Apple iPhone 4S users say iOS 6.1.1 causes battery drain41
battery life has been awful and the handset has been running hot. One iPhone 4S user reports that his battery life has dropped since the update from 7 hours to 5 hours while another reports that battery life on his iPhone 4S has dropped to 4 hours since the update. At least the connectivity issues seem to be repaired!
Besides the initial problems that were discovered with iOS 6.1 for the Apple iPhone 4S, other bugs have been discovered with the OS build such as the inability for users to sync with Microsoft's Exchange email service, and another that allows anyone to break into your Apple iPhone even if locked using a passcode. So we should see another update to take care of those problems with iOS 6.1 and the new battery issues that have sprung up on iOS 6.1.1. Apple is said to be aware of the problems which is at least one step in the right direction. Stay tuned!
source: AppleSupportCommunities, Wired via CNET