Quick answer: if you already have a good primary pump, add a standalone backup like the Zoeller Aquanot Fit 508. If your primary pump is old, a combination system like the Basement Watchdog Big Combo CONNECT replaces both at once. The Wayne ESP25n is a simpler backup with a basic alarm.
Pennsylvania’s Department of Environmental Protection describes the state as one of the most flood-prone states in the nation, based on the flood damage it has seen [1]. For a house with a basement, that risk often comes down to one machine: the sump pump. It runs on household power, so it stops when an outage hits, which is often during the same storm that’s filling the pit. Ready.gov, the federal preparedness site, says to consider a sump pump with a battery [2].
Why it matters in Pennsylvania
How we chose
- Measured flow at 10 feet. A pump’s flow at 0 feet of lift isn’t realistic for a basement. We list the flow at 10 feet where the maker publishes it.
- Run time on battery. We report the maker’s run-time claims along with the conditions behind them (usually a 10% duty cycle).
- Alarms. A backup only helps if you know it’s running or failing, so we list what each controller warns you about.
- Recall check. We searched the CPSC recall database on November 2, 2026, and found no recalls for these models. The only recent Wayne recall was for a different product, the WaterBUG GLOW multi-use pump [6].
Our picks
Best for: Adding a backup to a pump you already trust
Zoeller Aquanot Fit 508 Battery Backup System (508-0014)
Strong flow at 10 feet, built-in Wi-Fi, and an included high-water sensor that sounds an alarm and starts the pump in an emergency.
- 34 GPM at 10 ft. (12.7 volts) [3]
- 2 days of battery protection at a 10% duty cycle; 5.5 hours continuous run [3]
- Built-in Wi-Fi; alerts for power outage, high water, pump, switch, battery and charger faults [3]
- Battery box fits group 27, 29 and 31 batteries [3]
- 3-year warranty [3]
Safety check: Zoeller's sales sheet doesn't list a safety certification. CPSC recall search found no recall for this model (checked 2026-11-02); Zoeller's last recall was for septic pumps in 2007.
Watch out: Model 508-0014 doesn't include a primary pump, and a battery is not listed among its contents, so the full cost is higher than the box price.
See it on Amazon → We chose it from specs and safety records; we haven't tested it ourselves.
Best for: Replacing an old primary pump and adding a backup at once
Basement Watchdog Big Combo CONNECT (CITS-50)
A 1/2 HP primary pump and a battery backup in one assembly, so both are matched and installed together.
- Primary: 1/2 HP; 3,540 GPH at 10 ft. [4]
- Backup: 1,850 GPH at 10 ft. [4]
- About 48 hours on one AGM battery, 96 on two, at a 10% duty cycle [4]
- Remote terminal for a home security system; optional Wi-Fi module [4]
Safety check: Maker lists CSA certification for the main pump and cUL for the primary float switch, controller and backup charger. CPSC recall search found no Basement Watchdog recall (checked 2026-11-02).
Watch out: Basement Watchdog's page says this system does not alert you if the backup pump fails. The battery is sold separately.
See it on Amazon → We chose it from specs and safety records; we haven't tested it ourselves.
Best for: A simple backup with a basic alarm
Wayne ESP25n Battery Backup Sump Pump
A straightforward backup with a steel and cast iron build, a battery case with an LED display and audible alarm, and no app to set up.
- 2,700 GPH at 0 ft.; 1,500 GPH at 10 ft. [5]
- Removes up to 10,000 gallons on a single battery charge, per the maker [5]
- Epoxy-coated steel housing, cast iron base [5]
- Battery case with LED display and audible alarm [5]
Safety check: Wayne's product page doesn't list a safety certification. CPSC recall search found no recall for the ESP25n (checked 2026-11-02).
Watch out: The lowest flow at 10 ft. of these picks, and no remote alerts. The product page doesn't say whether a battery is included or how long the warranty runs.
See it on Amazon → We chose it from specs and safety records; we haven't tested it ourselves.
Buying guide
- Know your lift. Measure from the bottom of the pit to where the discharge pipe leaves the house; compare pumps at that height, not at 0 feet.
- Pick the battery deliberately. Makers rate run time with specific batteries; Basement Watchdog uses its own AGM battery, and Zoeller’s box takes group 27, 29 or 31 batteries [3][4].
- Get an alarm you’ll hear. If nobody is home during a storm, remote alerts by app, text or a security system matter more than a beep in the basement.
- Test it. Zoeller’s controller can test the pump on a schedule [3]; with others, pour water into the pit now and then to make sure the backup kicks on.
- Look at flood insurance too. A pump protects against groundwater and outages, not a river overtopping its banks.
Sources
Common questions
Why do I need a battery backup sump pump?
A regular sump pump runs on household power, so it stops in an outage, often during the same storm that's filling the pit. A battery backup pump takes over when the main pump can't run. Ready.gov's flood guidance says to consider a sump pump with a battery.
Are batteries included with backup sump pumps?
Often not. Basement Watchdog's Big Combo CONNECT page lists the battery as sold separately, and Zoeller's Aquanot Fit 508 has a battery box that holds group 27, 29 or 31 batteries. Budget for the battery when you compare prices.
When should I buy flood insurance?
Well before you need it. Ready.gov notes that a flood insurance policy typically takes up to 30 days to go into effect.