The Best Battery Backup Sump Pump [2021 Product Reviews]

Written by Regina Cal
Published on August 16, 2019

Last Updated on June 8, 2021

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Sump pumps are a must-have if you have a basement that is prone to flooding, or is lower than the natural water table.

Sure, we all know this! But what happens if the power goes out? As with any pump, your sump pump needs electricity to run.

Being that sump pumps work their hardest through storms, it can also be their ultimate weakness as the power is more likely to go out in a storm.

Once the sump pump goes out, there is nothing to stop the imminent rising of the water in your basement and can cause catastrophic damage to your home.

Your sump pump is your last line of defense against rising waters.

So how to circumvent this problem? Get a battery backup sump pump, of course!

In this guide, I am going to cover the best battery backup sump pump on the market and then go through everything you need to know about battery backup sump pumps.

Let's get started!

Watch the Video Version of this article!

Part One: Backup Battery Sump Pump Reviews

Best Overall:

Wayne ESP25 Upgraded 12-Volt Battery Backup System

wayne esp25 backup sump pump

Pros and Cons


  • Very easy installation
  • Comes with a nice LED screen
  • Reliable and durable unit


  • Cannot control volume level of the alarm
  • Unusual float switch design
  • Non adjustable 20 second runtime

The Wayne battery backup sump pump has the best ratings and is the most popular backup system available on the market.

Users report that it works as it should and has saved many from flooded basements.

The pump can handle 2900 gallons per hour which is quite a bit and should be able to handle most flooding events.

If used with the appropriate deep cycle marine battery, this unit can pump out 10,000 gallons of water on a full charge.

As with any product, there are drawbacks.

There is no volume control for the alarm and it is very LOUD. This can get quite annoying over time but can be remedied with a little DIY tissue stuffing. Just don't plug the microphone hole too deeply or it will break.

The float switch is a little strange; the float is on a tether system that glides up and down a rod. This in itself isn't necessarily a drawback, but the pump runs in 20-second increments and the float does not offer up enough space to possibly cover those 20 seconds of runtime. Therefore the float needs to be set high enough so the pump doesn't run dry.

Overall, based upon my research and user feedback, this is the best battery backup sump pump available on the market today.

Runner Up:

Zoeller Aquanot 508 Battery Backup Sump Pump

Zoeller battery backup sump pump

Pros and Cons


  • Battery charging is a true float charger increasing battery life
  • Sturdy heavy pump built to last
  • Extremely quiet while running


  • Screen is rather basic and can fade over time
  • Shoddy packaging; inspect unit once received
  • Power leads are a bit short

Zoeller makes some of the best pumps on the market and this backup pump does not fall short by any means! The Zoeller Aquanot 508 battery backup sump pump comes in at a close second behind Wayne.

The pump comes with a built-in alarm and lights so you know that it's kicked on.

The installation is not as easy as the Wayne system but the instruction manual is pretty direct so you shouldn't have any problems. You will need some basic plumbing tools.

When you receive this unit, make sure to check all the components as there have been complaints of shoddy packaging.

The LCD screen does seem to wear out over time and gets dim but the indicator lights telling if the system is functional seem to last so it shouldn't be too much of a problem.

The power leads are a bit short making for a tight fit but it's doable.

The price is on the higher end for the system, but not by much.

Overall, this pump gets high accolades from its users and the brand is known for high-quality pumps.

The unit does not come with a battery; make sure to purchase a deep cycle battery of at least 100 amps.

Best Buy:

Superior 92900 12V Battery Backup Sump Pump

superior backup sump pump

Pros and Cons


  • Can move up to 1380 gallons per hour
  • Made out of rust resistant thermoplastic
  • Small lightweight pump can fit into tight spaces


  • Cheap pump - you get what you pay for
  • Loud alarm does not reset when power goes back on
  • Charge cable to the battery box is easy to dislodge

Superior pumps are a very popular brand as they deliver a pretty decent quality for their super cheap price.

The casing is made of thermoplastic which helps protect against rusting which is a typical problem for sump pumps.

This pump is known for its small and lightweight design weighing in only at 12 pounds.

It can move a substantial amount of water for how compact and light it is.

Be forewarned: the alarm does not shut off when the power comes back on! You will have to manually reset it every time.

If your power flickers on and off or you are away from home, this may not be the right pump for you.

Although many users have had a great experience with this battery backup sump pump system, there are quite a few who've had faulty units or units that just don't last.

I would say it is hit or miss.

If you are on a budget and don't mind taking a chance, then the Superior battery backup sump pump could be the right setup for you.

Part Two: Information About Battery Backup Sump Pump Systems

Is a battery backup sump pump worth it?

In general, yes, it is worth spending the money on a battery backup sump pump if you rely on a sump pump in your everyday life.

Sump pumps rely on power to work, and if your sump pump loses power, then you are up the creek without a paddle. If there is a situation out there where power is unlimited and is never threatened of being cut off, then you could probably live without a backup. At this moment, I don't think such a reliable energy source exists.

Perhaps if you are in an off-grid situation and rely on your own power, then a battery backup may not be necessary unless you completely exhaust your own energy storage.

I honestly cannot think of any other situation that wouldn't require a backup sump pump. If you can think of one, please leave a comment below!

How does a sump pump battery backup work?

In a typical sump pump installation, a sump pump is placed into a sump pit located in the basement.

The pump is triggered to turn on from either a pressure sensor or a floating valve.

If the electricity is cut off, the pump goes completely dead and places your home at risk of flooding.

The battery backup sump pump has an additional pump installed on a battery system that works just like your primary sump pump.

The pump gets triggered to run by a float or tether valve rising from increasing water levels. Typically, the backup sump pump is placed higher than your original pump.

The additional water pump will turn on even if your original pump is running but gets inundated with too much water.

It is important to note that the battery backup pump will only pump for a certain amount of time; you will need to check the number of gallons it will pump per the life of the battery.

The battery gets a trickle charge from being plugged into an outlet, so it will always be full and ready to provide power in an emergency.

Battery backup sump pumps come with an alarm installed to notify you that it has been triggered. Smart battery backup systems will send you a notification to your phone.

How long does a battery backup sump pump last?

Battery backup sump pumps provide how many gallons of water will be removed off of one battery charge, but does not specifically state how many hours it will last.

In order to figure out how long your backup sump pump will last, you will need to do a bit of reverse engineering.

For example, the Wayne ESP25 backup pump will pump 10,000 gallons off of one charge. We can assume that this pump rate is figured at 0 head.

The documentation states that the pump will discharge 2,900 gallons at 0 head.

Therefore, the pump will run for roughly 3 1/3 hours.

However, this is not an exact measurement. You can get an exact measurement if you can find the amps of the pump. I personally could not find the amps of the Wayne ESP25 in the manual.

If you can find the amp hours of the pump, simply divide the amp hours that your battery will hold (75 amp-hours for Wayne) by the amp-hour of the pump and that will tell you how long the pump will run per battery charge.

How much does a sump pump battery backup cost?

You can expect an expensive battery backup sump pump to range in the upper $300 range.

A middle-of-the-road pump is in between $200-$300.

The cheapest pumps are at about the $150 range.

Before you jump on the cheapest backup out there, realize that you are paying half for the most expensive ones on the market. Some things you can buy cheap, but these are not one of those things. I suggest going with a more expensive, yet more reliable setup.

How to add battery backup for existing sump pump

It is possible to add a backup battery system to an existing pump.

Unfortunately, no, you cannot just rig your current sump pump with a car battery and hope for the best. If you do figure out a way to make a DIY backup, please let me know!

From what I have researched, the only available current option is to purchase the Pump Sentry.

The Pump Sentry is a wall-mounted battery backup system that is designed specifically for turning on your sump pump in times of a power outage.

The unit plugs into an AC outlet and trickle charges the connected battery. The unit has a sensor that tells the power has been cut off and triggers the battery to release its power to the sump pump.

When the power comes back on, the unit switches the power off from the battery and back to the outlet.

There are some drawbacks to the Pump Sentry:

1. Although the peace of mind to have backup power to your sump pump is nice, it is still only one pump. If the pump gets overwhelmed with water it won't matter how much power is running to it - your flooded out.

2. The unit costs close to twice as much as purchasing a battery backup system! And it doesn't come with a deep cycle marine battery which is also very expensive.

Overall, the response has been great from homeowners, saving many people's basements from flooding. This can make it worth the additional expense if you don't mind spending the money and don't want a secondary pump.
If you want it, you can get it from Amazon.

Pump Sentry

Battery Backup Sump Pump vs Water Powered Sump Pump

It would appear that a water powered sump pump would be the top choice for a backup sump pump system. After all, it does not use electricity to run so can never fail due to power outages or empty batteries.

There are drawbacks to both pumps, so weigh your options carefully before committing to either.

Water Powered Sump Pump

Pros of a water powered sump pump

  1. It requires no electricity to run. You won't have to worry about power outages or depleted batteries.
  2.  Unlimited running time with no maintenance needed.
  3. No worries on having to replace or maintain a battery backup.
  4. These units hardly ever breakdown or need to be replaced.

Cons of a water powered sump pump

  1. Water powered sump pumps have to be connected to a water line in order to work as it needs water to run.
  2. For every 2 gallons of sump water removed, 1 gallon of city water is needed which can get very expensive. Some municipalities have actually banned these types of pumps in times of drought.
  3. Installing can be complex as it requires a whole new water line, backflow preventer, and a drain line to reduce chances of contamination.

Pros of a battery backup sump pump

  1.  Installation of the battery system is very simple.
  2. As long as you have a fully charged battery, you can get up to 10,000 gallons pumped away. You may also get an AC/DC model which trickle charges your battery.
  3.  The secondary pump can act as an assist if your primary pump gets inundated with water.

Cons of a battery backup sump pump

  1. If the power is out for too long and your battery is depleted, your backup system is dead in the water (no pun intended!).
  2. Batteries require maintenance, routine monitoring, and replacement every five years or so, according to manufacturer's directions.

I would say that the better choice for a backup sump pump would have to be the battery powered pump. The installation process of a water powered pump is rather daunting and can be quite expensive. I also don't like the idea of contamination of the existing water system.

A water powered pump might be a good option for new home builds when the pump can be installed much easier and more affordably.

Bottom Line

A battery backup sump pump is an essential unit to have to ensure that your home won't flood out during times of power outages.

However, they are not a silver bullet and do have some drawbacks.

Prepare to replace batteries, maintain, and monitor them to keep up maximum performance.

Your backup system will only run as long as your battery is charged so it's not an end all be all solution.

However, it is more reasonable and affordable to install than a water powered backup pump.

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  • Thank you for this post. can’t say I know aa lot about the sump pump, but my sump pump is not working properly I think. The basement is flooded and the alarm didn’t go off. I don’t know what the problem was. the pump should drain the water automatically, shouldn’t it? I don’t know much, But I guess I will change the battery.

    • My first guess is that the float switch is not working. There should be a float that rises with the water level. Its attached to a little arm. If that float switch did not rise, the pump would not turn on. I would check that out first as its a pretty easy fix.

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