Informational Guide

Can You Add Battery Backup To Existing Sump Pump? (How-To)

by Andrew

Your sump pump helps protect your home by removing water from the lowest parts of your home. This stops water from pooling, damaging your home and possessions, and even causing mold to spread throughout your home.  

It is usually connected to your mains electricity supply, and it's important that it's able to run continuously or your home is unprotected.

In this guide, we'll explain whether you can add a battery backup to an existing sump pump and what the key benefits are.  

Almost every single sump pump can have a battery backup added to it, even if it wasn’t designed with one already included. 

In fact, many homeowners are choosing to add battery backups to their sump pump because of the benefits they offer: 

Protection Against Power Outages 

Power outages happen more frequently than you think, disrupting your sump pumps operation. If your power goes out, then your battery backup will kick in and keep it running until you can get the power going again. This means there are no gaps in protection for your home.  

Protection Against Tripped Circuit 

Your circuit trips as a precaution against unexpected surges. This helps to protect your home from electrical fires and prevent damage to your appliances. It can take you a while to notice it's happened, but your sump pump won't have access to any power at that time. A battery backup will provide protection to cover these periods until you can reset the breaker and get power flowing again.  

Protection Against Sump Pump Failure 

If your sump pump becomes clogged or starts to fail, then the power can cut out. A battery backup will give an alternative power source to get it running again so it can keep removing water from your home.  

Extra Protection During Extreme Weather 

Unfortunately, power outages can often happen during periods of extreme weather, and this is where you need your sump pump the most. A battery backup will keep your pump running during these extreme conditions and keep floodwater out of your home. 

Sump Pump

4 Factors To Consider When Installing A Battery Backup  

There are many different battery backups to choose from, and it can be challenging to know where to start. These are the key factors to consider which may help you narrow down the choices: 

1. Alarm System 

Part of the reason battery backup systems are so important is because you don't always notice that the sump pump has stopped working. Backups with built-in alarm systems will notify you when they kick in. This will let you know something is wrong and you need to take action, so it's definitely a feature to look out for.  

2. Pump Capacity 

Your pump capacity is the amount of water it can pump from your home in a given period. This is generally measured in gallons per minute or gallons per hour and gives you an idea of how much they can handle. If your battery backup kicks in, then it needs to be able to provide the same amount of power so that the pump can keep working at the same pace. Look for a pump that offers the same gallons per hour so it will run properly.  

3. Self-Test Feature 

Your sump pump needs to run pretty frequently to keep it in working order. Some battery backups come with an automatic test feature which means they'll periodically switch on to test themselves. This activates your sump pump and keeps it running as it should, so it's a useful feature for a backup to have.  

4. Battery Capacity 

You should consider how often your sump pump runs and how much power you might need. The battery capacity is how long it will be able to run, and you need to pick a battery with enough capacity, or your pump will cut out before you can get the primary power source back on.  

Battery Type  

There are a few different types of battery backups, but you should always opt for a marine battery (sometimes called a deep-cycle lead-acid battery). The output from this type of backup is measured in amps per hour and will give you a clear rating of how long it will run.  

How To Add Battery Backup To Existing Sump Pump (DIY Install) 

It’s really easy to install a battery backup to your existing sump pump, and you don’t need much electrical experience. It’s really important that you turn off the power to the sump pump completely to avoid any risk of injury, and if at any point you feel unsure, you should consult a professional.  

Before starting, you should make sure you have your new battery backup pack and some wire cutters because you may need to trim back some wires to connect them to your pump.  

  • 1
    Mount The Battery Pack 
    Your battery backup should come in a plastic box to protect it from any moisture. This box needs to be mounted on a wall less than 4 feet away from the pump and close enough to reach the sump pump electrical cable. You should be able to screw the box directly into the wall without much hassle. 
  • 2
    Make The Connections 
    This is the only slightly tricky part of the process, but even without electrical experience, you should be able to do it. Make sure the pump is turned off on the machine and at the circuit. Then, locate and take the red cable from the battery pack and connect it to the positive terminal on the sump pump. Next, take the black cable from the battery pack and connect it to the negative terminal. The location of the sump pump terminals and the color of the battery cables may vary. Make sure you check the user manual and specifications so you can connect everything up correctly.  
  • 3
    Test The Battery 
    Make sure your sump pump is plugged in, turned on, and running properly (there is usually an LED light to indicate it's turned on). Next, unplug the pump and watch to see if the LED light stays on. If it does, it means that the battery has kicked in and your backup power source is working. Once you're sure it's working, plug the sump pump back in so it can run from the mains. Your battery backup should now be in place.  
covering sump pump

What Is The Best Battery Backup For My Sump Pump? (+ Where To Buy Them) 

You can buy sump pump battery backups fairly easily online, and there's plenty to choose from. You’ll typically pay $200-$600 for a battery backup, but you can find some cheaper models if you have a tight budget. AmazonLowesMenards, and Home Depot all offer some good quality backups and we'd encourage you to start looking there. Here are 3 of our top battery backups to get you started: 

  • The Basement Watchdog (Amazon) 
    This battery backup is great value and costs less than $200. Considering its low cost, it offers a good amount of power and can support pumping of over 1000 gallons per hour. We found it really simple to install, and it can run for over a day continuously. This isn't the most impressive battery backup around, but it offers some outstanding value.   
  • Zoeller Battery Backup (Lowes) 
    Zoeller is a well-known brand for sump pumps and manufactures some of the most popular models on the market. It can support pumping of over 100 gallons per minute and is well suited for powerful sump pumps that see a lot of use. This battery backup will last for days and automatically charge when the pump is plugged into the mains. It’s one of the more expensive backups at $600 but should give you absolute peace of mind that your pump will keep running.  
  • FVP Volt Edge Backup (Menards) 
    Menards offers a cheaper alternative battery backup at under $250. It has enough power to pump 7500 gallons of water on a full charge, which is plenty for most homes and will support any small or medium-sized sump pumps. In addition, it's designed to have a long life and integrates easily with all major sump pump brands, so installation is simple.  


How long does a sump pump battery last? 

Every sump pump is different, but most will be able to power your sump pump running continuously for 5-7 hours. You will get some batteries that offer more power and last longer.  

How much does it cost to install a sump pump battery backup?  

If you want to hire a professional to install your battery backup, it will probably cost $100-$200, depending on the area you live in and the type of sump pump you have. 

What size battery backup do I need for a sump pump? 

The battery needs to be able to power your sump pump, so make sure you have enough amps. As a rule, you should look for a sump pump battery backup with at least 75 amps.  

How often should you replace a sump pump battery? 

Your sump pump backup battery should be replaced every 5 years but may need to be replaced more frequently if it sees more use.  


Your sump pump needs to be able to run whenever it’s needed, and installing a battery backup to the device is a great way to ensure that happens.  

Hopefully, this guide has helped explain the key benefits of a battery backup and how you can install one yourself without any professional help. Remember, electrics can be difficult and dangerous, so if you aren't sure, then you should consult a professional straight away.