How do I use my iphone? Is my battery dying and ripe for replacement? Would it make sense for me to get an external battery pack? BatteryLogger Lite answers these questions and more by logging the battery-state on every change, and presenting the results in graphical plots. In contrast to the only logging program currently in the app-store, BatteryLogger has been designed for efficiency and scalability, allowing to store a virtually unlimited amount of datapoints, and view results for any period.