they bench tested the first one when I had to bring it back, and it was putting out 13vs not 13.8, 13 and I said shouldn't it be about 13.8-14+ and they said no it should still charge, then I figured out I know more then they did (I know some about charging systems but not all) that why I'm going to try Advance. I would try to rebuild my old one but I don't have time to wait.