According to tuaw.com:
is all kinds of sexy, but with a slew of fancy new features comes more strain on the ever-important statistic of battery life. iOS 7 is compatible with iPhone 4 or later (though not all features are supported on older devices), so if you’re upgrading your current device to the new operating system, there’s a good chance you could see a noticeable decrease in battery life.
If you’re looking to avoid any pitfalls in the battery department, here are a few settings you can tweak to keep iOS 7 from sucking your iPhone’s life like an evil, software vampire.
Disable background refresh
iOS 7 lets certain apps refresh even when you’re not using them, which is both super convenient and a big problem for users who want the most out of their batteries. Disabling Background Refresh entirely would be your best bet, but even disabling the feature on just a few apps should help your device remain lively for a bit longer.
Alter your location services
It seems like just about every app wants to track your location these days. For some apps, like Maps, this makes a lot of sense, but if you’ve authorized other apps (Twitter, Facebook) to track your location without actually using the in-app features that go along with it, you should turn it off. In addition to apps, iOS 7 has a whole host of system-level options for location tracking, including local advertising and even the compass. If you don’t use the apps to begin with, turning off the GPS tracking won’t do much, but if you can disable tracking for a few of your most-used apps, you could see a decent boost in battery life.
Not using AirDrop? Kill it
iOS 7 introduces AirDrop to the iPhone for the first time, but even if you find yourself using the handy Dropbox-style feature from time to time, you should be turning it off when you don’t need it. This is made easy by the new Control Center in iOS 7, which can be brought up by swiping upwards on the home screen. From here, it’s just two taps to either enable or disable AirDrop, and while you’re here, you can also disable Bluetooth and/or WiFi to help save additional battery life when you’re not using them. Note: AirDrop is not available on the iPhone 4 or 4S.
3D goes bye-bye
OK, this one is going to hurt: You know that fancy 3D parallax wallpaper effect that iOS 7 introduces? Unfortunately for users who want the most out of their battery, it’s a luxury that does nothing but burn power to make your home screen look cool. You can disable this feature by toggling on the “Reduce Motion” option in the Accessibility menu.
The same goes for the new dynamic wallpapers. Yes, a moving background image is a pleasant bit of eye candy, but it serves no functional purpose other than shortening your time between charges. Kick these features to the curb and your battery will thank you.