Apple will make the iPhone Battery Logging-profile available for its customers who complain about the battery life of their device, according to information on the website of HardMac. The user installs the profile and after that all usage of the iPhone will be monitored over a specific amount of time.
Support staff can than later determine what the cause of the quick reduction of battery energy was. Then it will also become clear if the battery is defect or if the user just used his iPhone a lot.
Almost all usage will be monitored. From starting up an app till the usage of Wi-Fi. People seem to use their iPhone as a computer very often: they use the internet, play games and call friends, causing them to recharge the iPhone after only a few hours.