Bought it May 28th, 2011. stopped working in July of 2012.Unit just shuts off about once a week. I bought this to connect to my cable TV box to prevent it from restarting everytime the power goes out for 30seconds. Had a thunderstorm the other day, power went out for 5second and this unit shut off, battery backup no longer works.Calling Tripplite tech support, its suppose to have a 3 year warranty