Battery capacity lost 400 mAh overnight?

Discussion in 'MacBook Pro' started by GP20, Feb 15, 2014.

  1. GP20, Feb 15, 2014
    Last edited: Feb 15, 2014

    GP20 macrumors member

    Joined:
    Oct 3, 2012
    #1
    I have a late 2013 2.3ghz retina 15 purchased about 2~3 weeks ago. I use Coconut Battery to track the battery performance. Since I've had it, the battery had been consistently in the 9100~9200 mAh range. But suddenly today, the total capacity lowered to 87xx mAh overnight.

    Anyone know the reason for this? Does that mean something's wrong with the battery?
     

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  2. NukeIT macrumors regular

    Joined:
    Mar 20, 2013
    #2
    Use it more. Worry less.

    The battery capacity will fluctuate over time. If you are going to analyze it. You need more data points to show trends vs a snapshot in time.
     
  3. Macman45 macrumors demi-god

    Macman45

    Joined:
    Jul 29, 2011
    Location:
    Somewhere Back In The Long Ago
    #3
    I've never seen such a big jump, bug I still wouldn't worry, just charge normally.

    If you want to reset the battery meter, perform an SMC reset, then charge:



    http://support.apple.com/kb/ht3964
     
  4. simonsi macrumors 601

    simonsi

    Joined:
    Jan 3, 2014
    Location:
    Auckland
    #4
    More likely an algorithm in Coconut Battery.....either way just use it as a rough indication until your actual battery life starts to decay....
     
  5. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #5
    Your battery is fine. It is perfectly normal if your battery health (maximum capacity) is more or less than 100%, even when brand new, or if it fluctuates up or down over time. The gradual decline is not in a straight line downward, and it may decline more rapidly at some times and slower at others. For further details, read the CHECKING STATUS AND HEALTH section of the following link.
    The link below should answer most, if not all, of your battery/charging questions. If you haven't already done so, I highly recommend you take the time to read it.
     
  6. alphaod macrumors Core

    alphaod

    Joined:
    Feb 9, 2008
    Location:
    NYC
    #6
    It's still more than design capacity.

    And do a battery calibration to see if it helps.
     
  7. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #7
    The built-in batteries in the newer Mac unibody notebooks come pre-calibrated and do not require regular calibration like the removable batteries in older Apple notebooks.
     
  8. GP20 thread starter macrumors member

    Joined:
    Oct 3, 2012
    #8
    Thanks for the replies! I definitely appreciate them.

    The battery capacity is now down to 85xx mAh and really struggles and go over a slight bit over 8600 mAh at times. So it lost about 600~700 mAh in a matter of 2 days. I realize that the battery capacity usually fluctuates a bit, and I'd be fine with that as long as the battery life deteriorates normally. But 600~700 seems way to drastic.

    As far as the battery calibrating itself, I thought the rMBP's battery came pre-calibrated from the factory? And especially since it already had 12 cycles when it was consistent at around 9000~9200. Then literally out of nowhere, it took a huge dive.

    I've already done SMC reset a few times, and even did a fresh install of Mavericks. So far nothing has improved.
     
  9. simonsi macrumors 601

    simonsi

    Joined:
    Jan 3, 2014
    Location:
    Auckland
    #9
    TBH I would address the concern to the Coconut Battery developers.
     
  10. thundersteele macrumors 68030

    Joined:
    Oct 19, 2011
    Location:
    Switzerland
    #10
    IMHO you should stop wasting your time worrying about a battery that has over 100% capacity.

    I don't know what fluctuates more, the capacity itself or the estimate of the capacity that the OS does, but between those two, there is absolutely nothing to worry about.
     
  11. jonesea macrumors newbie

    Joined:
    Dec 21, 2013
    #11
    Temperature also has an effect on battery measurements.
     
  12. gngan macrumors 68000

    gngan

    Joined:
    Jan 1, 2009
    Location:
    MacWorld
    #12
    +1. Stop worry about it and enjoy the darn thing.
     
  13. simonsi macrumors 601

    simonsi

    Joined:
    Jan 3, 2014
    Location:
    Auckland
    #13
    ...and the proximity of Red Matter
     
  14. GP20, Feb 25, 2014
    Last edited: Feb 25, 2014

    GP20 thread starter macrumors member

    Joined:
    Oct 3, 2012
    #14
    Well, another week has passed by, the battery is down to 8355 mAh. It's been gradually decreasing everyday. So in 9 days, the battery dropped 900 mAh.

    Also, when it's fully charged and I unplug the power chord, I open a couple of Safari browsers for a few minutes (no flash), and the estimated remaining time shows less than 6 hours. This was tested after a fresh OS install, and resetting SMC & PRAM many times.

    I talked to Apple, and they're letting me return the computer if I want to. I don't mind returning it anymore, and it really makes me wonder what was going on. Has anyone experienced anything like that with the rMBP battery?
     
  15. joaomigsousa macrumors newbie

    Joined:
    Jun 18, 2014
    #15
    Hello.
    I have a new RMBP 15" 2.3 i7 and i have the same problem with my battery:
    - 3 cycles 9334 mAh
    - 10 cycles 8940 mAh
    - 12 cycles 8670 mAh

    I think its the new strategy of Tim Cook for RMBP buyers having to replace battery after 50/100 battery cycles :~\
     
  16. g.t. rags macrumors 6502

    Joined:
    Nov 25, 2010
    Location:
    Long Island
    #16
    That's ridiculous. Pretty sure that if a battery shows less then 80% degradation withing 350-400 cycles apple will replace the battery for free
     

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