Use-case guide ยท 2026

Best generator for a Sump Pump

Sump pumps have the cruelest failure mode in the house: the same storm that floods your basement is the one that kills the power. A generator (or battery backup) for the sump pump routinely pays for itself in one avoided insurance claim.

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The power requirements

Running watts

800W (โ…“ HP) to 1,050W (ยฝ HP)

Starting surge

1,300โ€“2,200W depending on horsepower

  • โ–ธStarting surge is the number that matters โ€” a ยฝ HP pump can briefly demand over 2,000W.
  • โ–ธDuring active flooding a pump may cycle every minute or two, so fuel/battery consumption is much higher than for a fridge.

Adding more appliances? Run your full load through the sizing calculator โ†’

Our picks

Automatic battery option
EcoFlow DELTA Pro

Plug the pump into the DELTA Pro with pass-through power and it functions as a giant UPS: the instant utility power drops, the pump keeps running on battery with zero action from you โ€” crucial if the outage starts while you're asleep or away.

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$1,899on Amazon

Price as of Sep 23, 8:40 AM ET โ€” subject to change.

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Before you buy

  • โ–ธThe battery-as-UPS setup is the only option that works when nobody's home โ€” a generator can't start itself.
  • โ–ธCheck your pump's HP rating on the housing; โ…“ HP vs ยฝ HP changes the surge math.
  • โ–ธA water-powered backup sump pump (no electricity at all) is a smart belt-and-suspenders addition if you have municipal water.

Frequently asked questions

Will a battery station keep a sump pump running automatically?

Yes โ€” plug the pump into a station that supports pass-through/UPS operation and it switches to battery instantly when the grid drops. A 2โ€“3.6kWh unit typically covers several hours of heavy pumping; pair with a generator for multi-day storms.

What size generator do I need for a ยฝ HP sump pump?

At least 2,200W peak capacity for the pump alone; a 3,000โ€“4,500W class unit is the practical choice so the fridge and lights can run alongside it.

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