09-24-2013 11:43 AM
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  1. infinidim's Avatar
    The more I observe my 820, the more I am convinced that the battery indicator either reads high by about 5% or perhaps rounds up by that amount. If I take the phone off charge as soon as it declares it is at 100%, the battery indicator starts falling right away. However, if I leave it on the charger for another hour or two, the battery indicator stays at 100% for between four and five hours.

    Yesterday, I received the replacement battery that Nokia sent me and installed it. It reported 67% initially. After charging for a while, the DT-900 LED turned off. I left it on charge a couple more hours and then started observing it. In standby, the battery indicator stayed at 100% for the rest of the evening (about four hours). Overnight it dropped to about 95% in a total of about 11 hours since it came off the charger. If I assume that the battery indicator either rounds up by 5% or simply is 5% off, that comes out to 5% plus the 5% error for a total drain of 10% over 11 hours, or a discharge rate of about 1%/hour.

    Next experiment will be to switch my Google account from manual updates to every two hours and see if that impacts the battery life.

    Paul
    Paul,

    The more information we gather on this forum the better I think. Currently my view is that it is a bug in the Windows Phone OS. To me it looks like a process that sometimes takes a lot of battery power. I can only fix it by powering down my phone and restarting it again. That seems to fix it for sometimes a day or two then it comes back - I then go through the whole process again.

    The battery level problem is interesting. What I believe happens is that the battery apps call a Windows Phone system call, method or API to get the current status of the battery. The Windows Phone OS would then make a call to the firmware to get the status, so this issue could very well be with the Nokia firmware not returning the correct data. I have tried a number of battery apps now and they all seem to have the same issues. Just a thought.

    These issues are very complex and multi layered - it could be an application, the Windows Phone operation system, the firmware, the phone silicon or even the battery could have the issue. Gut says it is not the battery or silicon currently.

    Lets hope we find it soon as it is annoying.
    09-22-2013 07:49 AM
  2. pgoelz's Avatar
    Agreed! And yes, I think we have at least two different issues here.

    The battery indicator (at least on my 820) DOES read high by about 5%. This distorts the percent use per hour figures and can cause you to take it off charge prematurely.

    There is also clearly an issue with something getting stuck and causing excessive battery drain. I have seen mild examples of this, where my discharge rate would run about 4%/hour even with the phone in stand by. After uninstalling most optional apps and leaving cell data and GPS off, I now see a consistent (so far) discharge rate of about 1%/hour. I am gradually re-adding the few apps I really want and observing the battery performance.

    To date, I have not had the extreme version of this where the phone gets warm. In fact, it has NEVER gotten warm, even while watching a streaming video.

    Paul
    09-22-2013 08:18 AM
  3. pgoelz's Avatar
    More experimenting...... yesterday I installed Here Drive and Gas Buddy. Both created background processes and my standby battery consumption rose to approximately 2%/hour. This morning I blocked both background processes and the battery consumption appeared to remain at 2%/hour in standby. I then uninstalled both apps and restarted. We'll see if my standby drain comes back down to 1%/hour or less.

    Preliminary results seem to show that simply blocking background processes does NOT make the phone act as if there were no apps installed that want to consume resources while the phone is in standby. This would also explain why battery saver did not seem to have much effect. Trouble is that without access to system information, it is very difficult, innacurate and time consuming to figure out what is happening.

    Paul
    09-23-2013 11:04 AM
  4. edwardtkl's Avatar
    My 820 is discharge at a speed of 5% per hour, with the following features turned on

    4G, bluetooth, location service, 4 background services, glance screen, double tap to wake
    09-23-2013 11:42 PM
  5. pgoelz's Avatar
    More experimenting...... yesterday I installed Here Drive and Gas Buddy. Both created background processes and my standby battery consumption rose to approximately 2%/hour. This morning I blocked both background processes and the battery consumption appeared to remain at 2%/hour in standby. I then uninstalled both apps and restarted. We'll see if my standby drain comes back down to 1%/hour or less.
    And the answer.... yes, it did come back down to 1%/hour or a bit less after uninstalling Here Drive and Gasbuddy. I have re-installed Gasbuddy, blocked its background process and then rebooted. Testing now to see if the discharge rate remains at 1%/hour. Decided I can do without Here Drive for now.

    Paul
    09-24-2013 11:43 AM
30 12

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