Sump Pump Battery Backup: Is It Worth It?

A sump pump does its most important work during heavy rain and storms, which is exactly when the power tends to go out. A backup pump keeps water moving when the main pump can’t.

Why main pumps fail at the worst time

• Power outages during storms
• Stuck float switches: the pump never gets the signal to turn on
• Overload: more water than one pump can handle
• Age: pumps wear out, often without warning
• Frozen or clogged discharge lines in winter

Types of backup

• Battery backup pump: a second pump in the same pit that runs off a deep-cycle battery when the main pump stops or the power goes out. The most common choice. Batteries need checking and replacing every few years.
• Water-powered backup: uses city water pressure to pull water out of the pit, so it doesn’t need electricity. Only works with municipal water, and uses water while running. Check local plumbing code.
• Generator: keeps the main pump (and more) running in outages, but doesn’t help if the pump itself fails.
• High-water alarm: inexpensive; alerts you so you can act before the water reaches the floor.

Is it worth it for you?

A backup makes the most sense if:

• Your pump runs often, or water has reached the floor before
• You have a finished basement, or store things that would be costly to lose
• Your area loses power in storms
• You travel and the house sits empty

If your pump rarely runs and the basement is unfinished, a high-water alarm alone may be enough.

Simple maintenance

• Pour a bucket of water into the pit every few months to test the pump.
• Make sure the discharge pipe outside isn’t frozen, crushed or pointing back at the house.
• Test the backup too, and note the battery’s install date.

Need a new pump, a replacement or a backup installed? See sump pump installation.