Owners of the latest version of Apple's iPhone have complained that the phone's battery drains quickly, both during regular usage and standby.
Apple has not officially commented, but The Guardian reports Apple engineers are contacting users directly to gather more information about the issue with the iPhone 4S.
Apple has previously had to address issues of quickly draining batteries in its phones in 2010, when users complained after upgrading to iOS4, and in 2009, when the iPhone 3GS debuted to similar complaints.
Absent an official fix from Apple, users have found their own ways to stretch battery life for their phones, such as turning off notifications they don't need regularly. The Huffington Post has collected 10 tips to extend your battery life.