Scotty Loveless, a former Apple Genius, has posted the best guide we’ve seen to solving iOS battery drain. Unlike many guides that tell you to turn off every feature, Loveless offers a more targeted approach, including instructions on how to test battery drain and specific suggestions that are likely to improve battery life. Two surprises: the Facebook app is a huge battery hog and quitting apps may hurt battery life. follow link
Untrash the Trash
Feeling trasher's remorse? On Snow Leopard, you can open the Trash (click the Trash icon in the Dock) and "untrash" individual items there. Select one or more trashed items (files and folders) and choose File > Put Back. This returns the items to where they were when you originally put them in the trash. The keyboard shortcut is Command-Delete - the same as the shortcut for trashing an item in the first place, since in deleting something from the trash you are untrashing it.
The Ultimate Guide to iPhone Battery Drain
I could see that my wife's iPhone 4S was never sleeping (Usage and Standby times were equal). GREAT! I finally had a diagnosis of the problem.
How come this advice is not better known?
But, Apple offers no insight nor tools to help fix this.
Force quit every app - nope. Restarts - nope. Upgrade to iOS 7 - nope. More Restarts - nope. Turn off Location Services - nope. Turn off Background App Refresh - nope. More force quits - nope. Install Battery Performance Monitor apps - nope.
So now what?
Installing System Activity Monitor app helped, but the savings finally came from deleting an old Mail account which obviously was caught in a loop.
Surely Apple could give tools to identify issues like this earlier?