Best Battery Backup For Existing Sump Pump

Last updated on December 30th, 2021 | By: Grady Galvez


When the snow thaws, it is usually a welcoming sign for most homeowners but that is only, if the process happens smoothly. The extra pressure of the snow and rain may put pressure on your sump pump. But what if your power supply fails??

While searching for an alternative for water restoration in case of power failure, many would suggest a sump pump with battery backup, but wait, adding a battery to your existing sump pump could be a better option. Getting the whole new unit is costly while it renders your existing sump pump out of operation.

It ain’t that tricky to add a sump pump backup power, the battery could be mounted on a wall and provide power to your pump. I explain a simple step by step procedure to connect a battery or a UPS to your sump pump. Also reviewed below, the best sump pump batteries in case you chose to attach one yourself.

Best Sump Pump Battery - A Quick Glimpse

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Why These Batteries Stack Up Against The Competition?

★ Best Overall ★

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1. Interstate Batteries SLA/AGM Deep-Cycle Battery

The DCM0100 is rechargeable, and maintenance-free. The DCM battery line was specifically designed for scooters and wheelchairs, remains the top-performer for heavy-demand mobility applications.

You can power your performance with the perfect choice in rechargeable Sealed Lead Acid (SLA) batteries for your business applications. If you use an Interstate battery then you are not harming the environment in any way and this really gives you peace of mind.

The technology used to create this battery, prevents spilling, over-pressurization, and remains useful with a long life-span for deep-discharge uses. See a list of great offers here. The fit-type of the battery is universal and it works with 12V 100ah battery applications.

Overall these batteries are of pro-grade quality, work constantly, and give long-lasting performance for many application types, the battery which is made using the VRLA (valve regulated) Technology, also check out whether it comes with studs or not.


  • Deep-cycle mobility product.

  • Uses AGM and VRLA Technology.

  • Professional-grade quality product.

  • Maintenance-free & spill-proof.

  • Dimensions- 12.99L x 6.81W x 8.35H (in inches).

  • Suitable for numerous applications.

  • Eco-friendly battery.


  • Not a replacement for golf cart batteries.

     ★ Best Budget ★     

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2. Weize 12V 75AH Deep Cycle Battery

The Weize 12 V battery delivers power when you need it the most. Created with the state-of-the-art technology, this heavy-duty battery along with its calcium-alloy grid construction offers extraordinary performance and an unmatchable service life in float and cyclic applications alike.

The deep cycle battery is made with the AGM (Absorbent Glass Mat) technology, with a valve-regulated design which can be used in indoor and enclosed environments both. This stays leak-proof and maintenance-free offering top-level performance for numerous models. Just check out the real user reviews for a second opinion.

The SLA batteries are used in varied applications such as emergency lighting, medical mobility, portable tools, golf carts, lawn and garden tools, toys and hobby, and more.


  • Delivers power when you need.

  • The FP12750 is made with AGM technology.

  • Can be used in enclosed and indoor environments alike.

  • Comes with a 30-day refund policy.

  • Suitable for many applications.


  • Users just love it.

  • No downsides as such.

     ★ Premium Choice ★      

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3. Wayne WSB1275 75Ah Maintenance-Free Battery

A brand that promises innovation with quality service. This is a pre-charged 12V battery which shows compatibility with all Wayne Battery backup systems.

The battery comes sealed and there are no worries of any injury as you do not have to face any battery acid mixing. The WSB1275 comes powerful and supports 8-hours of sustained pumping power with protection of 11,000 gallons in the high-grade basement protection systems.

Just unbox it and it is ready to use as this comes pre-charged. Comprises of carry handles that are quite convenient for the user, here is its full setup video.


  • Compatible with all Wayne battery back-up products.

  • Sealed lead acid battery (no handling acid).

  • Pre-charged and ready to use.

  • 12 volt, 75 amp hour.

  • Carry handles for convenience.


  • A bit higher priced than the others, though worth every penny spent.

  • Lasts longer which users appreciate, no drawbacks of the product.

     ★ All Time Great ★      

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4. THE Basement Watchdog Sump Pump Battery

The Basement Watchdog is a battery that comes completely sealed, and serves as an ideal choice for battery backup sump pump systems. You need not add any battery fluid or distilled water and this also gives you reliable service for years.

The compatibility feature of the battery makes it suitable for mostly all Basement Watchdog systems. For ensuring the product compatibility just look at the ‘+’ on its upper left-hand corner before you invest in it. Click to know more about its compatibility feature.

This runs various Basement Watchdog lightweight sump pump systems intermittently for days. This gives you many hours of hassle-free performance:

  • Up to 40-hour protection (based on a 10% duty cycle) on the Basement Watchdog Big Dog (BWD12-120C+).

  • Up to 48-hour protection (based on a 10% duty cycle) on the Basement Watchdog Special + (BWSP+) and Basement Watchdog Big Combination sump pump system (BW4000).

  • Up to 80-hour protection (based on a 10% duty cycle) on the Basement Watchdog Emergency (BWE) and Basement Watchdog Combination sump pump system (DFK961).


  • Maintenance-free battery.

  • Compatible with most Basement Watchdog Systems.

  • Offers reliable service for years.

  • Two batteries can be connected to increase the run time.

  • Comes with a 1-year free replacement guarantee.


  • Cannot be returned online in case of any defects but the manufacturer can always be contacted.

     ★ Runner-up ★      

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5. Zoeller Wet Cell Battery

The Zoeller 10-0761 is a wet cell battery with a Pro eye indicator that helps to maintain water and acid level. The battery requires monthly maintenance though it is pretty simple to care for it.

The battery keeps you stress-free as it offers a continuous run time of 5 to 7 hours for a DC back-up system. The product comes with a one year warranty and has convenient dimensions: 6.5″ H x 13″ W x 9″ D.

Along with the pro eye indicator quality we really appreciate one more thing that this battery works with all types of battery backup sump pump systems. Even you can easily see when there is a need to add water in the battery.


  • Pro eye indicator helps to maintain water / acid level.

  • Works with all types of battery backup sump pump systems.

  • 83 Amp Hours (200 Minute Reserve Capacity).

  • Provides 5-7 hours of continuous run time for DC backup systems.

  • Can check with ease when water needs to be added.


  • Water needs to be added when required.

How We Rated the Sump Pump Backup Batteries


Irrespective of the above-mentioned batteries reviewed for Sump Pump Batteries, the below-mentioned points must be an explored before making a purchase so that you don’t despair later

Battery Backup Sump Pump


Water or battery-powered sump pumps can reach up to 2000 cycles on a fully charged 12V/75Amps battery and can provide for approximately 5 to 6 hours continuous operation. These types of sump pumps can work automatically without being turned off or for up to 2 days.


The size of the sump or the basement remains the prime factor along with the existing sump pump power which ultimately requires to be powered. Sump pump batteries are available up to 5000 Watts which can generate a peak load in case of power failure. Most Sump Pump used in residential properties has up to 1 HP Power.

So a standard 12 V battery is enough to power them up. In case of limited space in your basement sump, you can go for a pump with battery backup.


AGM (Absorbent Glass Mat) batteries are the most desirable batteries to consider if you’re working with the latest sump pump batteries. Other alternatives like Wet Cell and Marine batteries require a contact handling for checkups and are also prone to exploding. While the AGM batteries are completely maintenance-free and are quite long-lasting without requiring any constant attention.


In case of back-to-back outages, these pumps are highly effective but one must pay attention to the voltage to make sure that the battery is charged in time and doesn’t take too long. Many people also install a solar panel to charge the backup battery, though it’s a costly arrangement but are highly effective, easy to main and cost-effective in the long run.

Here Are 3 Sump Pump Backup Options To Consider

Fortunately, there are different options available which you can use to keep your sump pump problem under control.

There are two types of battery back -up systems available –DC and AC/DC. These battery back-up systems switch to DC power as soon as the AC power is cut off.

However when AC is on your pump functions as normal. Apart from that, you should also consider which kind of battery you would want to incorporate.

Sump Pump

You will find deep cycle maintenance free batteries as a great alternative. The batteries would be a water powered sump pump battery that need water at regular intervals that you must keep adding.

Sump Pump Inverters Or UPS For Sump Pump

  • The purpose of the inverter is threefold. First, it keeps the battery charged at all times so that any kind of exigency can be handled. Second, is being able to sense when the power is missing and quickly revert to the inverter setting. Lastly, it converts the power stored in your batteries from DC to AC and proceeds further.

  • Though inverter and UPS work in the same way using the latter is not sensible in such a condition. The battery in a UPS cannot work for so long and that is the biggest disadvantage it can have. UPS systems have small battery chargers and thus its processes are inhibited.

  • Apart from that, an inverter offers more flexibility in comparison to a UPS system. Being inexpensive and easy to assemble, the inverter can easily be expanded in the future if required.

How To Install Battery Backup To Existing Sump Pump

how to install battery backup to existing sump pump

It is fairly easy to set up your Battery Back -up Sump Pump and you can do so in three easy steps.

  • Mounting the unit- You must mount the battery back-up at a wall-mount and a considerable distance from the AC outlet. The battery needs to be placed less than 4 feet from the pump. Make sure that the battery is encased in a strong battery box that would stand the impact of wear and tear.

  • Make the connections- After mounting, check if the main point is in off position. Connect that battery cables as mentioned in the manual. You must plug the pump into the AC outlet and then turn its power on.

  • Test installation- Lastly, check whether the installation has been done correctly. Cycle the pump to see if it is operating as per the specifications. You should remove the power cord to see if the back -up has been connected correctly. Cycle the pump again to see if the unit has been connected and is using the backup power.


Q1. What Happens When Your Sump Pump Loses Power?

When there is no power, your sump pump would not function at all. That means there would be no pumping action happening and all the snow and rain would slowly start piling up. This means that once thawing happens, there could be flooding in your home and areas around it. If you are around to fix the situation then things are fine. However, if you are not at home you can expect chaos and a worse situation when you come back.

Q2. Can you count on your sump pump?

A sump pump’s basic purpose is to keep pumping the snow and rain away. In most situations, it keeps functioning as per the specifications. However, when power is not there, any sump pump can breakdown and stop doing the needful. To handle this situation, a battery back- up is generally advised.

Q3. What causes primary pumps to fail?

A sump pump can face many issues during operations. A water-powered sump pump may be subjected to clogging and that can be a dangerous possibility. Its discharge lines could also get jammed or frozen causing the pump to stop working properly. Apart from that, if your basement has already got full of water the sump pump would not be able to handle the pressure and cause things to fail.

Q4. Back-Up Options For Existing Sump Pump?

You can get a battery back- up for an existing sump pump. These are easily available at hardware stores. Apart from that, an inverter can also be a suitable option as it handles even the toughest of breakdowns with ease. Moreover, you can assemble it quickly and even increase its loading capacity if need be. UPS is mostly not suitable for such a condition as it is unable to handle the load requirement.


When it is snowing your sump pump keeps the situation under control. However, when a power outage happens the sump pump would not function and get a battery back- up then is the most obvious and sensible thing to do.

Look around for the most suitable options that are available ensuring that it can handle the pressure of your house. Mostly a high capacity inverter back-up can take care of such issues, you just need to find which product is the best suited for you.