It comes down to two numbers people constantly confuse: output watts (can it switch the thing on?) and capacity in watt-hours (how long will it last?). Here's what each size class realistically powers.
Runs: phones, tablets, laptop, LED lights, WiFi router, a fan, a CPAP for part of a night, a mini-fridge for a few hours.
Won't run: kettles, microwaves, heaters, hair dryers — most 300Wh units cap out around 300W output.
Runs: everything above for longer, plus a small TV, a drone/camera charging station, a projector for a movie night, a CPAP overnight (humidifier off).
Runs: a full-size fridge for 12–17 hours (it cycles), a CPAP 2–3 nights, corded power tools (mind the surge), a blender, a microwave in short bursts. Most 1000Wh units output 1,000–1,500W.
Runs: fridge + lights + internet + phones through a long outage, a coffee maker, microwave, a small window AC for a couple of hours, most power tools. Output is usually 2,000W+.
Runs: the above for a day or more, and pairs with solar to recharge daily. Expandable models reach 5,000Wh+ for near-whole-home coverage of essentials.
| Appliance | Output needed | Sensible capacity |
|---|---|---|
| Phone / laptop / lights | ~100 W | 300 Wh |
| CPAP (overnight) | ~60 W | 500–1000 Wh |
| Full-size refrigerator | 800 W (surge) | 1000–2000 Wh |
| Microwave | 1000–1500 W | 1000 Wh+ |
| Coffee maker / kettle | 1000–1200 W | 1000 Wh+ |
| Window AC (5,000 BTU) | 1100 W (surge) | 2000 Wh+ |
| Space heater (1500W) | 1500 W | 2000 Wh+ (≈1.5 hrs only) |
The power station size calculator adds up your specific appliances and tells you the capacity and output to look for — surge included.
Open the calculator →Phones, laptop, lights, router, a fan, a CPAP for part of a night, a mini-fridge a few hours. Not high-watt items (kettle, microwave, heater) — output is ~300W.
Yes, with a 1000Wh+ unit rated for 1000W+ output. It runs in short bursts and uses a fair bit of capacity each time.
Only larger units, and only ~1.5 hours even on 2000Wh — resistive heat drains batteries fast. Propane/diesel is better off-grid.