“Android OS” Battery Usage can be Caused by Background Data

I’ve been performing more experiments to try to decode the mystery of what uses the battery on my Android phone.  I love that Android gives me the battery usage info and the graph of battery usage over time.  That gives me the tools I need to experiment.

The “Battery Usage” screen (Settings>About Phone>Battery Use) now says “Android OS” is the thing using the biggest percentage of the battery (See the picture).  Apparently the thing using the Android OS is apps using “Background Data”.  When I turned off “Background Data” (Settings>Accounts&Sync), I saw a vast improvement.

When Background Data was on, I left the phone sitting idle and saw the battery draining at 4% per hour*.  So, over one day: just unplugging my phone at 6am and not using it until 6pm, half the battery power was gone.  So, if I used the phone during the day at all, it wouldn’t last past dinner.

When I turned off Background Data, the battery drain went down to 1% per hour.

Apparently some apps are “calling home” very often to check if my opponent moved or if there are new messages.  I try to use apps that give me control over how often they check for stuff like that.  As I recently posted, the Yahoo! Mail app was calling home way too often and it’s use showed up as using the Dialer. Both of these point to a need for a better Push Notification system for Android.

More difficult will be figuring out which of my apps is the one using so much Background Data.  The only way I can imagine to do this would be to uninstall one app at a time and watch the battery drain for a couple hours each time.  This could take weeks.

* Don’t confuse my reported 4% per hour battery drain with the percentage shown in the picture.  I really do mean that the battery power went down 4% each hour.  This, of course, has nothing to do with the percentage shown in the battery usage screen (in the picture).  The “battery usage screen” shown above tells you that 56% of the battery power that’s gone was used by Android OS.  This has nothing to do with the battery usage drained per hour.