I had the batteries replaced in two I pad 2's yesterday. One charged fine, and the other one will not go above 40%. I am using the original wall charger and cable that came with the I pad for charging. I plug it in like always, and it shows it is charging by the green light on the display. When I plug the charger in the I pad comes on. After many hours it is still showing only 40% charged. This is where it was when I got it back from the guy that changed the battery. I unplugged the charger and restarted the I pad hoping it would show a higher battery percentage, but it didn't. Any ideas what could be the problem and how to fix it? Any help would be appreciated.