Battery capacity decreasing with every charge cycle

Discussion in 'MacBook Air' started by 007bond, Sep 4, 2012.

  1. macrumors 6502a

    007bond

    Joined:
    Dec 12, 2008
    Location:
    DFW, Texas
    #1
    I'm kind of at a loss, honestly. Is this normal? At this rate, 100 charge cycles will take me to 0% battery health.
     

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  2. macrumors member

    Joined:
    Jul 1, 2010
    #2
    My MBP battery has quite a large fluctuation anywhere from 95% down to 85% and there seems to be no rhyme or reason as to when it goes up or down. I always use it the same with mostly connected to power, yet some weeks it will hover around 85% and others will be 95%

    Doesnt ever seem to dip below that though. Also my battery has 236 cycles.
     
  3. macrumors 68030

    Spink10

    Joined:
    Nov 3, 2011
    #3
    Battery can fluctuate - however if it continues this trend over a few more days then you may have something weird.
     
  4. macrumors 68020

    Mlrollin91

    Joined:
    Nov 20, 2008
    Location:
    Ventura
    #4
    Yes it is normal. It is normal for the health of the battery to increase and decrease with every charge cycle.

    My GF's MBPs battery health was down to 69% last week. After cycling the battery a few cycles its back to 89%.

    Unless the health stays below 80% before a 1000 charges it is normal.
     
  5. macrumors 65816

    Joined:
    Jan 5, 2011
    #5
    The capacity does not start at 100% and just decrease to 0 - it can fluctuate up and down. You don't have anything to worry about at this point.
     
  6. thread starter macrumors 6502a

    007bond

    Joined:
    Dec 12, 2008
    Location:
    DFW, Texas
    #6
    Thanks for the info, everyone. Does everyone think this battery capacity is normal for so few cycles?
     
  7. macrumors 6502a

    monkeybagel

    Joined:
    Jul 24, 2011
    Location:
    United States
    #7
    I would try the battery recalibration method. I did this on mine - a new 15" MacBook Pro (2012) and it increased to full charge capacity to about 71xx from 69xx. Still reads 71xx.
     
  8. thread starter macrumors 6502a

    007bond

    Joined:
    Dec 12, 2008
    Location:
    DFW, Texas
    #8
    Do you mean let the battery completely discharge and wait till it charges 100%?
     
  9. macrumors regular

    Joined:
    May 5, 2011
    Location:
    Costa Rica
    #9
    It happens to my Macbook Pro too since I installed Mountain Lion. It may be a bug related to the lower battery life reported.
     
  10. macrumors 68040

    Cynicalone

    Joined:
    Jul 9, 2008
    Location:
    Okie land
    #10
    It is normal for a new battery to fluctuate. My 2011 model settled between 88 and 92% and has been there for over a year.

    Screen Shot 2012-09-04 at 11.02.50 AM.png

    There is no need to calibrate the batteries in the current MacBook models. Just use it and don't worry about it.
     
  11. macrumors 6502a

    Joined:
    Jan 1, 2012
    #11
    mines dropped to 90% from 95 when i bought it. very annoying every time i check its dropped again
     
  12. macrumors 65816

    Joined:
    Jan 5, 2011
    #12
    Why do you check the battery like this? Seriously - it's not worth the time and effort. There will be an occasional bad battery out there that doesn't last as long as it should, but all you need to do is head into an Apple store and have them check the battery just before your Warranty expires (1 year or 3 years with AppleCare) - if there is a problem, they will replace it. In the meantime, you do not need to check your battery level or worry about it.
     
  13. macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #13
    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/charging questions:
    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. Also, calibration has zero effect on your battery's health. Read the Battery FAQ for details.
     
  14. macrumors 6502a

    monkeybagel

    Joined:
    Jul 24, 2011
    Location:
    United States
    #14
    In a nutshell, but you let it run all the way down until it hibernates on its own. Then you allow it to sit for 3-4 hours, then connect it and allow it to charge completely. Before you start the process, allow it to charge to 100% and allow it to remain on the charger for 4-5 hours after it reaches 100%.

    You will read many links and posts saying that it is not needed and is unnecessary, however I can speak from experience that it will make the battery meter more accurate and also show your full charge capacity more accurate.

    Read here for more information.

    http://support.apple.com/kb/HT1490
     
  15. macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #15
    That is not the proper procedure for calibration. Before you give bogus advice, you should get the facts.
    From the link you posted:
     
  16. monkeybagel, Sep 4, 2012
    Last edited by a moderator: Sep 5, 2012

    macrumors 6502a

    monkeybagel

    Joined:
    Jul 24, 2011
    Location:
    United States
    #16
    Wow - great way to make friends on the forum!

    I know from personal experience that makes a difference and I know what the article says. It says in the article that it is not needed on models with non-removable batteries, and it is not required, but it does make a difference in the battery meter readings.

    Please, believe what you wish. I have done this and I know what my experience was and am sharing it. I have also done this on a new ThinkPad and got the same results.

    ----

    Here is a link describing how this procedure has helped newer MacBooks as well.

    The machine has charging circuitry that prevents the battery from discharging to the point it will damage the battery, so from everything I have read and from my experience, it is safe.

    http://macheist.com/forums/viewtopic.php?id=16876
     
  17. macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #17
    I'm more interested in making sure people who read this forum aren't misled by misinformation than I am in making friends. People come here for help and accurate information. The procedure you described is not the proper procedure for calibrating a battery. In addition, calibration has no effect on battery health. It only makes the readings somewhat more accurate. It is absolutely unnecessary on newer Mac notebooks with built-in batteries, and doing so is putting cycles on the battery needlessly, with no meaningful benefit. I'll believe Apple, who makes the batteries, more than I'll believe any individual user.
     
  18. macrumors 6502a

    monkeybagel

    Joined:
    Jul 24, 2011
    Location:
    United States
    #18
    That's all well and good. I have read many of your posts and you do generally give accurate information. But indirectly calling someone a liar that has first hand experience is not very professional.

    As I am sure you know, the battery gauge is an estimation of how much the battery's circuity thinks the remaining runtime is. It is not a true gauge of battery health. However, this is all we have to go on when we check the battery's health, so improving the accuracy of this reading is beneficial, and this procedure, although labeled for older notebooks, is effective at restoring the accuracy of this meter.

    I do not believe one charging cycle for a battery that is supposed to be good for over one thousand will shorten the life of the battery.

    The notebook can be used during this time. The only inconvenience is allowing it to sit in hibernation for three or four hours.

    I am only sharing my own experience with my 2012 MacBook Pro and ThinkPad. Both yielded the same result, increasing the full charge capacity reading. I will try to find time to do it on my wife's 2011 MacBook Pro and see what it does.
     
  19. macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #19
    I didn't call anyone a liar. I said that the procedure you claimed was calibration is, in fact, not the proper calibration procedure.
    Again, you're making up your own procedure. If you're going to calibrate a battery, the procedure you described will not do it. Read the CALIBRATION section of the Battery FAQ for the correct procedure.
     
  20. macrumors 6502a

    monkeybagel

    Joined:
    Jul 24, 2011
    Location:
    United States
    #20
    Sigh...

    I hardly made this up.

    Here is the procedure from the Apple document...

    Emphasis is mine.

    The battery calibration for the PowerBook G4 (15-inch Double-Layer SD) and any model of MacBook or MacBook Pro has been updated because of a new battery released with this computer. With these computers, follow these steps to calibrate your battery:

    Plug in the power adapter and fully charge your PowerBook's battery until the light ring or LED on the power adapter plug changes to green and the onscreen meter in the menu bar indicates that the battery is fully charged.
    Allow the battery to rest in the fully charged state for at least two hours. You may use your computer during this time as long as the adapter is plugged in.
    Disconnect the power adapter while the computer still on and start running the computer off battery power. You may use your computer during this time. When your battery gets low, the low battery warning dialog appears on the screen.
    At this point, save your work. Continue to use your computer; when the battery gets very low, the computer will automatically go to sleep.
    Turn off the computer or allow it to sleep for five hours or more.


    Connect the power adapter and leave it connected until the battery is fully charged again.

    With all due respect, I am not going to respond any more to you regarding this matter. If the OP has any questions, I will be glad to help any way I can.
     
  21. macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #21
    I'm intimately familiar with the proper calibration method and, as I said before, the procedure you were suggesting was not accurate. No where in the Apple procedure that you quoted will you find the following:
    Nor will you find any mention of this:
    When giving instructions, it's far more beneficial to readers if you simply quote or link to the Apple document, rather than paraphrasing or estimating or guessing.
     
  22. macrumors 68030

    Joined:
    Nov 7, 2004
    #22
    Battery life is a lottery
     

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  23. macrumors 6502a

    monkeybagel

    Joined:
    Jul 24, 2011
    Location:
    United States
    #23
    Draining the battery and charging as stated above increased the Full Charge Capacity from 5555mAh to 5643mAh.

    This should increase the accuracy of your battery meter and give you slightly more runtime before the machine forces hibernation.

    Worth a shot.
     

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  24. macrumors 68040

    Joined:
    Feb 6, 2009
    #24
    Apple uses the term "go to sleep", but really when your Mac automatically sleeps from low battery it goes into a state that could correctly be called 'hibernation', where the contents of RAM are written to disk to prevent data loss.
     
  25. macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #25
    Models like the MBA and MBPr have a hibernation mode called "standby mode" that can last up to 30 days on a charge. That mode is not available on other MBPs. This is one reason why trying to calibrate a MacBook Air won't work correctly, since 5+ hours won't drain a MBA battery as much as it would drain the removable batteries that required calibration. Those calibration instructions were written before standby or hibernation mode even existed.
     

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