Best Deep Cycle Battery for Sump Pump

6 Best Deep Cycle Battery for Sump Pump in 2023

Choosing the best backup battery for your sump pump can be backbreaking as many battery options are available in the market. But, you can’t buy any of those RV / regular use batteries as a backup battery system for the sump pump.

Sump pumps require stronger batteries that can take the heavy load of two pumps simultaneously. That’s why deep cycle batteries are there. Here we’ll discuss the best deep cycle battery for sump pump.

So, without further ado, let’s begin.

Quick Summary

Here’s a quick summary of the best choice for backup batteries for a sump pump.

“The best spill-proof AGM Deep Cycle, no-maintenance battery.”

“Dedicated Sealed Sump Pump Battery”

“Most efficient and the least self-discharge rated backup battery.”

Longer shelf life, a heavy-duty backup battery that comes at a very reasonable price”

  • Best Deep Cycle Gel Cell Battery: MK Deep

“Best lightweight valve-regulated deep cycle battery.”

“Best backup system for the sump pump in a suitable budget”

6 Best Deep Cycle Battery for Sump Pump

While choosing these models, we considered durability, built quality, efficiency, and shelflife of the batteries. After researching each product thoroughly, we presented the thoughts here.

1. Universal Power Battery

Universal Power Group 12V 100Ah Solar Wind AGM SLA DEEP Cycle VRLA Battery 12V 24V 48V
  • UB121000 SLA is a 12V 100AH ​​Group 30H Sealed Lead Acid (SLA) Maintenance Free Rechargeable Battery, UL Listed
  • The spill-proof SLA/AGM battery features high discharge rate, wide operating temperatures, long life and deep discharge recovery.
  • Rechargeable battery that can be mounted in any position, resists shock and vibration. Long lasting high performance in high and low temperatures.
  • UPG #45978 UB121000

 If you’re looking for the best value AGM deep cycle battery, the Universal Power Group battery is the right choice for you. It is a 12Volt 100Ah AGM battery. It is a sealed lead-acid battery.

What makes this battery the perfect sump pump battery is that it’s spill-proof. So, you have nothing to spend extra on maintenance. That means it’s not required to refill the battery with distilled water or acid. So, the battery is easy to operate.

Absorbed Glass Mat batteries are relatively higher in price than other lead-acid batteries. But, you get a Universal Power Group battery (AGM) at half of the price of other AGM batteries. That saves you a lot of money.

The casing might not look attractive, but it’s pretty durable. Besides, the battery is rechargeable and resists shock and vibration.


  • SLA/AGM maintenance-free
  • Sealed spill-proof battery
  • High-quality, durable casing
  • Lightweight premium quality


  • Risk of fire, explosion, and burns
  • Not bearable above 65 ℃

2. PumpSpy- AGM Deep Cycle Battery

PumpSpy Deep Cycle Battery - Maintenance-free AGM Battery w/ 12V 75Ah Mounting Flexibility, 12V AGM 75Ah Ideal for Start-stop Applications, Insusceptible to Vibration, Handles High Electrical Loads
  • MAINTENANCE FREE - No more frequent maintenance through regular addition of water or acid just to have a proper operation. Our AGM deep cycle battery 12v pack will rescue you from the danger of acid leakage and frequent water refill.
  • SEALED LEAD ACID BATTERY - You can now eliminate spilled acid from a tipped battery and hydrogen gas venting because our AGM 12v deep cycle battery is completely sealed, averting any form of leakage.
  • BETTER CYCLING PERFORMANCE - Our Absorbent Glass Mat (AGM) Technology enables low internal resistance and high discharge currents. This valve regulated rechargeable battery 12v allows dependable operation in any position.
  • FAST CHARGING TIME - Quickly recharge your AGM deep cycle battery 12v up to 5x faster than a standard flooded battery. The improved electrolyte formula ensures stable battery capacity with increased cycle life and vibration resistance.
  • CONVENIENT AND FUNCTIONAL - Efficient to use, our AGM battery 12v has an internal compression that limits the shedding of plate material caused by cycling, which also allows a significantly longer life. It is designed for demanding conditions and can handle high electrical loads.

Pump Spy 12Volts 75Ah battery is an SAE Terminal AGM battery which is specially designed for Sump Pumps. As the battery is specified for use, it brings more reliability.

You’ll get this battery if you buy a Pump Spy backup battery system whole kit.

Being an AGM battery Pump Spy deep cycle battery ensures no leakage and no maintenance requirement, which saves you a lot of hassle.

The sealed design increases the movability of the battery without any spilling issues. Next, the overall battery construction is durable and capable of bearing heavy load usage.


  • No water refilling issue
  • No acid leaked
  • Constructed for sump pump use
  • SAE Terminals
  • Lightweight of 49 pounds only


  • Can be explosive in too much heat

3. Renogy Deep Cycle AGM Battery

Renogy Deep Cycle AGM 12 Volt 100Ah Battery w/ Box, 3% Self-Discharge Rate, 1100A Max Discharge Current, Safe Charge Appliances for RV, Camping, Cabin, Marine and Off-Grid System, Maintenance-Free
  • 【Warranty】2-year material and workmanship warranty guarantee.
  • 【Maintenance Free & Safe to Use】No acid leakage, no water refilling, and no harmful hydrogen gas. Manufactured with thick absorbent glass mat (AGM) separators and advanced valve-regulated technology, Renogy Deep Cycle AGM Batteries save you from acid leakage and frequent maintenance.
  • 【Better Performance at Extreme Temp】The improved electrolyte formula ensures stable battery capacity and outstanding discharge performance from 5℉ (-15℃) to 122℉ (50℃).
  • 【Longer Shelf Life】No need to recharge the battery frequently when not in use. Made of high-purity materials, Renogy Deep Cycle AGM Batteries reduce the monthly self-discharge rate below 3% at 77℉ (25℃), which is 5 times lower than their flooded counterparts.
  • 【Outstanding Discharge Performance】Proprietary quinary alloy plates and exclusively treated plate grids enable low internal resistance and high discharge currents of up to 10 times the battery-rated capacity. This means that Renogy AGM batteries can power home appliances with high current ratings.

Advanced VRLA (Valve Regulated Lead Acid) batteries are the newest craze for sump pump systems. If you’re searching for the same, Renogy Deep Cycle AGM Battery is the one for you.

It’s an AGM deep cycle battery that comes with VRLA technology and in a sealed format. So, you don’t need to refill or maintain the battery at all.

It’s a 12 Volts, 100Ah battery. That means the battery can run for hours during a power cut and run your sump pump well. For high current discharge and low resistance, the battery has quinary alloy plates within.

This battery decreases the monthly self-discharge rate by 3% at 77℉. It’s five times lower than the brand’s flooded lead-acid batteries. The battery contains an improved electrolyte formula that efficiently maintains the charge cycles properly.


  • Can run the pump for a long time
  • Suitable to run heavy home appliances with the battery
  • High capacity and fast charging cycles
  • Improved electrolyte formula


  • Not suitable to charge in an airtight container


THE BASEMENT WATCHDOG Model BW-27AGM Maintenance Free (AGM) Sump Pump Battery
  • Maintenance free - no need to add battery fluid or distilled water
  • 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, CITS-50)
  • 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, CITE-33)
  • Runs various Basement Watchdog sump pump systems intermittently for days

The Basement Watchdog Backup Battery is another backup battery specially designed for sump pumps. If you’re installing a total new sump pump system, this model can assist you the best.

When there’s a power cut, the backup battery will activate and start to flow energy to the backup pump, and then the main pump to run for hours and even days in some cases.

This battery doesn’t require any maintenance at all. Install it and forget the rest.

However, if you’re setting this newer model battery with an older Basement Watchdog Sump Pump, it may not be able to run the unit.

In that case, get a new control box, and you’re good to go. But, it becomes a bit costlier for some people.


  • Longer shelf life
  • Heavy-duty usable
  • Can run for several hours to days
  • No maintenance needed
  • Sealed battery system


  • Not compatible with older Basement Watchdog Sump Pump models

5. MK Deep Cycle Gel

MK Deep Cycle Gel Cell 12 Volt Battery for Backup Sump Pumps
  • Durable Polypropylene case
  • Self-sealing vent system prevents loss of internal fluids
  • Self-sealing vent system prevents loss of internal fluids
  • Self-sealing vent system prevents loss of internal fluids
  • Self-sealing vent system prevents loss of internal fluids

MK Batteries has the best technology built-in batteries. It is a subsidiary of the world’s largest technologically advanced single-site battery manufacturer, East Penn Manufacturing Co., Inc. That being said, you already understand what qualities MK Batteries have.

The MK Deep Cycle model is specially designed and engineered for sump pumps. Being a VRLA deep cycle battery, this model from MK has the ability to recharge faster and work more effectively.

It can run as a heavy-duty battery. It’s better than most of the other marine deep cycle batteries on the market.

This gel cell battery holds the charge longer, and with gel electrolyte being the prime component, there’s no chance of leakage to spill acid from the battery.


  • Valve regulated deep cycle battery.
  • Polypropylene-based air-powered sump pump  backup battery
  • Easy to carry and install


  • Not suitable to use in a too-warm area

6. SEC America Backup System

822PS - Sump Pump Backup System
  • HOW IT WORKS: Pump Sentry will reliably power your sump pump during a power outage; it automatically switches to battery when AC power goes out & will automatically recharge when power is restored
  • FEATURES: UL & CSA accredited, this 1200 Watt battery backup is compact; it’s designed to operate most sump pumps up to 9 amps & comes with indicators for power output, battery charge, & battery replace. Not for use with pedestal pumps.
  • COMPACT & DURABLE: This sump pump battery backup is housed in rugged aluminum & comes in a compact size; supports full pump capacity & can be easily installed; it offers a silent & clean operation
  • WHAT YOU NEED: For functionality of the battery backup, connect a 12Volt deep cycle marine battery (purchased separately) with a capacity rating between 90 & 200 ampere hours; battery cables included
  • BRAND PROMISE: We take pride in our rugged, built-to-last products & offer a 2-year factory warranty on our sump pump battery backup system; made & serviced in the USA

Pump Sentry 822PS System is different from the other listed products above. It’s an actual backup system for the sump pump but not the battery.

Usually, the backup sump pump for your main pump is a cheaper plastic material. And in order to install it, you’ve to take the whole pump unit out. This hassle was just to make sure the DC flew to the main pump during a power outage.

Pump Sentry 8222PS does the job without any additional pump. That means, if you install the unit with your primary pump and battery, the system will start to work when there’s no AC flow.

It’ll take the recharged power from the battery and flow it as DC to run the pump instantly. When the power is back, it’ll turn off automatically and get back to charging mode for future use. Again AC will flow to your pump as usual.

This system needs to be installed above the minimum water level of the crawl space. If you’ve set up the sump pump system in your basement, you can install this battery backup system on the basement wall.


  • Manages the current flow without any interruption
  • No manual setting required
  • Indicator lights tell about lousy battery, fully charged, and trickle charged mode.
  • Build with durable material


  • Designed to be hooked up with a marine battery, not the regular ones

How to Pick the Perfect Backup battery for Sump Pump

Sump pump battery selection isn’t similar to a car battery or any RV battery selection. You need to get a battery that can deal with the load of the sump pump when there’s a flood during a power outage.

Hence, here’s a definite guide on picking the perfect battery for a sump pump.

Types Of Battery

Before getting into which type of battery is going to suit the sump pump, you need to understand the types of batteries. You’ll find lead-acid backup batteries in the market as these are the most common ones.

Lead-acid batteries have improved over time and are marketed in three major kinds at present. They are –

Wet Cell Batteries

Among all batteries, a wet cell is the cheapest kind. They’re basically the ones which require periodic inspection and regular maintenance. They’re called “Wet Cells” as the main components of the battery are submerged in the lead acid. That’s why they’re also known as the “Flooded Lead-Acid Batteries”.

There’re two kinds in this case. Some are sealed, spill-proof wet cell batteries, and some are unsealed maintenance-required wet cell batteries. The unsealed ones need to put distilled water in to maintain the batteries for a more extended period and prevent the cells from drying out.

AGM (Absorbed Glass Mat) Batteries

AGM batteries are more expensive and the most efficient type, indeed. They’re safer as there’s no floating acid inside the battery, and it’s sealed.

Inside the battery, the glass fiber material is placed that compresses the lead-acid cells to absorb electrolytes. Unlike other batteries, the cells are wet enough to produce power but not sunk in.

These batteries don’t require any maintenance, and you don’t have to worry about keeping the battery fed to work constantly with water.

Gel Batteries

Gel batteries are sealed type maintenance-free batteries. The electrolyte fill component in this battery is a silica gel-based electrolyte.

These batteries are perfect for preventing vibration and noise as they don’t evaporate or leak. The most common use of these batteries is in racing or in situations where vibration and shakes are a considerable matter of fact.

Best Type of Backup Battery for Sump Pump

The best type of backup battery system for the sump pump is the “deep-cycle” battery. A deep cycle isn’t a type of battery; instead, it’s the standard lead-acid battery with the deep cycle feature.

“Deep Cycle” means the cycling capability of the battery. Each cycle consists of discharge and recharge. These batteries can’t deliver a higher current like a wet cell battery, but they can provide a faster charge that can operate for a more extended period.

Durability & Strength

The casing quality and durability of the battery are considerable facts as well as the battery type.

You’re going to use the backup battery to operate your sump pump when there’s a flood in your basement, or heavy rainwater is floating inside your house. So, the battery should be durable enough to withstand the stormy conditions and work through.

A light casing may get damaged in tough situations and ultimately, it won’t benefit you at all.

Power Output And Operating Duration

Backup battery sump pump systems require high/standard voltage batteries. In the backup system, generally, the battery needs to take the load of two pumps (primary and backup).

That’s why the power output needs to be high enough to run smoothly. Usually, a 12 Volts, 5/10/15 Amps deep cycle battery works great for this kind of situation.


When the features of your desired backup battery match your requirements, it’s time to think about the cost.

If you go for a wet cell battery, that’ll cost you less initially, but it’d make you spend money afterwards for maintenance. Besides, the time you’ll spend maintaining the battery is also a fact to consider.

If you go for a deep cycle lead-acid battery, that may cost you more, but it’s worth it. You don’t need to worry about anything else after installing the backup battery with your sump pump.


What type of battery is best for a sump pump?

Deep cycle lead acid batteries are best for sump pumps. Often these kinds of batteries are called marine batteries. They’re mostly maintenance-free and rechargeable.

How long will a 12v battery run a sump pump?

If your battery is totally new and fully charged, it can continuously run for 5-7 hours. You can go up to 2/3 days if you’re not continuously using the battery. However, the battery’s amp hours also matter in determining the running time capability of a battery.

How long will a deep-cycle battery run a sump pump?

In most cases, sump pump backup batteries are powered with 12 Voltage range. These batteries run good enough for 5/7 hours a day when used simultaneously.

How long do sump pump batteries last?

Usually, sump pump batteries last for 4-5 years. There are some sump pump dedicated batteries that can last for 8-10 years. However, they’re more well-constructed and expensive batteries.

Can you use any battery with the basement watchdog?

You should use the Basement Watchdog battery with its sump pump unit. The pump and the backup battery should be of exact model combination. Using a newer Basement Watchdog battery won’t work in an older Basement Watchdog Sump Pump Unit.

Will a power inverter run a sump pump?

You can use a power inverter to run a sump pump. The main job of the converter is to convert the current supply during a power cut and it goes ok with the sump pump. Yet it is suggested to use a sump pump backup unit.

How often replace the backup sump pump battery?

The typical and minimum warranty of a backup sump pump battery is 5 years from the majority of the manufacturers. You should change the battery every 5 years of usage. Still if you inspect the battery and find out it can go further, you can keep using it.

Can I use an AGM battery for the sump pump?

AGM batteries are the best options to use for a sump pump. It would especially be best if you can get a Gel Cell AGM battery for your sump pump.


If you’re thinking about getting a backup battery for your sump pump, consider looking at the batteries listed above. We suggest the “PumpSpy AGM Deep Cycle Battery” as the best deep cycle battery for sump pump.

The reason behind choosing this one is, the battery is specifically manufactured for the purpose. Besides, the normal-looking durable casing with lightweight features makes it the best suit to bear a load of a backup sump pump system effortlessly.

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