What size generator to run a well pump?
Check, uncheck or adjust the typical device list below — watts, startup surge and battery size update instantly. Numbers come from U.S. DOE, ENERGY STAR and manufacturer spec sheets, not marketing copy.
1. Check what you need to power
Refrigeration & Freezers
Kitchen
Heating, Cooling & Fans
Water & Pumps
- 1
Laundry & Cleaning
Electronics & Office
Medical Devices
Power Tools & Outdoor
Lighting
2. Your sizing
⚠️ Your selection includes 240V equipment (submersible pump / central AC / dryer) — you need a split-phase (120/240V) station or a transfer switch setup. Verify nameplate watts and starting amps before buying; consult a licensed electrician for fixed wiring.
Assumptions: daily hours per device follow DOE / ENERGY STAR duty cycles; capacity adds a 25% margin. Check your appliance nameplates — actual draw varies by model.
3. Best matches from our 6-brand database
- Anker SOLIX F3800~$2,199
- rated 6,000W covers your 1,270W continuous load
- surge 9,000W covers your 7,400W start peak
- 6.7 days of your typical daily use (3,840Wh / 575Wh)
- 120/240V split-phase output
- EcoFlow DELTA Pro 3~$2,799
- rated 4,000W covers your 1,270W continuous load
- surge 8,000W covers your 7,400W start peak
- 7.1 days of your typical daily use (4,096Wh / 575Wh)
- 120/240V split-phase output
Static answer (crawlable summary)
Typical device list: Submersible Well Pump (1/2 HP, 240V)×1.
Estimated from: Franklin Electric (AID/AIM)
| Continuous load | 1,150 W |
|---|---|
| Startup peak | 7,400 W (driven by 1× Submersible Well Pump (1/2 HP, 240V)) |
| Daily energy use | 575 Wh |
| Recommended capacity | 720 Wh (25% margin included) |
| Minimum inverter | 1,270 W continuous |
Frequently asked questions
What size generator to run a well pump?
For a typical setup (Submersible Well Pump (1/2 HP, 240V)), you need at least 1,150W of continuous power. The single biggest moment is startup: when 1× submersible well pump (1/2 hp, 240v) kicks on, the momentary draw peaks at 7,400W. For a full day of runtime we recommend at least 720Wh of battery capacity (your devices use about 575Wh per day, plus a 25% margin for a full day of use).
Which power stations can handle this?
Based on published specs, Anker SOLIX F3800, EcoFlow DELTA Pro 3 cover the 7,400W startup peak and deliver 6.7 days / 7.1 days of typical daily use. Check the comparison cards above for the full numbers.
Why is the startup surge higher than the running watts?
Motor-driven devices (fridge compressors, well pumps, air conditioners) draw 2-5× their running power for a split second at startup — measured as locked-rotor amps (LRA). On this page the biggest spike comes from the Submersible Well Pump (1/2 HP, 240V): a station that only meets the running load will trip or stall when it starts. Data sources: U.S. DOE Energy Saver, ENERGY STAR certified products, manufacturer spec sheets.