iPhone 3GS: Enable Detailed Battery Life Indicator
Here’s a nifty, new feature for those folks who are always concerned about their battery life. New for the iPhone 3GS, you can now display a percentage meter right next to the traditional battery life indicator. To enable it, head to Settings>General>Usage and flip the “Battery Percentage” switch on. Now you’ll see the percentage of available battery right next to the battery icon!
Personally I don’t leave this on because it makes me think the battery is draining faster than it used to. But hey, give it a try! If you don’t like it, just turn it back off. Enjoy!