*Post your 2012 MBA's battery Full Charge Capacity (mAh)*

Discussion in 'MacBook Air' started by Jobsian, Jun 19, 2012.

  1. Jobsian, Jun 19, 2012
    Last edited: Jun 19, 2012

    Jobsian macrumors 6502a

    Jobsian

    Joined:
    Jul 30, 2009
    #1
    I'm wondering about the variability here as it seems quite high from what I'm reading. From this site it seems the design capacity of these batteries is

    4680 mAh for the 11" models
    and
    6700 mAh for the 13" models


    Post which 2012 MBA you have and its capacity from the System Report (click About This Mac in the top left of the screen then 'more info'). Mine:

    11" - Full Charge Capacity (mAh): 4592


    _
     
  2. RocketRed macrumors 6502a

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  3. AlanShutko macrumors 6502a

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  4. Jobsian thread starter macrumors 6502a

    Jobsian

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    Jul 30, 2009
    #4
    Does anyone know whether or not this is a fixed number early on into the cycles, as we're already seeing some variability?
     
  5. Higgs1 macrumors 6502

    Higgs1

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    Jun 6, 2009
    Location:
    Boston, MA
    #5
    Current: 6462
    Max 6538

    Capacity 6538
    Deisgn Capacity 6700 :confused:
     
  6. saleemyas3 macrumors regular

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    Jun 1, 2012
  7. Intell macrumors P6

    Intell

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    #7
    The full charge capacity will go up and down throughout the machine's life. This is normal. It can range from 85% to 110% and still be normal.
     
  8. Beau10 macrumors 6502a

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    Downtown San Diego
    #8
    My 11" has fluctuated a bit from 4732-4799 (currently 4786 on 3 cycles). Haven't bothered to do a full calibration yet, just got the machine yesterday. Will let it go thru a few more cycles first.
     
  9. dmk1974 macrumors 68000

    dmk1974

    Joined:
    Sep 16, 2008
    #10
    2012 11" base Air
    5 charge cycles
    Full Charge Capacity (mAh): 4516

    That kinds sucks, right?
     
  10. jgc macrumors regular

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    Canada
  11. GGJstudios, Jun 19, 2012
    Last edited: Jun 19, 2012

    GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #12
    The built-in batteries in the newer Mac unibody notebooks come pre-calibrated and do not require regular calibration like the removable batteries.

    This should answer most, if not all, of your battery questions:

    iStat Pro will give you battery information, as well as temperatures, fan speeds, uptime, etc. It's very handy.... and free!
     
  12. JDrive macrumors member

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    Jun 3, 2010
    #13
    From the "About This Mac" window click "More Info...". Then click "System Report..." and "Full Charge Capacity (mAh)" is listed under "Power".

    My 13" currently lists 6566.
     
  13. mitty macrumors regular

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    Melbourne
  14. Beau10, Jun 20, 2012
    Last edited: Jun 20, 2012

    Beau10 macrumors 6502a

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    #15
    While the battery may be now calibrated from the factory (and that's interesting, thank you), that they do not benefit from further calibration is certainly wrong - they must be speaking to a consumerist POV where sure, it isn't quite necessary "do not require". I experienced this in my last MBA and would routinely see my battery change by up to 5% after letting it go for a couple months.

    All lithium ion batteries suffer drift in their readings, and clearly that's what I was getting at - getting an accurate reading of the capacity. That's the point of this thread, no?
     
  15. GGJstudios macrumors Westmere

    GGJstudios

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    May 16, 2008
    #16
    Tell that to Apple. Generic information about lithium ion batteries don't necessarily apply to the specific implementation in Apple's lithium polymer battery technology. I would trust the manufacturer, who is financially responsible to replace defective batteries and who is responsible if the information they provide is flawed. They know more about their own technology than any generic site.

    While calibrating the battery in unibodies won't harm it, it's not necessary.
     
  16. Beau10 macrumors 6502a

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    Apr 6, 2008
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    Downtown San Diego
    #17
    Tell what to Apple? The point of this thread and "replacing defective batteries" are orthogonal to each other.

    Apple may have somehow reduced the tendency to drift, but there's no way they can fix what is inherent in the technology.
     
  17. zMacintoshz macrumors regular

    zMacintoshz

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  18. Jobsian thread starter macrumors 6502a

    Jobsian

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    Jul 30, 2009
    #19
    I'm 4 cycles in and from my opening post when I was getting 4592 mAh, it has gone down to

    Full Charge Capacity (mAh): 4576

    I wonder if this is normal? Will be interesting to see where it goes from here, I'm hoping up!
     
  19. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #20
    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. For further details, read the CHECKING STATUS AND HEALTH section of the following link.

    This should answer most, if not all, of your battery questions:
     
  20. Jobsian thread starter macrumors 6502a

    Jobsian

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    Jul 30, 2009
    #21
    Thanks, will do.

    Health at 97%
     
  21. Jobsian thread starter macrumors 6502a

    Jobsian

    Joined:
    Jul 30, 2009
    #22
    Did a recalibration. Guess what I got?

    11" Full Charge Capacity (mAh): 4600

    Right on the money!
     
  22. Hichisky macrumors member

    Joined:
    Nov 5, 2010
    #23
    On my 11" I am getting:
    Full Charge Capacity (mAh): 4454

    Which I think is the lowest so far. I might try the calibration thing, though supposedly you don't need too.
     
  23. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #24
    You definitely don't need to calibrate. Remember, calibration does not affect or change your battery health in any way. It only makes your readings more accurate.
     
  24. Hichisky macrumors member

    Joined:
    Nov 5, 2010
    #25
    Yeah, I know, I was speaking in terms of getting a more accurate reading. But I figure I won't bother. I feel the battery life is pretty decent anyway. Thanks. :)
     

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