Buying Guide · Updated 2026
A sump pump is only as reliable as the power behind it. The single biggest cause of failure isn't a worn motor — it's a power outage during the exact storm that's filling your pit fastest.
Municipal power grids tend to fail during the same heavy storms that push the most water into your sump pit — which means the moment your pump matters most is often the exact moment it loses power. A quality pump can run for roughly a decade with normal maintenance. None of that matters during a blackout unless something else is keeping it powered.
Before comparing brands, get two numbers from your existing setup:
Pull your current pump, check the label, and match or exceed that rating. Horsepower alone doesn't tell you what you need — capacity does.
Sump pump motors draw 2–3x their running wattage the moment they switch on. Your backup must handle that surge, not just steady-state draw.
| Type | How it works | Best for |
|---|---|---|
| Dedicated DC backup pump | A second smaller pump on a deep-cycle battery, float set higher than the main pump | Most homes — affordable, common |
| Inverter system | Your existing pump plugs into an inverter that switches to battery instantly on outage | Keeping your full-capacity pump running instead of a smaller one taking over |
| Portable power station / solar generator | Plugs into your existing pump, doubles as general home backup power | Homeowners wanting a multi-use device, not single-purpose hardware |
Top picks
A second pump, a maintained deep-cycle battery, and a float set to trigger only when the main pump can't keep up — that's the whole system, and it's sized for typical suburban seepage. Installs into your existing discharge pipe without much fuss.
When the outage isn't going to be over by morning, this is the one built for it — a controller tuned to stretch battery life over raw pumping speed.
You'll know the second something changes — the pump kicks on, the battery drops, the power cuts out — because it lands on your phone in real time.
Plug your existing full-horsepower pump straight into this and it just runs — no smaller backup pump taking over, no compromise on capacity. It recharges off solar or grid between events, and it's useful for a lot more than the sump pit.
Install a check valve on both the primary and backup discharge lines — without one, one pump just pumps water back into the pit through the other's line.
Give the backup pump its own discharge line where possible; if sharing a line, confirm the diameter handles both pumps running at once.
Mount the battery on a shelf or in a battery box — never directly on the pit floor, where dampness corrodes terminals.
Test the backup pump monthly by manually lifting its float switch to confirm activation.
FAQ
It comes down to how often the pump has to cycle. A 40 amp/hour battery might run 40–50 hours at once every 5 minutes — drop that to once a minute during a bad storm and you're looking at 10–12 hours instead.
Every 3 to 5 years. The charge indicator doesn't matter — replace it on schedule regardless of what it shows.
Only if one runs on independent power. Two pumps that both plug into the wall fail together in the same outage.
A backup pump solves groundwater and power-outage risk, not slow leaks. See our leak detector guide for that problem.