Following the update to iOS 5, and in response to reports of high battery drain from iPhone and iPad owners, Apple is said to be close to releasing a fix for the issue. I've started experiencing the battery drain issue on an iPad 1 and have intentionally kept my iPad 2 on iOS 4 until the fix repairs the problem.
The iPad 1 running iOS 5 is losing about 10% a day when in standby. There are no apps running in the background and its iCloud services are turned off, which should help, but the problem is still there. The iPad is a notoriously power-efficient device and it would normally lose about 1% in standby mode on a typical day. The only other time I've experienced such a high battery drain is when the iPad was tethered to enterprise systems and constant background data communications were taking place.
Hopefully the forthcoming update will help to solve the issue!
