This will hopefully help others who may encounter the same issue I did with my batteries for my two phones. One worked great and the second didn't work right at all. The hassle of returning them was more then the batteries cost so I decided to use my superior skills at deduction - just call me Sherlock. One of the contacts was siting a little too low to make contact with either the charger or the phone except for rare instances which caused erratic behavior. The difference was VERY slight. The black holder snapped apart easily and I slightly bent the contact. Now they both work great. What do you expect for the very cheap price but a little lower quality control so don't complain!