Recently, Apple released an update to iOS 6 for iPhone 5 and iPad Mini users only.Update 6.0.2 was released to address a wi-fi connection problem that only occurred on those 2 devices. However, it seems that, rather than curing a problem, the update has caused another one.
Some iPhone and iPad users are reporting that, since they updated their batteries have been draining faster than normal. And, it seems to be happening when the device is not being used for anything in particular or is standby, whereas, before the update, under the same condition the battery life was stable. Some are reporting a loss of between 60 and 90% of their battery life within one day without using their devices for anything special. However, as with all of these types of problems, it doesn’t seem to be affecting all users.
Apple have not made any comment but, as iOS 6.1 is due to be released soon, it probably means that they will not do anything about the current problem but will ensure it is fixed in the new release.
Here are some Tips to Save iPhone Battery .