Best Value Battery Backup Systems for Sump Pumps

Last Updated on September 15, 2025 by Admin

A sump pump helps keep your basement or crawl space dry by moving water out before it can flood your home. But if the power goes out or the pump breaks, water can come in fast and cause expensive damage.

What is a Battery Backup System for a Sump Pump?

A battery backup for a sump pump keeps working when your main pump stops. This extra pump can save you from a wet basement and big repair bills.

Flooding is a risk almost everywhere. According to the Federal Emergency Management Agency (FEMA), 99% of U.S. counties have had a flood at some point, but most people do not have flood insurance. That means many families have to pay for repairs themselves after a storm.

Power outages are also common during storms. In 2022, the average U.S. home lost power for about five and a half hours, and most of these outages happen during bad weather.

The National Oceanic and Atmospheric Administration (NOAA) recorded 27 climate-related disasters in the U.S. in 2024, each resulting in around $1 billion in losses. Many of these storms caused flooding and power outages. Homes with basements, window wells or low ground are at higher risk and can benefit from having a battery-backed sump pump.

How Battery Backup Systems Work

A battery backup sump pump system sits next to your main pump. It has a 12-volt pump, a battery in a plastic box, a charger and a control panel with alarms. When water rises in the pit and lifts the float switch, the backup pump turns on and pushes water out through its own pipe. When the power comes back or the main pump works again, the backup turns off.

Some backup pumps use city water instead of a battery. These water-powered pumps use water pressure from your home’s plumbing to suck water out of the pit. They do not need electricity, but only work if you have city water and enough pressure. They also use extra water, so they are best for places where water use is not a problem and local rules allow them.

There are three important terms to know:

• Battery type: Most backups use AGM (Absorbent Glass Mat) or deep-cycle batteries. Some new models use lithium batteries, which last longer but cost more. 
• Capacity: This is the amount of energy the battery can store. It is measured in amp-hours (Ah). A bigger number means the pump can run longer.
• Flow: This refers to the amount of water the pump can move, measured in gallons per hour (gph). The higher the number, the faster it can empty your pit.

What to Look for in Backup Systems for Sump Pumps

If you are buying a battery backup sump pump, here are the most important things to check:

1. Battery Type

Most backup pumps use AGM or deep-cycle batteries, which are generally safe, do not spill and need little care. However, some newer models use lithium-ion batteries, which are lighter and last longer, but may need a special charger.

2. Battery Capacity and Runtime

The battery’s size tells you how long the pump can run. A bigger battery (like 100Ah) can run the pump longer than a smaller one (like 50Ah). Most backup pumps can move water for several hours, even during an extended power outage. 

3. Pump Power and Flow

Check how much water the pump can move. If your basement floods quickly, choose a pump with a higher flow rate. Compare gallons per hour at your head height, not just at zero feet, to ensure the pump can keep up during storms.

4. Easy to Install and Use

Look for a system with clear instructions, simple wiring and easy-to-read lights or alarms. Some systems have Wi-Fi or phone alerts, so you know if there is a problem even when you are not home. Choose kits with labeled terminals and quick-connect fittings to speed setup and cut wiring errors.

5. Cost and Value

Cheaper systems may not have as many features or use smaller batteries. More expensive systems often have better chargers, alarms and smart features. If the battery is not included, remember to add the cost. If you do not have city water, do not buy a water-powered pump.

6. Local Guidelines

Some places have rules about using water-powered pumps or backflow valves. Always check your local building codes before you buy or install a system. For example, your city may require a reduced-pressure zone (RPZ) backflow preventer and a plumbing permit for a water-powered backup, and it may ban these setups on private wells to prevent contamination.

5 Best Value Battery Backup Systems for Sump Pumps

These battery backup systems are good choices for most homes. Choose the one that best fits your home and your needs.

1. Star Water Systems STBB100 Basement Sentry Battery Backup

Star Water System’s STBB100 centers on simplicity and strong flow. The kit includes a 12-volt backup pump, alarm controller, charger and battery case. It lists a 29 gpm capacity at zero lift, with performance tapering as head height rises. The pump mounts alongside the primary in standard basins and uses a separate check valve for clean operation. 

Strengths: Straightforward wiring, compact hardware and clear status indicators. Pair it with a 100Ah deep-cycle AGM to extend runtime during long storms. Watch pit size, discharge layout and lift height to get the most from the flow.

Best Use Case: Basements with a standard 18-inch basin, typical storm loads and homeowners who want an uncomplicated backup from a recognized brand. Independent lab coverage of this specific model appears in Consumer Reports’ sump pump lineup, which adds confidence for spec-driven buyers.

2. Liberty Pumps 442-10A-EYE StormCell 12V Backup with NightEye

Liberty Pumps’ StormCell pairs an efficient DC pump with a smart charger and NightEye connectivity. The 442-10A-EYE variant includes wireless alerts for pump run time, high water and battery status. Liberty rates this system to a shut-off head of 22 feet, with strong performance in the mid-head range and about 1,830 gph around 10 feet per independent reseller specs.

Strengths: Professional-grade controller, app notifications and a proven brand from the wastewater sector. The charger manages battery health, which helps if the site sees frequent summer storms. Trade-offs include a higher up-front cost and the need to place the controller where Wi-Fi remains stable during outages.

Best Use Case: Homeowners who want real-time alerts, property managers and builders who value a monitored system.

3. Zoeller 507-0005 Basement Sentry 12V DC Backup

Zoeller’s 507 series remains a staple in backup pumping. The package includes the 12-volt DC pump, controller, float, check valve and battery case. The 507 moves water steadily at a modest head and integrates cleanly with many Zoeller primary pumps. Buyers often choose a bundled kit with a primary pump, but the 507 also drops into retrofit pits.

Strengths: Durable components and wide field use. The controller offers clear audible alerts that crews and homeowners can hear from a floor up. Watch the pit layout, as some installs need plumbing changes for a dedicated discharge.

Best Use Case: Homes that already run a Zoeller primary or projects that value extended product support and widely available parts.

4. Wayne ESP25 Battery Backup Sump Pump

Wayne’s ESP25 anchors many retrofit installs thanks to accessible parts and dependable output for midsized pits. Wayne offers detailed head curves and life cycle testing on its backup lineup, and homeowners like the brand’s clear manuals. Pair the ESP25 with a quality AGM battery and consider Wayne’s combo kits if the primary needs replacement. 

Strengths: Balanced output, field familiarity and strong support materials. Trade-offs include fewer native smart features than some competitors, unless you add separate sensors.

Best Use Case: Standard residential pits where a workhorse battery backup fits the budget and the team wants a more straightforward, proven install.

5. Basement Watchdog Special CONNECT

Basement Watchdog’s Special CONNECT moves up to 2,600 gph at zero lift and about 1,850 gph at 10 feet. The controller can connect to a Wi-Fi module or a home security dialer for alerts. The system uses dual micro-reed floats to cut false starts and includes clear maintenance prompts for battery water level on flooded-cell batteries, or it pairs with an AGM for lower upkeep. 

Strengths: Solid flow at standard head heights, accessible replacement parts and optional Wi-Fi. Watch the battery choice and charger settings to match the chemistry.

Best Use Case: Basements that take on water quickly during downpours and owners who want a smart-enabled approach without paying top tier.

Comparing Backup Systems For Sump Pumps

Use this quick table to match features to your site. Check the head height of the feet from the pit to the discharge and plan the battery size to match the storm history.

*Manufacturers and retailers list detailed head curves. Always size for your vertical lift and discharge length before buying. 

Maintenance and Longevity — Getting the Most from Your Backup System

A backup sump pump only works if it is ready when needed. Here’s how to keep it in good shape:

• Test your backup pump every month: Lift the float switch to ensure the pump turns on and the alarm sounds.
• Check the battery: Look for warning lights or alarms on the charger. Replace the battery every four to seven years, or sooner if it looks swollen or weak. 
• Keep the sump pit clean: Remove leaves, dirt or other debris from the pit and the pump’s screen. Ensure the check valve works and the water flows away from your house.
• If you have a water-powered pump, check the shut-off valves and backflow device: Some cities require a plumber to check these parts every few years.

Watch for signs of trouble, such as alarms you can’t silence, frequent cycling in dry weather or a pump that runs but does not lower water. Replace swollen or weak batteries and any water-logged float. If the site uses a water-powered unit, verify that backflow protection and shut-off valves operate smoothly. Local codes may require periodic checks of backflow devices.

Frequently Asked Questions About Battery Backup Sump Pumps

Homeowners and project teams ask similar questions while selecting and installing backup systems for sump pumps.

How long do backup batteries last?

A good AGM deep-cycle battery can last four to seven years if you keep it charged and test it often. During a power outage, a fully charged battery can run the pump for several hours, or even days if the pump only runs sometimes.

Can I install a backup sump pump myself?

Yes, many people can install a battery backup with basic tools and by following the instructions. If you are unsure or need to add a water-powered pump, you may want to hire a plumber — especially if your city has special rules.

What battery size do I need?

Per common guidance, start with a 75Ah-120Ah deep-cycle battery, then increase capacity when your lift and inflow are higher than average.

What if both the main pump and the backup fail?

Most systems have a loud alarm to warn you if the water gets too high. You can also add a Wi-Fi alarm or a sensor that sends alerts to your phone. In flood-prone areas, some people add a second backup or use both a battery and a water-powered pump for extra safety.

Notes on Batteries, Flow and Value

Battery-powered backups dominate the market because they fit most sump pits and budgets. They typically use a 12-volt deep-cycle battery similar to those in trolling boats or golf carts.

Battery capacity — measured in amp-hours — tells you how long a pump can run between charges. Systems in the 75Ah-120Ah range handle several hours of active pumping, often across several days of intermittent cycles. Most models move about 800 gph-2,000 gph, depending on lift, which fits storm loads in many neighborhoods. 

Staying Dry With a Reliable Battery Backup System

Choose a battery backup sump pump as the first defense against basement floods. Size the battery by amp-hours to match head height and expected inflow, add audible or Wi-Fi alerts and schedule a quick monthly test. Replace the battery regularly and clear the pit so the backup fires immediately. Keep water moving when the power drops. Stay safe and dry!

Related Posts:

• How to Protect Your Foundation from Water Damage
• From Backup Power to Grid Flexibility: Exploring the Versatile Functions of Battery Storage
• How Diesel Generators Support Critical Infrastructure During Outages
• Electric Vehicles: The Future of Transportation