The unit has been in my basement sump for a month. The primary pump is very powerful and quiet. Have had no reason to use the battery operated back up pump. Upon installation, a problem with the battery box controller occured. The self test failed, blew the 20amp fuse. The company was contacted and a replacement controller was ordered. After the company got my address and name spelled correctly, the controller arrived and was installed. The self test worked. The big test will be when the hydro (electricity) fails.