With well over 4 million iPhone 4S units sold over the first week of release, some owners are reporting that battery life is inexplicably short with normal usage. Even compared to the iPhone 4 and iPhone 3GS, for some reason the new design is sometimes experiencing power drain for no apparent reason. According to the Guardian, Apple engineers have begun to respond to iPhone 4S owner complaints and many have installed diagnostic software to help track down the issue.
One of the unannounced iPhone 4S surprises was a shortening of the standby time on the device to 200 hours down from the iPhone 4 spec of 300 hours. There was no wave of concern over this number, until the iPhone 4S started losing battery power at a much faster clip in some cases. Initial reports of shorter than expected battery life have evolved over time into serious battery drain problems in some cases.
Already, the issue seems to be related to corrupt contacts imported from MobileMe or iCloud, or possibly Google Contact lists. Some users have reported that deleting and reinstalling the contacts fixes the battery drain. Typical battery-saving solutions such as turning off 3G data has some effect according to tests by the Guardian, however Siri, location services and Wi-Fi usage had no impact on battery life.
Despite the reported problems, the iPhone 4S is equipped with a slightly more powerful battery than the iPhone 4, with 0.05Wh more capacity than the previous model. The hardware also includes a more power-hungry dual-core A5 processor and a more demanding iOS 5 operating system. Battery problems are not a new issue for iPhone owners, as several firmware updates have resulted in swift power drain that was later identified and corrected by Apple updates. Presumably once the diagnostic software does its job Apple will be able to issue a firmware update to fix the source of the battery drain and bring all iPhone 4S owners back into expected battery life range.