I agree.. the iPad won't let you overcharge it, when it gets to a certain point it cuts off, I also doubt that adding a extra 1 or 2 hours beyond the point where it reaches 100% is actually putting anything into the battery. However I have noticed that when fully charged to 100%, it does seem to fall from that 100% very quickly indeed, on mine after just 2 or 3 mins use it will show 99%, whereas my older iPad stays at the 100% mark much longer... though in fairness, I should add it will only have fallen to around 94/95% after 1 hours continual use.