In order to choose a sump pump battery backup, the first thing you should do is assess your needs. Here are some of the biggest factors that will play a role in your decision:
Are you trying to protect the contents of your basement (Is your basement refinished? Is your furnace or water heater on the floor or raised? Do you store anything in your basement, or is it empty?)
How often do you experience power outages? (A few times a year? Rarely? And do you have an automatic generator?)
How often do you experience flooding in your geographic area? How does the position of your house contribute to basement flooding?
How old is your current sump pump? (Was it recently installed, or is it approaching the end of its 10 year lifecycle?)
The answers to the questions above will help inform your decision. The more at risk your home is for damage, the more protection you will need from your system.
When it’s time to choose a sump pump battery backup system and you begin doing research, you will probably realize that there are two basic methods being offered on the market today. In order to fully understand which system will meet your needs, you need to understand the differences between them.
The first, and most conventional, type of battery backup is a secondary, battery-operated pump installed as a redundancy to assist the main basement pump. These are often sold as packages that contain a DC-powered auxiliary pump, a battery, and a charger. The secondary pump is installed in the sump pit along with the primary pump.
PROS: The main goal of the secondary pump is to assist the first in case water levels rise beyond the capabilities of the main pump. To achieve this redundancy, the float sensor on the secondary pump is mounted above the level of the sensor on the main pump.
CONS: The most important feature of battery backup systems is that it provides protection if the power goes out. However, if you have a DC-powered secondary pump and the power does go out, the backup pump stops playing a support role and starts doing all the work. This can cause major problems, because the secondary pump is usually not as powerful as the primary pump and will not be able to match the capacity needed. Paired with the smaller battery and limited backup time provided by the system, and you could be facing a wet basement despite your attempts to be prepared.
The second method of sump pump battery backup is a power converter/control system designed for wall mounting and used in conjunction with a battery or battery bank.
PROS: Unlike auxiliary pumps, this type of pump is not intended to replace or supplement the function of the main pump. Battery backups allow the main pump to seamlessly continue functioning at full capacity if the power goes out. This system also does not take up any additional room in the sump pit, doesn’t require the installation of any additional pumping equipment, and has a long life.
CONS: The only real con to this system is that, if the pump failure is mechanical and the pump itself is broken, the battery backup may not activate.
Both of these systems are available on the market today. Weigh the pros and cons of both options, and be sure to take the condition of your basement into consideration before making a decision.