How long will a 1,000 Wh power station actually last?
Short answer: Expect about 850 usable watt-hours from the AC outlets of a 1,000 Wh station. That runs a router for about 34 hours, a CPAP without humidifier for 2–3 nights, a modern refrigerator for 11–16 hours, and a 1,500 W space heater for about 35 minutes.
Runtime by load
Computed for a 1,000 Wh station at 85% AC efficiency (95% on USB/DC), starting full.
| Load | Draw | Output | Runtime |
|---|---|---|---|
| Wi-Fi router + modem | 25 W | AC | 34 h |
| Phone charging (USB, 10 W) | 10 W | USB/DC | 95 h |
| CPAP, no humidifier | 30 W | AC | 28 h |
| CPAP with heated humidifier | 60 W | AC | 14 h |
| Refrigerator, 150 W, 35% duty | 150 W × 35% | AC | 16 h |
| Refrigerator, 150 W, 50% duty | 150 W × 50% | AC | 11 h |
| Laptop | 50 W | AC | 17 h |
| 55" LED TV | 100 W | AC | 8.5 h |
| Box fan, medium | 60 W | AC | 14 h |
| Microwave 1,000 W | 1,000 W | AC | 51 min |
| Space heater 1,500 W | 1,500 W | AC | 34 min |
Why not the full 1,000 Wh?
The battery stores DC. To give you 120 V AC, an inverter converts it and loses 10–20% as heat. On top of that, the inverter itself draws power just by being on — commonly 10–30 W — which is why small loads are so much better on the USB or 12 V ports. A 10 W phone charger on USB uses the battery about twice as efficiently as the same charger plugged into the AC outlet.
Fridges cycle, so they last longer than the label suggests
A refrigerator's compressor runs on and off. In a closed, full fridge in a 70 °F room, it is on roughly a third to half of the time. The difference between 35% and 50% duty is the difference between about 16 and 11 hours on the same station. Keep the door shut, and if you can, measure your fridge's real draw for a day with a plug-in meter before an outage.
Make it last longer
- Turn the AC inverter off when nothing needs it; use USB-C and 12 V outputs where you can.
- For a CPAP, turn off the heated humidifier: it is most of the power draw.
- Recharge in daylight with solar panels: a 200 W panel in good sun adds about 800–1,000 Wh in a day.