In iOS 8 you can now see which apps are using up your battery the most. You can check by going to Settings -> General -> Usage -> Battery Usage. On this screen you can see by percentage which apps have used the most juice in the pas 24 hours or last 7 days. It also shows you how much time you have spent using the iPad since its last full charge and how much time it has spent in standby.
How do I see what apps are draining my iPad's battery?
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