Sump pump and power outages: backup options and alarms
Short answer: A standard sump pump stops when the power goes out. The usual protections are a battery backup pump (a second pump on its own deep-cycle battery), a water-powered backup pump where city water pressure allows, or a generator. A high-water alarm that runs on 12-volt DC power or has Wi-Fi alerts tells you when water is rising so you can act. We sell alarms and floats, not backup pumps.
Safety: Never run a generator indoors or in a garage. Generator connections to house wiring need a transfer switch installed by an electrician.
Step by step
- Know your risk. Think about how often your pump runs in storms and how long outages last where you live.
- Pick a backup. Battery backup pumps are common in finished basements. Water-powered units need adequate municipal water pressure and local code approval. Generators need safe outdoor placement and correct connection.
- Add warning. Install a high-water alarm with its own float set above the pump's turn-on level. A 12-volt DC alarm can be powered from a battery or solar setup.
- Maintain it. Test backup pumps and alarms a few times a year and replace backup batteries on the maker's schedule.
Alarms that warn you
- 12VDC High Water Alarm — 10 — $169.81
- 12VDC High Water Alarm — 100 — $290.88
- 12VDC High Water Alarm — 16 — $175.31
- SA-120V-1L-WIFI Alarm minus float — $194.90
- DC Floor Water Leak Sensor — 30 Foot — $30.02
Common questions
How long does a sump battery backup last?
It depends on the battery size and how often the pump cycles, so check the backup system maker's run-time chart.
Will a high-water alarm work in a power outage?
Standard 120-volt alarms need power. A 12-volt DC alarm wired to a battery keeps working; some Wi-Fi alarms also need your internet to stay up to send alerts.
Do you sell sump backup batteries?
Not currently. We list high-water alarms, float switches and leak sensors.
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Related categories: Sump & Effluent Pumps & Alarms. General information only; follow the equipment maker's instructions and local codes. Updated 2026-11-14.