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
Go Back and Forth Fast in Preview
If you're reading a PDF in Apple's Preview software, and you follow a bookmark or an internal link to move around within the PDF, you can quickly return to where you were by pressing the keyboard shortcut Command-[ (that's Command-Left Bracket). Or, you can choose Go > Back.
The command works iteratively, so you can go back to just the previously viewed page or if you issue the command again, to the page before that, and so on. There's also an equivalent Go > Forward (Command-]).
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?