Sump Pump Battery Backup – Is It Possible & How?

A sump pump is a homeowner’s first line of defence against flooding, effectively removing excess water from basements and crawl spaces, particularly if they’re near or below the water line. 

However, a sump pump’s reliability hinges on access to a constant power supply. Interruption during a blackout — particularly during a storm — can leave you without power to your sump pump when you need it most. The flooding that may occur without an operational sump pump can be catastrophic. 

If your home has a basement or other areas prone to flooding, you need to invest in a reliable battery backup system for your sump pump. 

Learn about what to look for here. 

What Causes Sump Pumps to Fail, and How Can You Detect the Signs?

If portions of your home are built near or below the water table, a sump pump is probably essential to keeping your basement or crawl space dry during heavy rains, snowmelt, or plumbing emergencies. 

Any sump pump failure — especially during extreme weather events — can devastate your home. 

What exactly causes sump pumps to fail? 

Here are some common culprits.

Power Outage

A power outage is one of the most common causes of sump pump failure. Sump pumps rely on electricity to function. A blackout during a storm or heavy rainfall can render them useless at the worst possible time.

A backup battery system or generator is a necessity for a sump pump to protect your property from the ravages of flood damage reliably, 

Insufficient Operating Capacity

Smaller sump pumps are often ill-equipped to handle heavy water flow from events like a rapid snowmelt or severe rainstorm. 

If your sump pump is too small to handle the amount of water it needs to pump out, it can quickly burn out or become overwhelmed.

Inexpensive Pump

Buying a cheap sump pump may seem like a win. But when the motor burns out or the pump gets overwhelmed, any money you’ve saved will almost surely be exceeded by the costs of repairing water damage to your home.

The best way to protect your property is to purchase a high-quality sump pump with enough operating capacity to keep the vulnerable areas of your home dry.

Float Switches

Most sump pumps rely on a float switch to indicate when its internal tank is full. Float switches rise as water accumulates inside the tank, switching the pump on automatically when the liquid reaches a predetermined level.

If the float switch becomes stuck or damaged, it will prevent your pump from turning on and doing its job. 

If your pump uses a wide-angle tethered switch and fails to operate, a stuck float is likely the cause. Free-floating tethered switches can easily get trapped, stopping the pump from turning on automatically.

Signs of Sump Pump Failure

With some due diligence, you can often determine if a sump pump is deteriorating before it fails. 

Here are some of the tell-tale signs that your sump pump is in distress:

  • Excessive or unusual noise
  • No water in the sump pit
  • Irregular water cycling
  • Old age
  • Clogged discharge lines
  • Long run time
  • Runs continuously
  • Failure to turn on
  • Visible rust
  • Flooding

How Do Sump Pump Battery Backups Work?

Sump pumps rely on electricity. 

Aging infrastructure and extreme weather events are two common causes of power outages. Both can leave your sump pump powerless just when you need it most.

There are several steps you can take to ensure your basement stays dry — even in a blackout. 

  1. Purchase a Battery-Operated Backup Pump: Adding a battery-operated sump pump to your flood prevention arsenal gives you a viable option to keep your home safe when on-grid electricity is unavailable. In addition to (not in place of) your primary pump, a battery-powered sump pump can give you a safety net when electricity is unavailable. Because your sump pump likely operates automatically and frequently, a battery-powered pump is not recommended as an everyday solution. It should only be used as a backup option. 
  2. Invest In a Portable Power Station: A reliable battery backup system for your existing sump pump is likely more affordable than purchasing a backup pump. 
Sump Pump Horsepower RatingAverage Wattage
1/3 hp800 (Running)1300-2900 (Starting)
1/2 hp1050 (Running)2150-4100 (Starting)

Residential sump pumps typically come in one of two horsepower ratings: ⅓ hp and ½ hp. When shopping for a portable power station or generator to back up your sump pump, it’s essential to understand the difference between starting and running watts.

Most motor-driven appliances — like sump pumps — require more electricity to start than to run, sometimes double or triple the power. The distinction between starting and running wattage is unimportant when you’re connected to the electrical grid. But if you’re attempting to operate an appliance using a battery backup or generator, the unit must produce sufficient starting watts to turn the device on in the first place. 

As you can see in the table above, the starting watts (also known as surge power) that sump pumps require can be substantial. EcoFlow’s DELTA 2 Max offers sufficient starting and running AC output (2400W running, 5000W surge) to back up even the most demanding ½ hp sump. 

Battery Backup Sump Pump Systems: The Pros and Cons

If you rarely experience power outages, it may not be worth the cost and installation of a backup battery pump. 

However, if you’re concerned with the possibility of an extended outage and don’t want to risk potential damage to your home, investing in a battery backup sump pump system can be well worth the price.


  • Reliability, even when there’s no power
  • Works without a water supply
  • Easy to install by connecting to a discharge pipe or running a new pipe
  • Peace of mind and security that your basement won’t flood


  • Small batteries may not last long enough; substantial battery capacity may be necessary
  • Maintenance – check water levels every few months, check battery terminals every six months, and replace lead acid batteries every few years. Monitor lithium-ion batteries for decline in performance.

How to Select and Size Your Sump Pump Battery Backup?

If you’re in the market for a sump pump backup system (backup pump with battery included), here’s what to keep in mind:

  • Size: You need a sump pump backup large enough to handle water volume but small enough not to cost you a fortune. Gallons per minute (GPM) or gallons per hour (GPH) are the most commonly used metrics for assessing performance. The average capacity for sump pumps varies from 35 GPM to 60 GPM. If your existing pump does a good job when there’s electricity, match its capacity or go a bit higher if you’re concerned about extreme weather. You can also measure the head’s vertical lift distance and the sump pit’s diameter and match them with your backup pump system.
  • Dollars to Value: As with most things, you get what you pay for. A long-lasting, high-quality backup pump is usually a better investment over time. Look for a vertical float switch, a stainless steel, aluminum, or cast iron body, and a UL and CSA rated motor.
  • Energy Efficiency: Look for a low amperage model to avoid burning out the float switch.
  • Solid Passing: Find a top suction pump that can handle a bit of sand or gravel to prevent burnout.

Consider the following if you’d rather add a portable power station, solar generator, or other backup battery system.

  • AC Output and Battery Capacity: Assessing your sump pump’s power requirements is essential. Most sump pumps require 800-1050W to run and anywhere from 2150-4100W of surge power. The best EcoFlow portable power station options are the DELTA 2 Max (2400W, 5000W surge) or the DELTA Pro (3600W, 7200W surge). A RIVER 2 Pro (800W, 1600W surge) may be sufficient if your pump is on the smaller side. Keep in mind that a higher wattage PPS can back up additional appliances in your home. 
  • Recharge Rate: Look for a battery system that can recharge quickly so it’s always ready to use. EcoFlow’s portable power stations offer long-lasting LiFePO4 battery chemistry and the fastest recharge times in the industry.
  • Reliability: The LFP (LiFePO4) batteries in EcoFlow’s current range of PPS last for up to 10 years of daily use before diminishing in performance. If you only use the PPS for backup in power outages, your battery could last for decades.
  • User-friendly Design: A battery backup with a user-friendly interface makes it easy to monitor system readiness — even when you’re not in the basement. Thanks to the EcoFlow smartphone app, its portable power stations and solar generators offer remote control and monitoring from anywhere with an internet connection.

Final Thoughts

The old saying “better safe than sorry” certainly applies when it comes to sump pump battery backups. 

With extreme weather events and blackouts on the rise nationwide, investing in a battery backup system to protect your home is money well spent. 

Check out EcoFlow’s portable power stations today and ensure your home stays dry even when the lights go out.

EcoFlow is a portable power and renewable energy solutions company. Since its founding in 2017, EcoFlow has provided peace-of-mind power to customers in over 85 markets through its DELTA and RIVER product lines of portable power stations and eco-friendly accessories.


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