First off I will give some background info so you realize where I will use this info if you do find it. I work in the cell phone industry and am accountable for support documentation. In fact I write a lot of it for people (unlike you XDA'ers ) who call in to the carriers.
I am exploring an issue where data is being used on devices with autosync settings turned off. I'm looking at a pattern of about 10MB over 9 hours. The data is being tracked using 3G watchdog pro. The application that is using data is the Phone app.
Devices being affected by this issue include GSII's HTC Sense 3.X devices, Galaxy Tab (original) and more. It appears to only affect Gingerbread ROMS.
I am trying to understand the whats,wheres and hows of this data usage. I have some theories:
So the dialer is using up data because it is being accessed (no longer under the purview of “Autosync”). From that point it is syncing contacts as well as images for those contacts.
I’m not one hundred percent about this but I believe that social networks being tied into the device could possibly sync their contact data through phone instead of the app itself. For example, access facebook and dialer shows the sync data through Phone. MMS can also use data here as well.
Do you guys have any input into whether I am on the right track?
All devices are non rooted stock and are customer devices I don't have access to...
OK and now as preemptive payback to the community here a small (vetted and certified) excerpt around batteries.
Batteries at 100% charge will lose their maximum possible capacity at a rate of about 20% per year. Even if the battery is not plugged into the device and is inactive, the maximum capacity will be damaged by this 100% idle status.
I thought that keeping a battery at 0% charge was damaging to the battery?! Now you are telling me that 100% is damaging as well?
A battery at 0% will lose capacity and be damaged at around the same rate, or even faster than a 100% charge. The good news is that all modern cell phone manufacturers take away your ability to run your phone down to 0%. In fact when your phone dies and you assume your battery life is all gone, the reality is that you are at about 20% battery life. This is the safety buffer to protect your battery life.
What are the best practices for battery maintenance?
Well, it’s not super easy for many users. One of the main things you can do is not put your phone on a charger overnight. Although most manufacturers will lower the voltage down to a trickle when it is almost up to 100% you are still bouncing up against your maximum capacity. Best practice is to have multiple chargers for wherever you go. Charge your phone on the way to work. Charge it at work. Charge it as often as possible without idling at 100%.