20% and 10% warning last longer?

Discussion in 'iPhone' started by rotobadger, Jul 15, 2008.

  1. rotobadger macrumors 65816

    rotobadger

    Joined:
    Sep 18, 2007
    #1
    This is not intended to open a new debate/complaint about the battery life of 2.0 rather to point out something interesting I've noticed. While the battery has been draining much faster than V1 iPhone (and yes, I have Push, location services and 3G all turned off) I've found that the time interval between 20% and 10% warning is much longer than my old iPhone. Does everyone remember this? "Warning! 20% battery left". Then, like 5 minutes later comes the 10% warning. Not the case here. I must have gotten nearly and hour more of usage from the 20% mark all the way to shutdown. For V1 it was more like 20 minutes (if that).

    Anyone else notice this?
     
  2. Badandy macrumors 68040

    Badandy

    Joined:
    Sep 29, 2005
    Location:
    Terminus
    #2
    The battery life, with all the 3G and GPS and wireless stuff turned off, should be better than the first gen iPhone. But that's besides the point:


    I have noticed this as well. I got an hour of video watching after the 20% warning.
     
  3. FearlessFreep macrumors 6502a

    Joined:
    Jul 15, 2008
    Location:
    Northern Virginia, USA
    #3
    I don't think this is merely coincidence.

    I honestly believe there is a problem with the calibration of these Li Ion "smart" batteries. Smart batteries report their power state to the device. The amount of charge may remain constant, but what the battery reports may be radically different:

    "Repeated short discharges and recharges cause increasing inaccuracy between the state-of-charge of the battery and the Power Meter readings. Periodically, the battery needs to be calibrated to "relearn" its usable capacity so it can synchronize its charge status with the Power Meter. "

    Something is amiss with the battery: either it is inaccurately reporting the amount of charge, and/or it is not setting the charger with the correct algorithm.
     
  4. rotobadger thread starter macrumors 65816

    rotobadger

    Joined:
    Sep 18, 2007
    #4
    So, in your opinion, is this an issue with the battery or can it be fixed with a software update?
     
  5. dmblue macrumors member

    Joined:
    Jun 18, 2008
    #5
    i totally agree..

    i was just using mine and i had everything on except for location services..

    i noticed that it doest last longer.


    i think alot of the people who are bitching about their phones havent given it a good charge yet..
     
  6. FearlessFreep macrumors 6502a

    Joined:
    Jul 15, 2008
    Location:
    Northern Virginia, USA
    #6
    Not an EE so I honestly couldn't tell you.

    It's rumored that Apple used a smaller capacity battery than the first gen iPhone. The 2.0 software is obviously ported from 1.x lineage, so it is possible Apple forgot to change the power meter algorithm for the 3G model. Logic would dictate that if the software assumes a 1400 mAh battery and a 1150 mAh battery is actually powering the phone that the power meter would not report accurate charge states. In fact, if the software is expecting a higher charge state to begin with, it stands to reason that a lower capacity battery will appear to discharge more quickly using the algorithm for the larger one (at least that makes sense to me, but again I'm not an EE and perhaps someone who is will correct me).

    IF that scenario is true, however, then a software fix would solve the problem. If the problem lies with the battery itself and how it's reporting to the device, then the battery would have to be replaced.
     
  7. rotobadger thread starter macrumors 65816

    rotobadger

    Joined:
    Sep 18, 2007
    #7
    God, wouldn't THAT be a mess!

    Also, if I understand you correctly, it's possible that the battery isn't bad (maybe it is maybe it isn't) it's just that the iPhone is not calibrated correctly. So when your phone "dies" it is not because the battery is completely drained it is because the phone thinks it is...and shuts down.

    Is that correct? I'm actually learning something in this thread!
     
  8. Bernie-Mac macrumors 65816

    Joined:
    Jul 30, 2007
    Location:
    Sin City, NV
    #8
    Maybe that is what 2.0.1 is going to correct?
     
  9. nickspohn macrumors 68040

    nickspohn

    Joined:
    Jun 9, 2007
  10. rotobadger thread starter macrumors 65816

    rotobadger

    Joined:
    Sep 18, 2007
    #10
    Also, on my V1 battery would show 100% for about 1.5 hours. Now it moves to below 100% after about 45 minutes.
     
  11. elbirth macrumors 65816

    Joined:
    Jan 19, 2006
    Location:
    North Carolina, US
    #11
    something I noticed after either the 20% or 10% warning, is that when I tried launching 3rd party apps, they would all close and take me back to the home screen. I could only load and actually use official apps. I'm not sure if that's a "feature" meant to save battery for phone calls when it's getting low or what, but I found it pretty odd
     

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