DisplayMate creator Dr. Raymond M. Soneira tested the iPad battery and learned that the tablet continues to charge even after the battery says that it is 100% charged. Apple is saying that the iPad operates in the same manner as past iOS devices though.
The iPhone, iPod Touch, and iPad reach “100% charge” just before reaching a completely charged state. It then discharges a bit and charges back up to 100% again. This is repeated until the device is unplugged. Doing this helps maintain an optimum charge stated Apple VP Michael Tchao in an interview with AllThingsD.
?That circuitry is designed so you can keep your device plugged in as long as you would like,? stated Tchao. ?It?s a great feature that?s always been in iOS.? Tchao added that no matter where in that cycle is, the iPad can expect 10 hours of battery life that the company promises. The decision not to keep changing the status of the battery was designed so it wouldn’t distract and confuse customers. I can appreciate that decision made by Apple.