- Sump Pumps & Basements
- Sump pumps
- Storm season
- 7-minute read
The pump fails when the lights go out, and the lights go out when it is raining hardest. For any Racine-area basement that has taken water before — and for the homes just converted under the city's sump pump program — this is the missing piece.
If your basement has ever taken water and your neighborhood loses power in storms, yes. A sump pump battery backup is a second, DC-powered pump in the same pit that takes over when the main pump loses power or fails. Manufacturers rate a charged deep-cycle battery for several hours of typical cycling — enough to outlast most summer outages.
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Key takeaways
- A backup pump protects against two failures at once: power loss and primary-pump failure. The battery is only half the reason to have it.
- Run time depends on how often the pit fills, not just battery size; a wet spring in clay soil drains a battery faster than a summer storm.
- Homes converted under the Racine Sump Pump Program now depend on a pump for the first time and rarely have backup.
- A water-powered backup is an option on city water; it is not an option on a private well.
Why does a sump pump need a battery backup at all?
A primary sump pump is a 120-volt appliance. Every scenario that fills the pit fastest — a July thunderstorm, a March thaw with rain on frozen ground — is also the scenario most likely to drop a line somewhere in Racine County.
The pit does not know the power is out. Groundwater keeps rising through the drain tiles, and without a pump it reaches the basement floor in minutes to hours depending on the soil.
Power outage
Storm outages, a tripped GFCI, an unplugged cord for the holiday lights. The backup's DC pump runs off the battery until power returns.
Primary pump failure
A stuck float, a burned-out motor or a jammed impeller. The backup's float sits higher in the pit and lifts when the primary fails to keep up, power or no power.
Which Racine-area homes need a sump pump battery backup most?
Basement has flooded before
Finished basements, furnace and water heater on the floor, storage on the slab. One outage is the whole cost of the backup several times over.
Converted under the city program
Pre-1954 Racine homes that just moved from a Palmer valve to a sump pump are relying on a pump for the first time. The Palmer valve guide explains the program; a backup is the logical next step.
High water table or clay soil
Mt Pleasant, Sturtevant and the lower parts of Caledonia see pumps cycling every few minutes in a wet spring. A backup is also a spare for when the primary wears out early. A Franklin plumber or an Oak Creek plumber from our shop sees the same cycling on the clay subdivisions there.
A home on a hill with a pump that runs a few times a year in April is the one case where a backup is a preference rather than a need.
For how many hours does a sump pump battery backup actually run?
Long enough for a typical outage; not indefinitely. Two things set the number.
- Battery capacity: a deep-cycle AGM battery in the common sizes gives most systems several hours of intermittent pumping. Manufacturer run-time charts assume a pump cycle of roughly once every few minutes.
- Cycle rate: a pit that fills every 45 seconds in a March thaw uses the battery several times faster than one that fills every ten minutes. Constant cycling is the worst case.
- Battery age: AGM batteries lose capacity after three to five years. A backup that has never been tested may be running on a fraction of its rating.
- Pump size: a bigger DC pump moves more water per cycle but draws more current; the better systems match pump to battery rather than maximizing either.
Unplug the primary, pour water into the pit until the backup float lifts, and time a few cycles. The sump pump test guide covers the primary; the backup gets the same test with the main pump unplugged.
What are the options besides a battery?
| Backup type | Needs | Fits | Does not fit |
|---|---|---|---|
| Battery backup (DC pump) | Deep-cycle battery, charger, its own discharge or a shared line with check valves | Most Racine County homes | Homes with no reliable place for the battery near the pit |
| Water-powered backup | Municipal water pressure; uses city water to lift pit water by venturi | Racine, Mt Pleasant and Sturtevant homes on city water | Any home on a private well — no pressure without power |
| Standby generator | Natural gas or propane; runs the whole panel or a circuit | Homes that also want the furnace and refrigerator covered | Budget-only purchases; still needs a second pump for primary failure |
| Combination primary/backup unit | One housing with an AC pump and a DC pump | Replacing an old primary anyway | Pits too small for the taller assembly |
PM installs battery and water-powered backups and, through its generator installation service, whole-home standby power for homes that want everything covered.
Storm season comes every summer. Get a sump pump battery backup quoted before the next one — PM sizes the battery to how often your pit actually cycles.
Call (262) 770-0039Request serviceWhat does installation involve?
Check the pit and discharge
The basin needs room for a second pump and float. The discharge either gets its own line or ties into the primary's with a second check valve.
Mount the backup pump
It sits a few inches above the primary so the primary does the everyday work and the backup only runs when water rises past it. This is the sump pit only — a sealed basement-bath basin is an ejector pump, a different system.
Place the battery and charger
On a shelf or stand near the pit, off the floor, with the charger on a dedicated outlet. Most controllers sound an alarm when they take over or when the battery is low.
Test both pumps
Primary on power, then primary unplugged. The Racine sump pump service leaves both tested and the test written on the invoice.
Sump pump battery backup questions
How often should the backup battery be replaced?
Every three to five years for AGM batteries, sooner if the system has run through several long outages. Check the date written on the battery and test run time every spring.
Can I add a sump pump battery backup to my existing pump?
Usually. As long as the pit has room for a second pump and float, a backup can be added without replacing a working primary. Very small pits sometimes need a combination unit instead.
Will the backup handle a heavy storm on its own?
For a while. DC backup pumps move less water per minute than a good primary, so during a sustained downpour the pit level may hold higher than normal. That is by design — it is a bridge, not a replacement.
What drives the cost of adding a sump pump battery backup?
Battery capacity, whether the pit needs a second discharge line, and whether the primary pump is being replaced at the same time. PM quotes it after seeing the pit; there is no fixed package price.
Does a sump pump battery backup need maintenance?
Yes: a run-time test each spring, terminals checked for corrosion, and the charger confirmed on. Some systems have a test button and an alarm; use them.
Sump pump guides worth reading next
If you are not sure the primary works, start with the test guide. If it never stops running, the constant-running guide is the one.
Battery, water-powered or generator — PM installs the backup that fits your pit and your water service. Free estimates across Racine County. For most of Racine County, a plumber near you means the shop on Mt Vernon Way.
Call (262) 770-0039Request service