Developed by Hans Einstein, BatteryLife does not use the theory of relativity to speed up your mobile web browsing, but it does manage to tell you how much power you have on your iPhone. The application boasts a warm UI with appropriate indicators for everything you need to know about how much life your iPhone’s battery has, and even to isolate those apps that eat up most of your battery.

The application displays the battery charge in percentage and graphic information and gives the charge percentage of the battery the last time you used the application. You are also shown the exact date and time of your last verification, as well as for how long the device stayed plugged to a power source. For the latter to take effect, you must charge your device with BatteryLife running.

This is where the LED indicator comes in. Situated at the bottom right side of the screen, the LED shows by colors (orange, green and red) whether the battery is being charged, full or if there is no power source charging it at the time of checking. The “i” (information) button allows you to configure the app to show these aspects of your battery life as you like.

BatteryLife can also be used to track just how much battery power some applications or processes use up on your device. For example, I fired up Safari on my first-gen iPhone to browse the web for about 10 minutes starting with a 90% full battery, followed by a quick game of BackGammon. Then I launched BatteryLife again to see how much of my battery was drained. It immediately indicated a 10 percent decrease, as shown below.


Looks like the iPhone 3G S isn’t the only device plagued by OS 3.0-battery drainage

Adding to the list of benefits, BatteryLife is freeware, which means you can download and use it for free, for as long as you like. The app requires an iPhone (any model) or an iPod touch (second generation only, says the iTunes description), as well as the latest software version from Apple - iPhone OS 3.0 (ironical, isn’t it?)

Download BatteryLife via iTunes (Free)