Battery issues with the iPhone 3GS have led Apple to contact some customers to get first-hand reports on what may be causing premature draining, according to users on Apple's forums and the iPhone Blog enthusiast site.
In some cases, users on the forums say the battery is draining while the iPhone is on standby. Other users say that after charging the battery overnight, it mysteriously drains after sending a couple of text messages or e-mails. Turning off features like Push Notifications and Bluetooth seem to have no effect for most users reporting problems.
Apple's support team has started contacting some customers who reported their battery problem to AppleCare, according to the enthusiast site and Apple's own forums. AppleCare is apparently asking customers to enable battery-life logging on the iPhone and then sync the logs to a computer. AppleCare is then asking customers to send in the logs, so it can try to figure out what's causing the issue.
The company apparently is telling customers that battery logging does not affect battery life itself, but that the logs do take up hard drive space. Thus, customers should plug the smartphone into a computer to get the logs off the device. This is done automatically when the iPhone is synced to a computer.
Apple representatives weren't immediately available for comment.