Facebook can be a big battery drain on iOS devices. Here's how you can disable background app refresh for Facebook to prolong your iOS device's battery life.
1. Go to Settings.
2. Go to General.
3. Go to Background App Refresh.
4. Toggle the Facebook switch to the off position.
This will stop Facebook from updating itself in the background, and it will help you save the battery power of your iPad, iPhone or iPod.
An ex-Apple Genius pointed the finger at the Facebook app as a chief drain on iPhone battery life this week, as it chews up valuable minutes keeping up-to-date on various photos of lunches, skies and lunches backed by skies your friends are posting.More at The Independent
Additional resources for iOS