for $899, a few minutes more than its rivals. The costs are its 53.4 lb and a gap in the specs. Bluetti lists no surge rating for it, so our math uses its 2,600W rated output.
What fits
- 6,000-cycle rating, the highest here
- 1,000W solar input
- 5.6 hours on a 5,000 BTU unit
What does not
- 53.4 lb, the heaviest 2,000Wh unit
- No surge rating listed by Bluetti
Bluetti's list price is $1,099.
Bluetti Elite 100 V2
- 2.8 hr
- 5,000 BTU window air conditioner
- $489
- $0.48 per Wh
- 25 lb
- Weight
This unit lists 2.8 hours of cooling, enough to take the edge off a late-afternoon outage and not much more. At $489 it is the lowest-priced 1,000Wh unit, and it suits an air conditioner best of the four because it accepts 1,000W of solar, matched only by the EcoFlow Delta 3 Plus at $180 more. Its 3,600W surge rating is three times the compressor's 1,200W start. $489 works out to $0.48 per watt-hour.
What fits
- 1,000W solar input for $489
- 3,600W surge, three times the compressor's start
What does not
- Only 2.8 hours on a hot day
- Cannot be expanded with extra batteries
Sale prices under $400 have appeared.
Anker Solix F3800
- 10.4 hr
- 5,000 BTU window air conditioner
- $1,979.99
- $0.52 per Wh
- 132.3 lb
- Weight
This is the cheapest unit in the table that gets a small window unit through a night. It lists 10.4 hours for $1,979.99, against 11.1 hours for the EcoFlow Delta Pro 3 at $2,799. Its 2,400W solar input is more than seven times the air conditioner's 315W average, so a large array could run the unit and refill the battery in the same day.
What fits
- 10.4 hours on a 5,000 BTU unit
- 2,400W solar input
What does not
- 132.3 lb
- $1,979.99 to cool one small room overnight
Anker's list price is $2,199.99. A newer F3800 Plus is sold alongside it for more.
Verdict
Buy the Anker Solix C2000 Gen 2 if you want an afternoon or half a night of cooling now and the option to double it later. Choose the Bluetti Elite 200 V2 if you will pair it with solar panels and cycle it daily through long summer outages. The Bluetti Elite 100 V2 is the budget choice, as long as 2.8 hours is enough. The Anker Solix F3800 is the lowest-cost way to cover a whole night. If your window unit is 8,000 BTU or larger, expect less than every figure here.
How these numbers were worked out. Runtime = battery capacity × efficiency ÷ average watts. We use 85% efficiency for AC outlets and 90% for DC and USB ports, because some energy is lost as heat on the way out. A model is marked "can't run it" when the device needs more watts than the outlet gives, or a bigger startup surge than the unit is rated for. Your own device may draw more or less than our assumed load, so treat these as estimates. Prices were checked on 2026-10-04 and change often. Full method
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