In this tutorial we will guide you on how to check background usage of a particular application on an iPhone using a specialized utility. Called the BatteryDetective, it can detect battery consumption done by a particular app. The consumption is then shown shown on the screen. For instance in our case, we wanted to check how much the default media player consumes and the answer was 116mA.
BatteryDetective is a very neat iPhone application. BatteryDetective has the ability to test the amount of battery drain that Background Applications are pulling. Not only that, BatteryDetective also allows you to test how much battery different iPhone settings use. Paired with SBSettings (not required) it makes a nice tool to see where your battery life is going.
BatteryDetective also provides precise details about your battery real time, more than you can find anywhere else. Only compatible with iPhone 3Gs, iPhone 4, iPad and above.