Poor Battery life after iOS 5 update

After my upgrade iPad 2 to iOS5, I noticed the battery life was less than half of it's normal operating time. Normally my iPad 2 would drain just a few percentages, but now battery life is definitely much shorter. I fully charged it today to test it, After 3 hours, I got the "you have less than 20% battery remaining" warning. A small number of iOS 5 users have had the battery life issues. Apple