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Scenarios › Power station for a window air conditioner

What size power station runs a window AC?

An 8,000 BTU window unit pulls about 715 W running with a ~1,250 W compressor surge. The compressor cycles, so capacity stretches further than you’d think. Here is the size to keep one room cool for an evening — and the step-up for a bigger unit or all night.

2,778 Whcapacity needed
715 Wrunning watts
1,250 Wsurge to clear
5.0 hruntime horizon

This load: Window AC (8,000 BTU). Want to tweak it? Open the full sizing tool and adjust the appliances and hours.

What size you need

You need about 2,778 Wh — and 17 units fit. The smallest sufficient is the Bluetti Elite 300; we never push more capacity than your load can use. Surge to clear: 1,250 W.
The math
Running watts (everything on at once) = 715 W
Surge watts (worst single startup + the rest running) = 1,250 W
Average draw (cyclic loads counted by their duty cycle) = 500 W
Watt-hours = 500 W × 5.0 h ÷ 90% usable reserve = 2,778 Wh
1
Bluetti Elite 300smallest that fits
3,014 Wh 2,400 W cont · 4,800 W surge ~5.4 h on this load $$$
Frost & Sullivan certified as the world's smallest 3 kWh class unit — a full 3,014 Wh / 2,400 W in a 58 lb body, no expansion path.
LiFePO4 · 0-100% in 78 min AC (0-80% in 70 min) · 58 lb
2
Jackery Explorer 3000 Pro
3,024 Wh 3,000 W cont · 6,000 W surge ~5.4 h on this load $$$
Three kilowatt-hours for multi-day outages and heavier loads, on wheels.
LiFePO4 · ~2.4 h AC; up to 1200 W solar · 64 lb
3
Goal Zero Yeti 3000X
3,032 Wh 2,000 W cont · 3,500 W surge expandable ~5.5 h on this load $$$
Three kWh on wheels for multi-day essentials backup.
NMC · AC/solar; integrates with home kit · 70 lb
4
Bluetti AC300 + B300
3,072 Wh 3,000 W cont · 6,000 W surge expandable ~5.5 h on this load $$$
A modular 3 kW system with a sub-20 ms UPS switch — toward whole-home with a transfer switch.
LiFePO4 · Modular; expandable to 12.3 kWh, 24/7 UPS · 116 lb
5
Anker SOLIX F3000
3,072 Wh 3,600 W cont · 7,200 W surge expandable ~5.5 h on this load $$$
A wheeled, landscape-form home-backup unit distinct from the tower-form F3800/F3800 Plus — slots between the SOLIX C-series and F3800, UL9540-certified, expandable to 24 kWh with BP3000 packs, two units pairable to 240V/7,200W via the Double Voltage Hub.
LiFePO4 · <3 h full via TT-30 (3,600 W AC input); dual-voltage 60V+165V solar up to 2,400 W, <2 h in good sun · 92 lb
6
Mango Power Power E
3,506 Wh 3,000 W cont · 4,800 W surge expandable ~6.3 h on this load $$$
First Mango Power entry — a 3.5 kWh, 3,000 W home-backup unit on CATL LFP cells rated 6,000+ cycles, expandable to 14 kWh with add-on batteries.
LiFePO4 (CATL) · 0-80% in 60 min AC (30A fast-charge cable); full in ~1.5 h · 100 lb
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The load, appliance by appliance

ApplianceRunningSurgeDuty
Window AC (8,000 BTU) 715 W 1,250 W 70% size on its own →
⚡ Informational only — a computed sizing estimate from published appliance-wattage charts and manufacturer station specs. It is not an electrical guarantee. For hardwired or whole-home backup, transfer switches, or any permanent install, consult a licensed electrician. Appliance wattages are representative chart values and vary by model; check your nameplates. Duty cycle (how much of the time a load actually draws) is how we keep the watt-hour estimate from overselling capacity.

Common questions

What size power station runs a window AC?

For Window AC (8,000 BTU) over 5.0 h, you need about 2,778 Wh of capacity, 715 W continuous output, and at least 1,250 W of surge. The smallest unit that clears all three is the Bluetti Elite 300; a step-up like the EcoFlow DELTA Pro 3 adds headroom for longer outages.

How many watt-hours does this load need?

About 2,778 Wh for 5.0 h — we take the duty-weighted average draw (500 W, since cyclic loads like fridges and pumps don't run constantly), multiply by the hours, and divide by a usable-capacity reserve. Running watts are 715 W; surge is 1,250 W.

Other scenarios

Power station for a home outage (fridge + CPAP + sump pump)
12 h
What size power station runs a CPAP all night?
8.0 h
What size power station / battery backup for a sump pump?
6.0 h
What size power station / solar generator for van life?
12 h
What size power station runs a refrigerator in an outage?
24 h
What size power station runs a 1500 W space heater?
3.0 h

Sources: appliance wattages — standard appliance/generator sizing charts; station specs — manufacturer published specifications (compiled 2026-10-05; approximate). Informational only — a computed sizing estimate from published appliance-wattage charts and manufacturer station specs. It is not an electrical guarantee. For hardwired or whole-home backup, transfer switches, or any permanent install, consult a licensed electrician.