Battery Backup For Sump Pump       

Battery backup for sump pump is not needed if you have a municipal water supply. A water powered backup system would be the better choice. The best use for a battery powered sump pumps would be country locations or weeping tile septic systems where you have no municipal water supply.

In any case if you consider your sump pump as a critical component to the safety and well being of your house or business then a back up sump pump should be a priority. If you have a main pump failure a  backup sump system is cheap insurance compared to the damage that can occur from a pump failure or flooding from any cause.

If you live in areas where you have a low water table or the ground water is seeping continually a back up sump pump system would protect your dwelling from any number of things that could cause a pump failure. So if you need a battery backup for sump pump which type of system and what kind of battery is best?

Ideally you would want a backup sump pump that has enough power to equal the first or primary pump. A backup pump system of equal power would double the water capacity removal, one unit that has this feature plus comes on automatically in the event of pump failure is the Zoeller 507 battery backup sump pump.

What Kind Of Battery?

A deep cycle battery is the perfect choice. These batteries can sit without losing a charge and  are designed for charge discharge cycles without losing the capacity to hold and keep a charge. A  lead acid based car or a marine battery is the battery of choice for cranking power to start an engine. For backup sump pump installations it is not recommended. Car and marine batteries are not designed for this purpose. 

How Much Pump Capacity Do I Need

 Look at your particular siituation to determine the right sump pump backup. The best would be a pump equal to your main pump capacity.

Your locale where your building is located, low or high ground?
History of storms or other events that produce excess water
Is it mostly seasonal when flooding or high water levels occur?

How Much Lift?

The next thing to determine is the height of the lift required to remove excess water. Assuming your present sump pump is properly sized for the height of lift, the same rule applies for back up. A sump pump can remove much more water at a 6 ft lift than it can at 12ft. The pump lift rating is usually found in the pump specs. See Zoeller sump pump for information about zoeller sump pumps. 

The best way to determine the proper back up lift for the backup sump pump is to at least match the lift requirement to that of the main pump. The pump capacity needed could be illustrated by this example. A sump with an 18" diameter and a water rise of 6" per minute indicates 420 gallons of water an hour (Canadian equivalent add 20%). Just to be safe add 50% to that estimate and size accordingly.