On 27 Jan 2006 17:37:08 -0800, "
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.

there are also water powered back up sump pumps if your on city
water.....

I recently talked to someone that has city water, and it quits during
a power failure.