Backup Power for Sump Pumps: The Ultimate Guide to Ensure a Dry Basement
Discover the peace of mind of having reliable backup power for sump pumps to keep the basement dry.
If you’re a homeowner, you understand the importance of keeping your basement dry and protected against flooding.
In this article, we’ll delve into the world of backup power systems for sump pumps, providing you with all the information you need to make an informed decision.
Table of Contents
Sump Pump Power Requirements
Determining your sump pump’s power needs is the first step towards choosing the right backup power system.
We’ll guide you through the process of assessing your sump pump’s power requirements and explain why matching the backup power system to your pump is essential.
Factors to Consider When Choosing a Backup Power System
Selecting the right backup power system for your sump pump is crucial.
Everyone that can afford a permanently install a 10KW natural gas or propane backup generator should do so. This type of backup power for sump pumps is the most reliable and easiest to operate.
They automatically start and will run for as long as needed. The only limitation is the supply of natural gas.
An excellent alternative to a permanently installed generator is the Generac 7706 GP18000EFI 18,000-Watt Gas-Powered Electric-Start Portable Generator shown below;
The second best sump pump option is to have two primary sump pumps. The second pump acts as the backup sump pump and runs off of an inverter backup system. If the first sump pump fails to operate or can’t keep up with the amount of water flowing into the basement, the second pump starts up.
Having two primary sump pumps means that the secondary or backup sump pump is able to handle the same amount of water as the primary pump. Most backup sump pumps are smaller than the primary pump and may not be able to remove as much water as is needed.
Of course, the smaller backup sump pump will run for a longer time on an inverter with battery or stand-alone battery charge but the basement might get wet.
The solution is to have more than one backup battery to provide for a longer run time.
Shown below is a 1/3HP 12 volt backup sump pump that is the same size as most primary sump pumps used in homes. Which is important because you want the backup sump pump to pump as much water as the primary pump does. You should seriously consider the Zoeller 508-0006 Aquanot 508 ProPak53 Preassembled Sump Pump System with Battery Back-Up. The battery is not included. Meets California regulations.
Understanding Sump Pumps and Their Power Needs
Before we dive into solutions for backup power for sump pumps , let’s familiarize ourselves with sump pumps and their power requirements.
Sump pumps are essential devices that prevent basement flooding by removing excess water from the sump pit. Most backup sump pumps operate on electricity but there are water powered backup sump pumps available.
However, they all rely on a reliable power source to function effectively. We’ll explore how sump pumps work, discuss common power-related issues, and emphasize the need for backup power.
Does Your Home Lose Electrical Power Very Often Or For More Than A Few Hours?
Then the best backup power for sump pumps would be a backup generator. This is because a battery backup system would not provide adequate protection.
Also, a water powered backup sump pump will not provide electricity to the rest of the house.
I Don’t Want to Buy a Backup Sump Pump. What Should I Do?
The least expensive and easiest to install backup power for sump pumps in this situation is an inverter battery backup system
Shown below is the Sec America 1622PS – 1800 Watt battery backup system which is used with a 12 volt battery to power a primary sump pump and/or a backup sump pump that operates on 110-120 volts.
I Need Backup Power for Sump Pumps That Won’t Fail
The two most reliable systems to supply backup power for sump pumps are natural gas generators and water powered backup sump pumps.
A water powered backup sump pump is as reliable as the supply of city water. These sump pumps will operate as long as the city supplies water to the house.
Types of Backup Power Systems for Sump Pumps
When it comes to backup power for sump pumps, there are several options available. We’ll explore four main types of backup power systems:
1. Battery Backup Systems
Battery backup systems are the most commonly used backup power for sump pumps.
They are used to run the 12 volt backup sump pumps. Whereas the primary sump pump runs on 110-120 volts.
The runtime of a 75 amp-hour or 100 amp-hour battery powering a 1/3 HP or 1/2 HP basement sump pump can vary based on several factors.
Including the efficiency of the battery system and the power consumption of the sump pump.
Shown below is the very popular and highly rated WAYNE – 1/2 HP Primary Sump Pump and 1/2HP battery backup sump pump, with Integrated Vertical Float Switch
What Is the Range of Power Requirements for Basement Sump Pumps?
The power requirements for basement sump pumps can vary depending on the specific model and its intended use. However, the range of power requirements typically falls between 1/3 horsepower (HP) to 1 horsepower (HP) or approximately 250 watts to 750 watts.
Smaller sump pumps or those designed for residential use typically have power requirements in the range of 1/3 HP to 1/2 HP (250 watts to 375 watts).
These are suitable for standard residential basements and can handle moderate water inflow. See below.
| Product | HP / Performance | Key Features | Our Verdict |
|---|---|---|---|
Top Pick WAYNE CDU790 1/3 HP Submersible Sump Pump WAYNE • Cast iron & stainless steel | HP & Flow
| Highlights
| Verdict The WAYNE CDU790 is a workhorse 1/3 HP basement sump pump that balances power, durability, and quiet operation. Its cast iron and stainless steel construction stands up to long run times, while the integrated vertical float switch makes it an easy drop‑in upgrade for standard sump pits. |
Most Reliable Zoeller M53 Mighty‑Mate 1/3 HP Sump Pump Zoeller • Cast iron, Made in USA | HP & Flow
| Highlights
| Verdict The Zoeller M53 Mighty‑Mate is the gold standard for reliability in 1/3 HP sump pumps. Its cast iron construction and proven float design make it ideal for basements that see regular groundwater activity. |
Best Value Superior Pump 92572 1/2 HP Submersible Sump Pump Superior Pump • Thermoplastic | HP & Flow
| Highlights
| Verdict The Superior Pump 92572 delivers strong 1/2 HP performance at a very approachable price, making it a great value pick for typical residential sump pits. |
Heavy Duty Zoeller M98 Flow‑Mate 1/2 HP Sump Pump Zoeller • Cast iron, high‑flow | HP & Flow
| Highlights
| Verdict The Zoeller M98 is a premium 1/2 HP sump pump built for demanding basements that see heavy water flow or require long discharge runs. |
For larger basements or areas with higher water inflow, sump pumps with power requirements of 3/4 HP to 1 HP (560 watts to 750 watts) may be required.
| Product | HP / Performance | Key Features | Our Verdict |
|---|---|---|---|
Top Pick WAYNE CDU980E 3/4 HP Submersible Sump Pump WAYNE • Cast Iron & Stainless Steel | HP & Flow
| Highlights
| Verdict The WAYNE CDU980E is the best all‑around 3/4 HP sump pump for basements that see frequent or heavy groundwater. Its cast‑iron build, strong GPH output, and reliable vertical float make it a dependable upgrade for homeowners who need more power than a 1/3 or 1/2 HP pump can deliver. View on Amazon |
Heavy Duty WAYNE CDU1000 1 HP Submersible Sump Pump WAYNE • Cast Iron & Stainless Steel | HP & Flow
| Highlights
| Verdict The WAYNE CDU1000 is a powerhouse 1 HP sump pump built for basements that experience heavy water intrusion, long discharge lines, or high‑volume pits. If you want maximum pumping capacity with proven reliability, this is the top choice in the 1 HP class. View on Amazon |
These pumps provide greater pumping capacity and are more suitable for heavy-duty applications.
For larger homes or for greater water removal, consider THE BASEMENT WATCHDOG Big Combo CONNECT Model CITS-50 1/2 HP Primary and Battery Backup Sump Pump System. It is Smart WiFi Capable and has a 24 Hour a Day Monitoring Controller.
It’s important to refer to the manufacturer’s specifications or the label on the sump pump itself to determine the exact power requirements for a specific model.
This information will help ensure that the backup power system you choose, such as a battery backup, generator, or inverter, can meet the power demands of the sump pump effectively.
Battery Capacity and Runtime
For battery backup systems, battery capacity and runtime play a crucial role in providing uninterrupted power.
We’ll explain their significance and offer practical advice on selecting the appropriate battery capacity and runtime for your needs.
It’s important to note that these estimations are approximate and can vary depending on factors such as the age and condition of the battery, the efficiency of the battery system, the pump’s power consumption, and other variables.
Additionally, keep in mind that running a sump pump continuously for extended periods is not a good thing. That can strain the battery and reduce its overall lifespan. However, when the power is out and the backup pump is needed you don’t have a choice of how long the pump runs.
The runtime of a 75 amp-hour or 100 amp-hour battery powering a 1/3 HP or 1/2 HP basement sump pump can vary based on several factors, including the efficiency of the battery system and the power consumption of the sump pump.
A study by North Dakota State University found that new batteries will last from 4 to 11 hours of continuous running.
This run time will depend on the battery capacity, which varied between 40 and 120AH (Amp Hours).
Add THE BASEMENT WATCHDOG Model BWSP to the existing primary sump pump. See below.
The most popular backup sump pump batteries are the 75 amp-hour and 100 amp-hour batteries.
Here’s a general estimation of the runtime for 75 amp-hour and 100 amp-hour batteries with 1/3 HP and 1/2 HP sump pumps:
Note: These are continuous running times which is not what typically happens during a rain storm where the pump starts and stops during the day. Also, these are averages over the lifetime of the battery. Not what can be expected from a new battery.
75 amp-hour battery:
• 1/3 HP sump pump: The average runtime can range from approximately 1.5 to 4 hours.
• 1/2 HP sump pump: The average runtime can range from approximately 1 to 2.5 hours.
100 amp-hour battery:
• 1/3 HP sump pump: The average runtime can range from approximately 2 to 5 hours.
• 1/2 HP sump pump: The average runtime can range from approximately 1.5 to 3.5 hours.
2. Gas Generator Backup Systems
When considering generator backup systems, understanding power output is vital. We’ll discuss the importance of matching the generator’s power output to your sump pump’s requirements and provide guidance on selecting the right generator power output.
Generators are widely used as backup power sources for various applications, including sump pumps.
Buying a small gasoline powered backup generator to run just the sump pump isn’t the best option for a few reasons.
These generators would normally need to be manually started. They typically would run a utility sump pump that isn’t permanently installed in the sump pit.
Since they run on gasoline the gas tank will need to be refilled regularly.
Shown below is the Pulsar PG1200SG 1,200W Gasoline-Powered Portable Generator with a carrying handle. It just weighs 37.5 pounds which can be carried without much trouble.
So, the best backup generator to supply backup power for sump pumps would also power the rest of the house. These generators run on natural gas and are permanently installed outside the home. They start automatically. So, homeowners don’t have to be home when the power goes out.
What Size Electrical Backup Generator Is Needed to Run the Essential Power Needs of a New 3 Bedroom Home?
The size of the electrical backup generator needed to run the essential power needs of a new 3-bedroom home depends on several factors. Including the specific electrical load requirements of the home and the appliances you consider essential.
However, as a general guideline, a backup generator with a capacity of around 10,000 to 12,000 watts (10-12 kW) would typically be suitable for powering the essential circuits in a 3-bedroom home.
To determine the exact size of the generator needed, you should consider the following steps:
1. Identify essential circuits: Determine which circuits or appliances you consider essential during a power outage. This may include lighting, refrigeration, heating/cooling, water pump, sump pump, security systems, and basic outlets.
2. Calculate the electrical load: Add up the wattage requirements of the essential circuits and appliances.
You can find this information on the appliances’ labels or in their user manuals.
Make sure to account for both the running wattage and the starting wattage, as some appliances may require more power during startup.
3. Factor in additional capacity: It’s advisable to add a safety margin of around 25-30% to the total wattage calculated in step 2. This extra capacity allows for unexpected power spikes or the addition of extra loads in the future.
4. Consult an electrician or generator expert: It’s highly recommended to consult with a qualified electrician or generator expert.
Someone who can assess your specific electrical needs and recommend the appropriate generator size based on local regulations, load requirements, and installation considerations.
Remember, the size of the generator may vary depending on individual circumstances and the specific electrical load of the home. Therefore, it’s always best to consult with a professional to ensure the generator meets your specific needs and local requirements.
3. Inverter Backup Systems
Inverters offer an alternative backup power solution for sump pumps. We’ll explore the benefits and limitations of using inverters, discuss their compatibility with different sump pump models, and recommend reputable inverter brands and models for your consideration.
Inverter Capacity and Compatibility
If you opt for an inverter as your backup power solution, it’s essential to assess the inverter’s capacity and compatibility with your sump pump.
We’ll walk you through the process of determining the right inverter capacity and ensuring compatibility for seamless operation.
What Is the Inverter Capacity Needed to Operate a Basement Sump Pump Backup Battery?
An inverter backup system providing backup power for sump pumps still requires a backup battery. The difference is that the inverter can power any 110-120 volt sump pump. Whereas standard battery backup systems will only power 12-volt sump pumps.
The inverter capacity needed to operate a basement sump pump backup battery depends on the power consumption of the sump pump. To determine the required inverter capacity, follow these steps:
1. Identify the power consumption: Check the specifications of your sump pump or its user manual to find the power rating in watts. The power consumption can vary depending on the specific model and its size (1/3 HP, 1/2 HP, etc.).
2. Consider the starting surge: Sump pumps often require an additional surge of power to start up. This starting surge can be higher than the running power. Check the sump pump’s documentation or contact the manufacturer to determine the starting surge wattage.
3. Select an inverter capacity: Choose an inverter with a continuous power rating equal to or higher than the running wattage of the sump pump.
If the sump pump has a starting surge, the inverter should have a peak or surge power rating that accommodates that surge.
For example, if your sump pump has a running power consumption of 500 watts and a starting surge of 1000 watts, you would want an inverter with a continuous power rating of at least 500 watts and a surge power rating of at least 1000 watts to handle the initial startup.
It’s important to note that inverters come in various power ratings, such as 500 watts, 1000 watts, 2000 watts, etc. Choose an inverter that meets or exceeds the power requirements of your specific sump pump.
Additionally, consider the efficiency of the inverter. Higher efficiency inverters will convert more of the DC battery power to AC power for the sump pump, minimizing energy loss during the conversion process.
Always refer to the manufacturer’s recommendations and guidelines for the sump pump and the inverter to ensure compatibility and proper operation.
4. Water Powered Backup Systems
These operate on the amount of water pressured supplied by the city water system. The water powered backup sump pump operates by the city water causing a vacuum which sucks up the sump pit water.
The city supplied water line needs to be a 3/4-inch diameter pipe. Which provides enough water volume to operate the pump. Also, the 3/4-inch pipe provides greater water pressure than a smaller size pipe would allow.
Higher water pressure enables a higher flow of water from the water powered backup sump pump. Minimum water pressure would be 20 PSI and the maximum would be 90 PSI.
Shown below is the Basepump RB750 Water Powered Backup Sump Pump with Water Alarm. It is mounted on the ceiling of the basement. No electricity needed. Will run as long as needed.
Keep in mind that not all water powered backup sump pumps can operate at just 20 PSI.
Also, usually, using water powered backup power for sump pumps means having a lower pumping rate than electric powered sump pumps.
Additionally, these systems require a backflow prevention device and many cities require them to be annually inspected.
Zoeller 540-0005 FLEX Series Water-Powered Back-Up Sump Pump. Install it just above the sump pit.
Installation and Maintenance
Proper installation and regular maintenance are crucial for the optimal performance of your backup power system.
Natural gas backup systems will require professional installation. Which would include a gas certified plumber and an electrician.
Battery backup systems and inverter battery backup systems can be installed rather easily by a DIY installer.
Water powered backup systems will require a plumber to be installed.
FAQs About Backup Power for Sump Pumps
How long do battery backup systems provide power to the sump pump during an outage?
Battery backup systems typically offer power for a limited duration, typically ranging from a few hours to several days, depending on the battery capacity and the sump pump’s power consumption.
It’s important to choose backup power for sump pumps with sufficient capacity to meet your specific needs and consider factors such as runtime and recharge time.
Can I use any generator for backup power for my sump pump?
Not all generators are suitable as backup power for sump pumps. It’s crucial to select a generator that matches your sump pump’s power requirements.
Look for generators with adequate wattage capacity, clean power output, and automatic transfer switch compatibility to ensure seamless operation during power outages.
Can I use an inverter as a backup power source for my sump pump?
Yes, inverters that convert 12-volt battery power to 110-120 volts can be used as backup power sources for sump pumps.
However, it’s important to select an inverter with sufficient capacity to handle the surge power demands of your sump pump. Additionally, ensure compatibility between the inverter and your sump pump model to avoid any potential issues.
How do I determine the power requirements of my sump pump for selecting a backup power system?
To determine your sump pump’s power requirements, refer to the manufacturer’s specifications or label on the pump itself. Look for information such as horsepower (HP) rating or wattage.
If the wattage is not provided, you can calculate it by multiplying the pump’s voltage and amperage ratings.
Are there any specific safety precautions to consider during the installation and maintenance of backup power systems?
Absolutely! Water and electricity are a deadly combination. Safety should be a priority when installing and maintaining backup power for sump pumps.
Some general precautions include ensuring proper grounding, following the manufacturer’s instructions, and hiring a licensed electrician or plumber if needed.
When performing maintenance tasks, such as battery checks or generator servicing, always adhere to safety guidelines and disconnect power sources before working on the system.
The safest and easiest to maintain system to provide backup power for sump pumps is a water powered backup.
However, a plumber needs to install them and some cities require professional inspections every year.
Battery backup and inverter battery backups are the next safest systems that DIYers could install and maintain.
Natural gas backup systems require professional installation and maintenance.
Conclusions On Backup Power for Sump Pumps
Investing in reliable backup power for sump pumps is an investment in the protection of your basement against flooding. We’ve explored various ways to provide backup power for sump pumps. Here are the options:
Want the best? Get a natural gas electrical backup generator.
Have low water flow in the basement and abundant city water available? Buy a water powered backup sump pump.
Need to DIY install? Get a 12-volt battery powered backup sump pump.
Don’t want to buy a second sump pump? A battery and inverter backup system will power any 110-120-volt sump pump.
Those are your choices to provide backup power for sump pumps. Choose the best option that fits your needs and pocketbook.
Related Articles:
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Zoeller M53 Sump Pump Review. Best Value, Clog Free, Reliable
Author at Best Sump Pumps
The first time I helped to install a drain tile and basement sump pump system was 1978.
Since then I have worked for a city water utility where I worked with and maintained pumps.
My rental properties and personal homes all needed sump pumps.
As a modular home dealer/builder, those new homes needed sump pumps.
I put that experience to good use by providing reliable, useful, and practical advice on buying, using, and maintaining sump pumps.