Power station for a well pump: size, 240 V and surge
No power, no water. A well pump is a motor, so the same two numbers matter as for a sump pump: the start-up surge and how long it really runs. Many well pumps also run on 240 V, which most portable power stations cannot supply.
Typical numbers
| Item | Typical running | Typical start-up surge | Per day |
|---|---|---|---|
| Well pump, 1/2 HP (240 V) | 1,000 W | about 3,000 W | about 1,900 Wh |
Typical values, assuming the pump runs about 8% of the day (about 2 hours) with normal household use. The nameplate on your pump (volts, amps, HP) wins; 1 HP pumps and deep wells draw more.
Check the voltage first
Look at the pump's nameplate or the breaker: a double-pole breaker means 240 V. Most portable stations only offer 120 V outlets, so they cannot run a 240 V pump directly. Some larger stations and home batteries offer 240 V (split phase), and some 120 V pumps exist. Hard-wired pumps need an electrician and a permit where required; never back-feed the panel without an interlock or transfer switch.
Worked example
1,000 W × 24 h × 0.08 = about 1,900 Wh a day. With 85% of rated capacity usable:
| Battery rating | Usable | Pump runtime at this duty |
|---|---|---|
| 1,000 Wh | 850 Wh | about 10 hours |
| 2,000 Wh | 1,700 Wh | about 21 hours |
| 3,000 Wh | 2,550 Wh | about 32 hours |
A storage tank or pressure tank means the pump runs in bursts; conserving water stretches these numbers a lot.
Good to know
- Check the station's surge rating against about 3,000 W, not just its continuous rating.
- A soft-start kit can reduce the surge a station must supply; see the soft-start tool.
- Fill a few containers while you have power and run the pump in short bursts.
Open the calculator with a well pump filled in
Appliance figures are typical values, not measurements of your device: the label or a plug-in watt meter on yours wins. The sums assume 85% of a battery's rated capacity reaches your outlets (how the numbers work). We list no prices and have not hands-on tested any product.
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