Nov 1 2011
A couple of days back we broke the news to you about a certain battery problem for an iPhone 4S user. The problem appears to be affecting some iPhone 4 and iPhone 3GS users as well, indicating a likely software bug rather than a hardware defect.People at iDownloadBlog seemed to have worked out a solution that may not work for everybody, even though some folks are reporting seeing an improved battery performance.
It appears that the ‘Setting Time Zone’ function in iOS 5 can lead to excess power drain because the device is repeatedly polling the user’s location in order to set the time zone based on their current location (which is useful when traveling).
1. To disable this functionality, launch the Settings app.
2. Navigate to Location Services > System Services and turn off the ‘Setting Time Zone’ option. You should see a purple location services icon in the iPhone’s status bar disappear.
Switching it off may mean that your iPhone will no longer set its own time zone when you travel, but that’s a small price to pay for having your iPhone last more than 12 hours on a full charge. We have tested this method on 4 different iPhone 4s handsets, including an iPhone 4 and an iPhone 3GS. All have reported drastically improved battery life after switching “Setting Time Zone” off.
Yes, it’s a temporary solution, at least until Apple delivers a fix through a firmware update. You may also want to disable Location-Based Aids and Diagnostics & Usage and leave only the essential system location services running (Cell Network Search, Compass Calibration and Traffic).