I updated my mother's iPhone 5 and my Air to iOS 8 and both have the same battery life or better than before (in the case of her iPhone).
However, after the updates I closed all open apps and then I forced a shutdown by holding down the power and home button. I dunno if that's done anything but I always do it after an update to nip battery drains in the bud.
However, after the updates I closed all open apps and then I forced a shutdown by holding down the power and home button. I dunno if that's done anything but I always do it after an update to nip battery drains in the bud.