Many users who have upgraded to iPhone OS 3.1 have observed problems with battery life. Now Apple is investigating the issue and trying to find fix.
Apple is contacting users who have reported the problem and asking them for more information. Apple is also sending users an unsigned profile to log battery life in order to troubleshoot the problem.
The users who had reported poor battery life after the upgrade are being contacted by AppleCare helpdesk and asked to answer a questionnaire of 11 questions. These questions relate to usual suspects such as email, Wi-Fi and Bluetooth and apps that are frequently used.
Apple has also made available an unsigned profile for download as an attachment. This profile enables battery life logging on the iPhone and will provide Apple with information on solving the issue.
The iPhone will sync power logs through iTunes and send them to Apple. Due to the size of the logs, Apple has suggested users to sync often and turn off battery life logging once the needed information has been collected.