Zero-guess planning tool
How long will a power station run it?
Pick a battery size along the top and an appliance down the side. Each cell is a rough runtime from a full charge, so you can size a unit to the outage you're planning for.
| Appliance (running watts) | 512 Wh | 1.02 kWh | 2.05 kWh | 3.84 kWh |
|---|---|---|---|---|
| CPAP machine 150 W | 2.9 hr | 5.8 hr | 12 hr | 22 hr |
| TV, computer & Wi-Fi 400 W | 1.1 hr | 2.2 hr | 4.4 hr | 8.2 hr |
| LED lighting (whole house) 500 W | 52 min | 1.7 hr | 3.5 hr | 6.5 hr |
| Refrigerator 700 W · cycles: runs longer in practice | 37 min | 1.2 hr | 2.5 hr | 4.7 hr |
| Furnace blower 800 W | 33 min | 1.1 hr | 2.2 hr | 4.1 hr |
| Sump pump 800 W · intermittent | 33 min | 1.1 hr | 2.2 hr | 4.1 hr |
| Microwave 1,000 W | 26 min | 52 min | 1.7 hr | 3.3 hr |
| Space heater 1,500 W | 17 min | 35 min | 1.2 hr | 2.2 hr |
How these are calculated
Runtime = (battery capacity × 85% usable) ÷ the appliance's running watts. The 85% allowance covers inverter losses and the gap between nameplate and usable capacity. Wattages are typical US DOE / manufacturer figures, the same ones behind our sizing calculator (estimates, not measurements).
Real life runs longer for cycling loads. A refrigerator's compressor only runs about a third of the time, so a fridge lasts roughly 2-3× the continuous figure shown. Heaters and lights, which draw steadily, track the table closely.
Ready to pick one? See our best solar generators
Go deeper