Apple is investigating reports of poor battery life problems from iPhone 3GS users after they upgraded to the 3.1 OS. The iPhone 3.1 software update delivered many new features, but some users also report that the phone's battery life is severely and adversely affected.

Apple's support forums are now overflowing with complaints from iPhone 3GS users who updated their phone to the 3.1 software. The messages on the forums are all so familiar -- extensive battery drain in a very short space of time. More than 375 replies are now on the respective thread.

Following the river of complaints, Apple is reportedly taking steps to address the poor battery life problem. The iPhone blog is reporting that some iPhone users are now being contacted by AppleCare helpdesk representatives with a list of 11 follow-up questions focusing on batteries.

Apple is also offering for download an unsigned battery life logger, which will collect information about your phone's battery life. The logger syncs the data with iTunes to send it to Apple for investigation.

Troubleshooting iPhone's battery problems

Push or Exchange e-mail, Wi-Fi, Bluetooth, and various App Store applications can deteriorate your iPhone's battery life, according to various Apple Support reps I have been speaking to.

Like some of the replies on the Apple support forums, Apple support staff suggests that if you experience problems with your iPhone's battery life you should restore your phone from iTunes. However, plenty of users are reporting that this solution doesn't work in all cases.

I have also experienced in the past battery problems with both the iPhone 3G and 3GS after updating the OS software, and a plain restore of the phone did not solve it. But after extensive calls to Apple Support, I managed to get the battery back on track only after a fresh download of the iPhone OS onto my computer and then restoring a new phone using the new software.