You need about 3,422 Wh — and 12 units fit. The smallest sufficient is the Mango Power Power E; we never push more capacity than your load can use. Surge to clear: 1,800 W.
The math
Running watts (everything on at once) = 1,100 W
Surge watts (worst single startup + the rest running) = 1,800 W
Average draw (cyclic loads counted by their duty cycle) = 770 W
Watt-hours = 770 W × 4.0 h ÷ 90% usable reserve = 3,422 Wh
1
Mango Power Power Esmallest that fits
3,506 Wh3,000 W cont · 4,800 W surgeexpandable~4.1 h on this load$$$
First Mango Power entry — a 3.5 kWh, 3,000 W home-backup unit on CATL LFP cells rated 6,000+ cycles, expandable to 14 kWh with add-on batteries.
LiFePO4 (CATL) · 0-80% in 60 min AC (30A fast-charge cable); full in ~1.5 h · 100 lb
3,840 Wh2,600 W cont · 3,900 W surge~4.5 h on this load$$$
Bluetti's own billed as the lightest 3.8 kWh station on the market — a non-expandable, sealed unit undercutting the EcoFlow DELTA Pro and Anker SOLIX F2600 on price/capacity; part of the new Elite series alongside the existing elite-300/elite-100-v2/elite-200-v2.
LiFePO4 · AC+solar combined 0-80% in 70 min (2,800 W); AC-only full in 2.5 h; solar max 1,000 W · 86 lb
3,840 Wh6,000 W cont · 12,000 W surgeexpandable~4.5 h on this load$$$
The newer-generation F3800 — same 3,840 Wh and 6,000 W continuous rating, but double the solar input (3,200 W) and adds 240V gas-generator bypass charging for extended outages.
LiFePO4 · ~1.5 h with 240V generator input; under 3 h AC; up to 3,200W dual-MPPT solar · 137 lb
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Can a specific unit run a window ac (12,000 btu)?
42 of the units we track deliver enough watts to run a window ac (12,000 btu). Check a specific one for the runtime and the full verdict:
What size power station do I need to run a window ac (12,000 btu)?
A window ac (12,000 btu) draws about 1,100 W running, with a startup surge near 1,800 W. So you want a unit with at least 1,100 W continuous output and 1,800 W+ surge. For 4.0 h of runtime that's roughly 3,422 Wh of capacity — the Mango Power Power E is the smallest unit that clears all of it.
How many watts does a window ac (12,000 btu) use?
About 1,100 W while running, spiking to roughly 1,800 W on startup. It only draws power about 70% of the time, so over an outage its energy use is well below 1,100 W × the hours — which is why a modest battery lasts longer than you'd expect.
Sources: Window AC (12,000 BTU) wattage — Standard appliance-wattage / generator-sizing charts (representative values; verify your nameplate); 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.