I have had my iPad since late Dec. I love it and have good battery life; I usually charge it once every couple of days, then put it into sleep mode overnight. In the time I've had my iPad, it only drops about 2% when I do this overnight. I also completely run down the battery once a month (as suggested by Apple), then charge it back to 100%.
A couple of evenings ago, I put my iPad into sleep mode when the battery was at about 50%. When I turned it on the next morning, it was down to 30%. I thought that this must be a fluke. So I charged it overnight, and it was 100% this morning. I put it into sleep mode and left it home when I went to work. When I turned it on about 2 hours ago, it was down to 80%!
I would appreciate any help regarding this. Something is obviously going on, but I have no idea what!