Informational Guide

Water Powered Backup Sump Pump Vs Battery

by Andrew

Sump pumps are most valuable when there are extreme weather conditions, but unfortunately, this is when an outage can impact the sump pump power supply. It's important to have a backup sump pump for these situations.  

Backup sump pumps use an alternative power supply separate from your mains electricity and will kick in as soon as your sump pump stops working. There are two main types: water-powered and battery-powered.  

In this guide, we'll give the breakdown of water powered backup sump pumps vs. battery powered backup sump pumps so you can better understand the pros and cons and which is best for you.   

Water powered backup sump pumps are a modern option that hasn't been around for as long as battery powered models. At first glance, they can seem complicated, but they're fairly straightforward and operate using something called the Venturi effect 

The pump is attached to your sump basin (where the excess water gathers in your home) and the main water supply. Water from the main supply is drawn through the pipes at high-speed generating suction. This suction then draws the water up from the sump basin and into the pump so it can be directed to your drain line and away from your home.  

Water powered sump pumps were first developed as the ultimate backup. They have very little reliance on outside forces or any power supply, so they can continue operating in most conditions. They can also run for an indefinite period of time because there's no power consumption.  

This means they can continue to drain water even if there's a power outage for several days, and it can literally mean the difference between a flooded home or a dry one. There’s also very little maintenance required with no battery power to monitor and nothing to replace.  

The downside of water-powered backup sump pumps is that they won’t work in every home. You need a certain amount of water pressure and flow rate to generate enough suction, and your area needs specific types of plumbing. They also don’t pump anywhere near as quickly as battery powered sump pumps, so it takes longer to remove water. The installation is also a bit more complicated, and you should expect to pay more to get the work done.  

Water powered backup sump pumps offer an excellent, power-free way to remove water from your home. They’re well suited to homes at risk of longer-term power outages, or regular flooding, because you know they’ll keep running.  

They’re often used by holiday homeowners who won’t be there year-round because it gives them confidence that the backup sump pump will run year-round regardless of the conditions. Just be careful because water powered models won't pump water as quickly as battery powered backup sump pumps. 

covering sump pump

Pros & Cons of Water Powered Models 

What We Like 
  • Able To Run Continuously For Days 
  • No Battery Or Power Source Needed 
  • No Running Costs 
  • Low Maintenance 
What We Don’t Like 
  • Pumps Less Water Per Hour Than Battery Sump Pumps 
  • Reliant On Municipal Water Supply 

Battery-Powered Backup Sump Pumps Explained 

Battery powered backup sump pumps have been used for decades as a safety precaution to prevent flooding in the home. The concept is simple, if the primary power source (mains electricity) is disrupted due to an outage or surge, then the battery pack will kick in and keep the sump pump running. This allows the pump to continue to empty the sump basin and get excess floodwater out of your home.  

Battery powered backup sump pumps are simple and convenient, and most modern sump pumps come with a battery pack built-in. They offer more power than water powered equivalents and will, on average, pump 1750 gallons of water per hour (GPH) compared to only 900 GPH for a water powered backup sump pump. This is a huge discrepancy, and if there's a significant flood, you’ll definitely want a battery powered model. Battery powered backup sump pumps are easy to install and can be used in almost any home.  

The downside with battery powered backup is all related to the battery life. There is a limited run time for these battery packs, and you will only get 8-12 hours with most models. The batteries themselves will need to be replaced every 3-5 years too, so there is more maintenance involved.  

Battery powered sump pump backups are well suited to most homes and have no reliance on the municipal water supply. They're simple and affordable, so they will do the job well in most cases. They are less well suited to homes that may experience longer periods of outages and regular flooding, and in these cases, water powered backup is the better choice.  

sump pump hole

Pros & Cons of Battery Powered Models 

What We Like 
  • Powerful Water Pumping 
  • Can Be Used In Any Home 
  • Low Cost  
  • Built-in To Some Sump Pumps 
What We Don’t Like 
  • Limited Run Time 
  • More Maintenance Needed 

Water Powered Vs. Battery: Which Backup Sump Pump Is Best? 

Pump Run Time  

Battery backup sump pumps can run for over 48 hours, but if they are in heavy use and cycling regularly, then you can only expect 8-12 hours of power. This usually provides adequate cover to get your power back online and the primary sump pump running, but you can get some more expensive battery packs that last longer.  

Water powered backup sump pumps will run continuously because they aren’t reliant on any external power source. This means they can continue pumping water out for days even if your main power source hasn’t come back up.  

If you know you’re potentially going to have long periods without power, then a water powered backup sump pump is the better choice to protect your home.  

Pumping Rates and Capacity  

A water powered backup sump pump is less powerful than a battery powered model. A typical ¼ horsepower (HP) battery backup will pump 1000 GPH, and a 1/3 HP battery backup will pump around 1800 GPH. In comparison, a water powered backup sump pump will only pump 800-1200 GPH, so a battery powered model will remove significantly more water per hour. 

If you live in an area that suffers from extreme weather conditions, then a water powered backup sump pump may just not cut it.  

Longevity and Effectiveness  

There’s no denying that a battery powered backup sump pump will be more effective at removing water, but it also has a limited lifespan. The battery power will only last 8-12 hours, and the batteries themselves can only last 3-5 years before they need to be replaced.  

In contrast, a water powered backup sump pump will run continuously, and a good model can last over 20 years. This means that over time they will protect your home more effectively and give you better value.  

If you know you suffer from regular outages and flooding, then a water powered model is the better choice.  

Installation & Maintenance 

Battery powered backup sump pumps are simple and cheap to install. Many major brands already have a battery pack included, and if not, you can do it yourself pretty easily. You will have to check the battery power regularly and replace the batteries from time to time, though, so there is some maintenance involved.  

Water powered backup sump pumps are more complicated to install. You need to have a good flow of water going through your home for them to work, and you will probably need a professional to help you. The downside is that the installation can be expensive, but the upside is that there’s very little maintenance involved to keep them running.  

If you want to save money upfront and are prepared for the maintenance involved, you should go for a battery powered backup sump pump. If you're prepared to spend a little more and don't want the maintenance, then you should go for a water powered backup sump pump. Remember that if you have a sump pump in a holiday home that you only visit at a particular time of year, you may be better with a water powered backup sump pump, which will run without maintenance.  

Unit & Installation Cost 

A battery powered backup sump pump will cost between $200 and $1000 depending on the exact specifications. The installation costs are minimal, but replacement batteries are $200-$300, and you'll need to buy these every few years.  

The price of water powered backup sump pumps varies massively depending on the make and model. Typically, you can expect to spend $500-$1500 on the model itself and another $300-$1000 on installation costs. Of course, this is all influenced by your exact setup and location, but if you have a tight budget, then a battery powered backup is the best choice.  


People also Ask (FAQs)

Can you add a battery backup to an existing sump pump? 

Yes, you can add a battery backup to almost any sump pump. Some sump pumps come with a battery backup already connected, but if not, you should check the user manual to make sure it's compatible.  

Who can install a battery backup sump pump? 

It’s possible to install a battery backup sump pump yourself, but any plumber or contractor involved in sump pump installation can do it for you.  

Are water powered backup sump pumps reliable? 

Yes, because of the straightforward design, they don't have many individual components which can break, so they are a reliable way of removing water from your home.  

Do water powered backup sump pumps need maintenance? 

Water powered backup sump pumps need very little maintenance. It's recommended that you clean and inspect your whole sump pump system every 1-2 months, and it's worth checking your water-powered backup at the same time.  


A backup sump pump is essential for every homeowner who experiences flooding or power outages. Water powered and battery powered backup sump pumps both have their advantages and disadvantages. For homes that experience longer power outages, it's worth paying more for a water powered model, but for most homeowners, a cheaper battery powered model will do the job. Hopefully, this guide has given you some useful information and helped you determine which is best for your home.