How long will a power station run a window AC?
Short answer: a few hours to most of a night for a small unit. A 2,000 Wh station runs an efficient 5,000 BTU window AC about 5 hours nonstop, and longer when the compressor cycles off. Bigger units drain it fast. Figures as of 2026-11-02.
Your unit's label (watts, or amps × 115 V) beats any number below.
Step 1: AC watts
Watts ≈ cooling BTU per hour ÷ CEER. CEER is the efficiency rating on the EnergyGuide label (BTU per watt-hour). Median values for ENERGY STAR certified 115 V window units:
| Size | Models | Median CEER | Watts while cooling |
|---|---|---|---|
| 5,000 BTU | 21 | 14.4 | ≈ 347 W |
| 8,000 BTU | 94 | 15.0 | ≈ 533 W |
| 10,000 BTU | 92 | 15.0 | ≈ 667 W |
| 12,000 BTU | 111 | 15.0 | ≈ 800 W |
Source: U.S. EPA ENERGY STAR Certified Room Air Conditioners list, window type, pulled 2026-11-02. Older units use more: the Champion chart lists 450–600 W running and 900–1,200 W starting for 5,000 BTU, and 900–1,200 W running and 1,800–2,400 W starting for 10,000 BTU (checked 2026-11-02).
Step 2: Runtime math
Hours = battery Wh × 0.85 ÷ (AC watts × share of time the compressor runs). Assumptions: 85% usable; 50% cycling is an example, hot days run closer to 100%
| Station (capacity, output, surge) | 5,000 BTU, nonstop | 5,000 BTU, 50% on | 10,000 BTU, nonstop | 10,000 BTU, 50% on |
|---|---|---|---|---|
| Anker SOLIX C1000 (1,056 Wh, 1,800 W, 2,400 W surge) | ≈ 2.6 h | ≈ 5.2 h | ≈ 1.3 h | ≈ 2.7 h |
| Jackery Explorer 2000 v2 (2,042 Wh, 2,200 W, 4,400 W surge) | ≈ 5.0 h | ≈ 10.0 h | ≈ 2.6 h | ≈ 5.2 h |
| EcoFlow DELTA Pro 3 (4,096 Wh, 4,000 W, 6,000 W surge) | ≈ 10.0 h | ≈ 20.1 h | ≈ 5.2 h | ≈ 10.4 h |
| Jackery Explorer 5000 Plus (5,040 Wh, 7,200 W, 14,400 W surge) | ≈ 12.3 h | ≈ 24.7 h | ≈ 6.4 h | ≈ 12.9 h |
Capacities and ratings from our power station table (October 2026). Example: 2,042 Wh × 0.85 ÷ 347 W = 5.0 hours.
Step 3: Check output and surge
The station's continuous output must cover the running watts, and its surge must cover the start. On the Champion chart, a 10,000 BTU unit can need up to 2,400 W to start, which is right at the C1000's 2,400 W surge rating, so a bigger station is the safer pick for that size. Inverter (variable-speed) window units ramp up gently and are easier on a battery.
Longer heat waves
Air conditioning is one of the hardest loads to carry on batteries alone. For days of outage, look at solar recharging (solar backup), a generator (power station vs generator cost), or an installed battery (whole-home battery cost).
Add your AC and essentials in the calculator → · Sizing guide
FAQ
How long will a power station run a window AC?
A 2,042 Wh station runs an efficient 5,000 BTU window unit (about 347 W) for about 5.0 hours with the compressor on nonstop, or about 10.0 hours if it cycles on half the time. A 10,000 BTU unit (about 667 W) roughly halves that.
How many watts does a window air conditioner use?
The Champion wattage chart lists 450–600 W running for a 5,000 BTU unit and 900–1,200 W for a 10,000 BTU unit. Newer ENERGY STAR units use less: cooling BTU per hour divided by the CEER rating gives the watts.
Will a 1,000 Wh power station run a window AC?
For a short time. A small 5,000 BTU unit would run about 2.6 hours nonstop on a 1,056 Wh station. The starting surge (900–1,200 W for 5,000 BTU on the Champion chart) is within the C1000's 2,400 W surge rating.
Is it better to cool one room?
Yes. Cooling one small bedroom with a small unit, with the door closed and blinds drawn, is the most realistic use of a portable station in a summer outage.
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