Best Battery Backup For Existing Sump Pump In 2022

Since basements are below ground level, they’re usually prone to floods if water accumulates. For that reason, homeowners build a sump pit in the basement and install a sump pump to protect the basement from these unfortunate events.

Most sump pump systems are powered by electricity so that the pump kicks in as soon as there’s water in the sump basin. The problem issue with that is in cases of power outages, which are common during floods and storms, the system can stop working at the worst possible moment.

This is where a battery backup system comes in handy. Battery systems act as a backup plan to protect your house by taking over whenever the electricity stops working. Now the clear question is, what is the best battery backup for a sump pump?

This guide covers seven of the top battery backups for your existing sump pump, as well as other things you need to consider.

Top 7 Battery Backups For Existing Sump Pumps

1. Zoeller Aquanot 508 Battery Backup System

Zoeller Aquanot 508 is easily one of the best battery backups you can buy. This fully-automatic 12-volt system can pump up to 2,100 GPH at 10 feet.

The battery backup pump can also run for over 6 hours on a full charge. Moreover, the system can send you a notification when it needs extra help. 

The corrosion-resistant aluminum pump features integrated check valves with self-testing technology and a quick-disconnect system to save battery. 

The system comes fully assembled and ready for instant installation with all the parts it needs, so you don’t have to worry about buying anything separately. 

Although it is a bit pricey, it’s one of the top options at its price range and is an excellent bang for your buck.

2. Wayne ESP25 Upgraded Battery Backup System

Wayne ESP25 packs a punch in terms of power and durability, making it one of the most reliable backup batteries for basement sump pumps. It’s also affordable, which adds to the value of the product.

The Wayne ESP25 has a cast-iron bottom and a steel housing fully coated with epoxy for protection against excessive moisture.

The backup system has an excellent capacity of about 1,680 GPH at 10 ft and 2,900 at 0 ft, making it one of the most powerful in its price range.

Additionally, the battery allows the backup system to last for up to 26 hours with a cycle of 5 gallons every minute!

In addition to all that, the backup system comes with all the modern features for safety, such as alarm sounds, LED readout, and an intelligent charging system.

3. THE BASEMENT WATCHDOG CITS-50 Sump Pump Battery Backup System

If you want a complete sump pump system that comes with its own battery backup, you should consider the CITS-50.

This advanced system has a primary pump with a capacity of 3,450 GPH at 10 ft and a backup pump capacity of 1,850 GPH at the same height. This makes it perfect for homes that need a backup system with a little more power while cycling water.

The battery backup sump pump has quad float switches with automatic charging for added protection and comes pre-assembled for easy and non-costly installation. A quality float switch helps you avoid the common issue of them getting jammed causing your pump to start and stop every half a minute or so.

If you want to get rid of your old sump pump and install a completely new one, this one is a good choice.

4. THE BASEMENT WATCHDOG BWE Sump Pump Battery Backup

If you’re on a strict budget and looking for the most affordable option out there that can function decently, the Basement Watchdog has you covered.

The BWE model is an inexpensive solution that has a cycle capacity of around 1,000 GPH at 10 ft, which is more than enough if your area rarely gets flooded with water.

The backup system is compatible with various batteries, including AGM and wet batteries.

The system comes with audible alarms and a simple controller monitor to let you know the current status of the system. The system also comes with dual float switches, which give you twice the protection against floods.

5. Sec America Pump Sentry 822 PS Emergency Power for Sump Pumps

If you don’t mind spending a little more on an emergency system that will keep your existing sump pump system alive through a power failure, you should consider the Pump Sentry 822 PS from Sec America.

Unlike other options on the list, this sump pump powers up the system itself using the primary pump instead of utilizing a secondary pump.

As long as the electricity is running, this new battery backup charges up and monitors the wall outlet for power. But as soon as the electricity cuts off, this system overtakes the responsibility for powering up the existing sump pump with a capacity of up to 1,200 watts. 

When the electricity is back on, the system automatically switches back to AC current directly from the wall. 

As you can see, such a system is ideal for those with robust and reliable existing sump pumps and only need a battery-powered system to keep it up during outages.

6. THE BASEMENT WATCHDOG BWSP Sump Pump Battery Backup System

This is another sump pump battery backups from the Basement Watchdog, which shows the level of quality and variety they offer in their products!

This model is considered a nice middle ground between the two previously mentioned models of the same brand.

It offers a standard capacity of 2,600 GPH at 0 ft and 1,850 GPH at 10 ft, which is an upgrade from the old BWSB model that had 1,730 GPH at 10 ft.

The system also features dual float switches, similar to the one in the BWE model but not as high as the quad system of the CITS-50.

However, the system here has the edge over the BWE model by offering a remote notifications feature through a WiFi connection to alert you through email, text, or directly through the app.

7. PumpSpy PS2000 Battery Backup Sump Pump System

The PumpSpy PS2000 is an excellent pick for those who want a powerhouse to keep up with a high-end existing sump pump (0.5 HP or higher).

This helpful device features a 12-volt marine-grade system that can pump up to 2,400 GPH at 10 ft. This makes up for the relatively short runtime of 5.5 hours on continuous operation on a single charge.

The system also uses WiFi to send notifications to your phone about the status of the pump, along with free monitoring without any subscription fees.

In addition to taking over in the case of a power outage, it’ll also let you know about the situation and current status, which is super handy when you’re far away from home.

The system can also check itself once every 48 hours to ensure that it’s operating without errors. 

Battery Backup for Existing Sump Pump Buying Guide

Since battery backups for existing sump pumps don’t come cheaply and are considered a long-term investment, you should always pay extra attention to some of the critical features and aspects that set them apart.

To make the choice-making process more streamlined for you, here is a list of all the essential points and features you should consider.

Simple Battery Backup Vs. Full System with Extra Backup

When choosing a battery backup for an existing sump pump, you want to keep the type in mind to avoid running into compatibility issues. You should also keep in mind that some battery backups don’t have a backup pump.

Instead, they’re only a backup battery hooked to the primary pump or use a current inverter to turn the DC power into AC power to run the existing system.

If you already have a current sump pump, you should consider a standalone battery backup to support it. 

However, if you don’t have a primary sump pump, you should get a full system that has a sump pump with an extra battery backup for easier installation and a reduced package cost.

Construction and Durability

The build quality of the sump back battery backup is quite essential and should always be a priority.

The quality of materials here extends beyond the battery backup and includes all the accessories and extra parts, such as the converters.

Always make sure the battery backup system is made from corrosion-resistant materials. The system housing should be sealed professionally to prevent any moisture from finding its way into the internal components of the pump, inverter, or battery.

The top materials here are stainless steel, thermoplastics, aluminum, and paint-coated cast iron because, besides corrosion resistance, these materials are robust and prevent dust accumulation.

In addition to the materials, the design of the system should also promote functionality. For instance, the system’s housing should also facilitate an efficient heat transfer to keep the battery and the inverter cool and prevent overheating problems.

Capacity and Performance

The performance of a battery backup is one of the major determiners of its quality. The main aspect of performance in a sump pump system, whether it’s a primary or a backup one, is the capacity.

The capacity of a pump is usually measured at gallons per hour of GPH, which translates to the maximum amount of water gallons the pump can push out within an hour if the battery was fully charged when it started.

Ideally, most backup sump pumps out there will have two capacity ratings at two different heights. 

For example, an average pump should be around 1,000 to 2,000 GPH at 10 ft and 2,000 to 3,000 GPH at 0 ft.

This should be enough capacity to push the water from the basement level to the ground level, where the water can be drained into sewers. 

Luckily, most backup systems out there will clearly state their capacity and power on the label, so you won’t have a hard time picking a battery backup that offers power that meets the needs of your existing sump pump system.


Since we’re discussing a battery-based system here, the runtime, battery power, and battery life are significant factors while picking a winner.

Ideally, a battery system will run on acid-free 12-volt batteries, which typically have a backup power that ranges from as low as 40 amp hours but can go as high as 120 amp-hours. 

The runtime determines the amount of time that a fully charged battery can push the water coming into the sump pit. The higher the amp-hour rating of a battery, the more powerful and longer runtime it’ll offer.

The most commonly used battery power out there is 75 amp-hours, which offers the highest value when it comes to price per performance and runtime. 

At such an amp-hour rating, the battery can for about 50 to 60 hours and pump out 2 gallons with each cycle — provided that it cycles every 4 to 5 minutes.

In addition to picking the one that suits your requirements, the best practice here is to look for marine-grade batteries because these are built to withstand moisture much better than a standard one. 

Also, look for a high-efficiency pump battery capable of operating for longer without overheating and wasting energy.

Ease of Installation

Depending on your level of expertise, you may or may not need a plumber to install the system for you. 

Technically, to install a battery backup system, you need a combination unit that connects the new batteries with the existing system. 

Alternatively, you might need to simply fit the battery backup system next to the existing pump while ensuring that extra items are in place, such as inverters. 

Even if you’re not installing the system yourself due to license requirements of local laws, getting a simpler system means shorter installation time, and therefore, fewer labor costs.

Extra Features

In the case that you needed a battery backup for your existing sump pump, it would be wiser if the system that you’ve installed is prepared for all kinds of scenarios that could happen in such an emergency.

For example, a good battery backup system for existing sump pumps can also include some automatic chargers, indicators, or even WiFi alarms that can send you notifications about any mishaps or problems down there for early intervention. Time can be the difference between hundreds and thousands of dollars in water damage costs. 

Why You Need A Battery Backup

Now that you know more about sump pumps, you might still be wondering whether it’s worth it to get a battery backup system in addition to your existing sump pump. Here are some of the major advantages of having one on your property:

It saves you thousands of dollars worth of water damage repairs. Spending some money to buy a good backup battery for extra protection in sump pumps in the basement or crawlspace can be a considerable investment to avoid expensive water damage repairs. 

In fact, a typical basement can cost you anywhere from $3,000 to $10,000 to repair if it gets a minor flood with several inches of water.

However, the costs of repairs can substantially increase depending on the level of severity and the size of your basement. This doesn’t include the damages inflicted on an expensive machine that is left down there, like washing machines and dryers.

A battery back sump pumps continuously pump through a power outage. A primary sump pump uses house electricity to run. However, a powerful storm can shut down electricity lines, leading to power outages. Other times, a sump pump might come out faulty leading it to constantly run without stopping, which can eventually cause it to break.

If the electric power in the property is lost, any accumulation of water in the basement can turn into a flood. 

However, with a battery backup system, you’ll enjoy the peace of mind knowing that even if the main electricity lines shut down, your main sump pump will push out the water efficiently.

They add an extra layer of security against existing pump failure. Some people might install multiple sump pumps in their basement for fear that the existing pump might fail at any moment. 

However, having a battery backup system will save you the hassle of multiple installations and add a layer of security to the existing sump pump at a reduced price.

Some modern systems even come with a notification system that can communicate with your smartphone to warn you of any potential flooding in the basement.

Some systems can also help the existing sump pump in your basement. If the pump is still operating, but with sub-par performance, some systems are designed so that it’s triggered at a certain point to help the pump with the pushing, extending its lifespan. A battery backup doesn’t just work during a failure, but it also acts as a helping hand.

About the author 

Ken Jenkins is a Master Plumber at Roto-Rooter Indianapolis. Passionate about all things plumbing, Ken is eager to share his knowledge of pipes and plumbing systems with the world. Ken and his fellow Roto-Rooter plumbers are available 24/7 to resolve any plumbing or drain issues. Schedule a consulting and service appointment with them.