How long will a power station run my devices?
Runtime depends on two numbers: how much energy the battery stores (watt-hours, Wh) and how much power your devices draw on average (watts, W). Some energy is lost converting battery power to 120 V AC, typically 10–20%.
Example: a 1,024 Wh EcoFlow DELTA 3 running a 55 W average fridge load: 1,024 × 0.85 ÷ 55 ≈ 15.8 hours.
Runtime table: common devices by battery size
Estimated hours of continuous use at 85% efficiency. Fridges and freezers use their average draw because the compressor cycles on and off.
| Device (avg. draw) | 300 Wh | 500 Wh | 1,000 Wh | 2,000 Wh | 3,600 Wh |
|---|---|---|---|---|---|
| Refrigerator (full size) (55 W) | – | 7.7 h | 15.5 h | 30.9 h | 2.3 days |
| Chest freezer (35 W) | – | 12.1 h | 24.3 h | 2 days | 3.6 days |
| CPAP (no humidifier) (40 W) | 6.4 h | 10.6 h | 21.3 h | 42.5 h | 3.2 days |
| CPAP (with heated humidifier) (90 W) | 2.8 h | 4.7 h | 9.4 h | 18.9 h | 34 h |
| Wi-Fi router + modem (15 W) | 17 h | 28.3 h | 2.4 days | 4.7 days | 8.5 days |
| Starlink (Standard) (65 W) | 3.9 h | 6.5 h | 13.1 h | 26.2 h | 47.1 h |
| Laptop (50 W) | 5.1 h | 8.5 h | 17 h | 34 h | 2.6 days |
| TV (55" LED) (100 W) | 2.5 h | 4.3 h | 8.5 h | 17 h | 30.6 h |
| Box / pedestal fan (50 W) | 5.1 h | 8.5 h | 17 h | 34 h | 2.6 days |
| Electric blanket (60 W) | 4.3 h | 7.1 h | 14.2 h | 28.3 h | 2.1 days |
| Oxygen concentrator (300 W) | 51 min | 1.4 h | 2.8 h | 5.7 h | 10.2 h |
| Window AC (8,000 BTU) (550 W) | – | – | 1.5 h | 3.1 h | 5.6 h |
“–” = the device's running watts exceed what most stations of that size can output.
Why your real runtime may be shorter
- Inverter losses: AC outlets lose 10–20%. Using the 12 V or USB-C ports directly is more efficient.
- Cold weather: lithium batteries deliver less capacity below 32 °F (0 °C).
- Idle draw: leaving the AC inverter on with nothing plugged in still uses 10–30 W.
- Start-up surge: fridges, pumps and AC units need 2–7× their running watts for a second when they start. If that exceeds the station's surge rating, it shuts off even though the battery is full.
- Battery age: LiFePO4 keeps about 80% of its capacity after 3,000+ cycles; older NMC batteries fade faster.
How to make a power station last longer
- Run 12 V devices (fridges, fans, CPAP with a DC cable) from the DC port to skip inverter losses.
- Turn the AC output off when you don't need it.
- Add solar: even a 200 W panel adds ~600–900 Wh on a sunny day. Calculate solar recharge time.
- Choose an expandable unit so you can add an extra battery later.
Frequently asked questions
How long will a 1000Wh power station run a refrigerator?
A modern full-size fridge averages about 50–60 W over a day (it cycles on and off), so a 1,000 Wh power station runs it for roughly 15.5 h. Older or larger fridges can use twice as much.
How long will a power station run a CPAP machine?
A CPAP without humidifier draws about 40 W, so a 300 Wh station lasts about 6.4 h, or 0 nights of 8 hours. With a heated humidifier (≈90 W) runtime drops by more than half. Using the CPAP's DC adapter extends runtime by 10–15%.
How long will a power station run Starlink?
Starlink Standard averages about 65 W, so a 1,000 Wh unit runs it about 13.1 h. Starlink Mini uses about 25 W, giving roughly 34 h.
Is the Wh rating the usable capacity?
No. The rated Wh is the battery size. After inverter losses you typically get 80–90% of it as AC power, which is why the calculator uses 85%.
Can I run a power station while it charges?
Most modern units support pass-through charging, so you can power devices while the station charges from the wall or solar.
Related calculators
Runtime guides by device
- How long will a power station run a refrigerator?
- How long will a power station run a chest freezer?
- How long will a power station run a CPAP machine?
- How long will a power station run a CPAP with heated humidifier?
- How long will a power station run an oxygen concentrator?
- How long will a power station run a Starlink?
- How long will a power station run a Starlink Mini?
- How long will a power station run a TV?
- How long will a power station run a laptop?
- How long will a power station run a window air conditioner?
- How long will a power station run a space heater?
- How long will a power station run an electric blanket?
- How long will a power station run a Wi-Fi router?
- How long will a power station run a mini fridge?
- How long will a power station run a microwave?
- How long will a power station run a coffee maker?
- How long will a power station run a sump pump?
- How long will a power station run a desktop computer?
- How long will a power station run a gaming PC?
- How long will a power station run a game console?
- How long will a power station run an e-bike charger?
- How long will a power station run a box fan?