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If you’re on a well, an outage isn’t just dark — it’s no water. No taps, no shower, no flushing toilets, and if you have livestock, no trough. That’s why well owners tend to buy backup power sooner than anyone else, and it’s also why they’re the most likely to buy the wrong thing.
The trap is simple. Most of the big, well-reviewed, heavily marketed power stations are 120V only. A residential submersible well pump is 240V. It doesn’t matter how many watt-hours the battery holds; the voltage is wrong and the pump will not run. People find this out after the purchase.
The two specs that decide it
1. Split-phase 240V. Non-negotiable. Your pump is wired for it. This single requirement eliminates most of the market.
2. Surge headroom. A pump motor draws far more current in the instant it starts than it does while running — commonly three to six times its running wattage. Size to the surge, not the average:
| Pump | Typical running watts | Plan for startup surge |
|---|---|---|
| 1/2 HP | ~750W | ~2,300–4,500W |
| 3/4 HP | ~1,000W | ~3,000–6,000W |
| 1 HP | ~1,200W | ~3,600–7,200W |
| 1.5 HP | ~1,800W | ~5,400W and up |
Find your pump’s plate — it lists horsepower and often locked-rotor amps, which is the surge figure. If it’s inaccessible down the well, the pressure tank or the breaker size will tell you roughly what you’re dealing with. A soft starter, if your pump has one, cuts that surge substantially.
What actually runs one
| System | Why it works | Price | Buy |
|---|---|---|---|
| Anker SOLIX F3800 Plus (our pick) | Split-phase 120V/240V, expandable. Cheapest way to get the voltage a pump needs. | $3,499.99 | Check price → |
| EcoFlow DELTA Pro Ultra Smart Home Kit | 7,200W output and 6,144Wh — the most surge headroom here, for a 1.5 HP pump or a pump plus heavy loads. | $7,769.00 | Check price → |
| EcoFlow DELTA Pro Ultra Deluxe | Same platform, more storage and solar — for long outages where the pump runs daily for a week. | $12,879.00 | Check price → |
Prices as listed at the time of writing.
How much battery a week of water takes
Running the pump costs less than people fear. A household using around 150 gallons a day typically runs the pump 30 to 60 minutes total, spread across the day — call it 0.5 to 1kWh. Even at the high end, a 6,144Wh system carries roughly six days of pumping if that were all it did.
It won’t be. Add the fridge, the freezer, the lights, and Wi-Fi and you’re realistically at a day to a day and a half per charge. That’s why solar input matters more here than anywhere: the DELTA Pro Ultra accepts up to 5.6kW of panel, enough to refill in a strong day and keep the water flowing indefinitely. Our panel comparison covers what that actually costs.
▶ See the DELTA Pro Ultra Smart Home Kit — $7,769.00 code CHADPENFOLD — 10% off
The wiring is not optional
A submersible pump is hard-wired to your panel. There’s no plug to move. Connecting backup power means a transfer switch or smart panel, installed by a licensed electrician and permitted in most places. Get that quote before you choose a system — it can be a four-figure line item and it may change which unit makes sense.
One warning worth stating bluntly: never backfeed a circuit through a dryer outlet or a homemade cord. It can energize the utility line outside and kill a lineman working to restore your power. It also destroys equipment and voids insurance. Transfer switch, every time.
Two cheap things that stretch any system
- A pressure tank that’s correctly charged means the pump cycles less, which cuts both surges and runtime. Check the air charge against the cut-in pressure.
- Store water before the storm. Filling the bath and a few jugs costs nothing and takes a day’s demand off the battery entirely. Backup power is for when that runs out.
The pick
For most well owners, the Anker SOLIX F3800 Plus at $3,499.99 is the right answer: it clears the 240V bar that eliminates most of the market, at the lowest price that does. Step up to the DELTA Pro Ultra if you have a 1.5 HP pump, a long outage history, or want the 5.6kW solar input that makes the water last as long as the sun does.
▶ Buy the Anker SOLIX F3800 Plus — $3,499.99 code CHADPENFOLD — 10% off
Keep reading: EcoFlow vs Anker head to head · Cheapest way to get 240V backup · All gear comparisons