DIYbanter - View Single Post - Questions - Battery Back-up Sump Pump

wrote:
"batery will need replaced every 2 to 3 years no matter what you do. by

4 years the batterys capacity will be small., that is run time will get

shorter and shorter. "

And why is that? Even a car battery lasts 5-7 years. Lead/acid
batteries will last a long time if kept properly charged. The killer
is the number of times they are discharged. Even worse is to discharge
them and leave them that way for an extended period. If used for
emergency stanby, a battery will last a very long time. Just ask the
phone company. They have huge banks sitting there to power the phone
system during a power failure.

From full charge to discharge would the pump immediately begin to slow
down (less gpm) or would it maintain its full capacity to pump until the
battery power got to a certain level? What I mean is, if the battery
was 1/2 discharged, would the pump only pump 1/2 the volume of water?

Sorry of these seem like pretty basic questions, unfortunately
electricity is not one of my strong points.

Keith