I just bought and received a new charger from x-treme for my xb600. Some of you might recall I posted here some time back that my existing charger was making noise...but still working. Well, it continues to work fine but I thought I'd go ahead and buy another one just in case this one quit. Anyway, so I did. The new charger looks basically the same...says on the label for 17-20ah batts/48 volts. That's correct. But, problem is it won't shut off properly and go into the "quiet" mode with the green light on and fan stopped. Both times I've tried it I know it should have cut off after about 3 hours and in once case I let it run for 10 hours and it still had not cut off. I haven't let it go to a point to damage the batts though. But, I know it isn't working also by testing it against my existing charger for the same riding and charging time. Does anyone know what might be the problem with this charger. I have a ticket in with x-treme to replace it...but still wondering why it might be defective...what may be causing it not to work properly.