About 13.3 hours. A 500 Wh power station has roughly 425 Wh usable, and a mini fridge averages about 32 W because the compressor cycles on and off. Depending on the model the range is about 8.9 to 21.2 hours.
- Runtime
- 13.3 hEstimate at average draw
- Usable energy
- 425 Wh85% of 500 Wh
- Average draw
- 32 W80 W while running
- Surge
- 400 WCheck the surge rating
The math
| Usable capacity | 500 Wh × 0.85 = 425 Wh |
|---|---|
| Average draw | 80 W running × 0.4 duty = 32 W |
| Runtime | 425 ÷ 32 = 13.3 h |
Things to check
- The power station's surge rating must cover the 400 W start-up surge, or it will shut off when the compressor kicks in. Many smaller units can't.
- Food-safety guidance says a closed fridge stays cold about 4 hours and a full freezer about 48 hours, so you can run it in shifts to stretch the battery.
Other battery sizes
Questions people ask
How long will a 500 Wh power station run a mini fridge?
About 13.3 hours (about 13.3 hours). A 500 Wh power station has roughly 425 Wh usable, and a mini fridge averages about 32 W because the compressor cycles on and off. Depending on the model the range is about 8.9 to 21.2 hours.
How many watts does a mini fridge use?
A mini fridge typically draws about 80 watts while running (roughly 50-120 W) and uses about 0.75 kWh a day. Its compressor surges to a few hundred watts for a moment at startup.
How do you calculate power station runtime?
Hours ≈ capacity in Wh × 0.85 ÷ average watts. The 0.85 allows for inverter and battery losses.