10-07-2010, 08:58 PM
Doc wrote:
...
I was under the impression that -- excepting music players -- when location services and notifications were off iOS 4 essentially reduced their CPU use to zero when they weren't in the foreground.
iOS can reduce an app's CPU use to essentially zero, but doesn't unless it needs to in order to run something else you requested later.
Doc wrote: Should I restart it to end all of those processes before I sleep it? That'd be very annoying. This thing takes a full minute to boot.
No, but you can kill them manually without doing that.
From Lifehacker (and other sources)
"To remove an application from running in the background, just pull up your quick switch drawer (double-tap the home button), then tap and hold on an app (like you do when you want to delete an app from the home screen until you see a red minus sign (-) on the corner of the app's icon. Tap it to kill the app."
And there are non-sanctioned apps for jailbroken phones that have different methods for managing running apps.
But remember what I said above about how an app runs in the background (my Navigon example). It's not so much a running background process that kills the battery, it's what the app is DOING in the background that might kill the battery (which is why killing it might result less anguish if it's not clear what it might be doing.)