Apple is confirming what owners of the iPhone 4S and other iOS devices already know: The latest version of its mobile  operating system - iOS 5 - seems to make your battery lose its juice faster than before. The company now says it plans to release a software update to address the problem.

Apple spokesperson Natalie Harrison said: "A small number of customers have reported lower than expected battery life on iOS 5 devices. We have found a few bugs that are affecting battery life, and we will release a software update to address those in a few weeks."

Apple initially promised that (thanks to its power-efficient A5 processors) the 4S would deliver eight hours of talk time on 3G, six hours of 3G browsing, nine hours of Wi-Fi, 10 hours of video, and 40 hours of listening to music. But users have been complaining that they're getting far less than that, and that they're needing to charge their iPhones and iPads far more frequently than they did when they were using iOS 4.