Battery capacity deterioration?

Discussion in 'MacBook Air' started by zRedbullz, Nov 28, 2010.

  1. macrumors regular

    zRedbullz

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    #1
    Hello,

    According to Coconut battery, my MBA is 9 weeks old and the capacity has dropped to 96%.

    Is it normal?

    I didn't quite expect it to drop 4% in just a matter of weeks.... I did one battery calibration when I bought it since new.

    Thank you
     
  2. macrumors demi-god

    SandboxGeneral

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    #2
  3. macrumors 6502a

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    #3
    Mine came wit a 0 cycle battery at 98% health which did not make me particularly happy but after a few cycles it registered 99%.

    One thing for sure is that every battery will deteriorate with use, cycles, and time. It's just a matter of how fast.

    My uMB is at 100% still after over two years of use but I've had others deteriorate much faster. Usually I get several years before health reduced battery life to the point I'd consider replacing the battery.

    Not sure of the cost of a new MBA battery will be but Apple would replace the old ones for about $100. And if the age of the battery or number of cycles on it was within apples spec when the battery reported It needed replacing, the replacement is a free warranty item.
     
  4. macrumors 6502

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    #4
    I just decided to try out coconut battery on my 4 month old MBP. It shows I have only 88% of capacity (5125 mAh of 5770 mAh). I have only ran 17 battery load cycles. Does this seem normal? I have tried googling, searching forums, and many seem to have it be 95% for the first 30+ cycles so this seemed odd.
     
  5. macrumors demi-god

    GGJstudios

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    #5
    Have you properly calibrated your battery? See the link in post #2 for the calibration procedure. How often do you run your MBP on battery power, and how much on AC power?
     
  6. macrumors 6502

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    #6
    I almost always run on battery. I guess I thought it was bad to keep it plugged in but from what I have read, I was wrong. I have not calibrated but am in the process of charging it to max value as we speak.
     
  7. macrumors demi-god

    GGJstudios

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    #7
    If you read the information in that link, you'll find how best to use your battery to maximize its life.
     
  8. macrumors regular

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    #8
    My 13" 2009 MBP is at 139 charges, it fluctuates between 95 and 97 most of the time - Never seen it go 94% or lower.
     
  9. macrumors 604

    chrono1081

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    #9
    FYI Apps like Coconut Battery are estimations only. You will see a TON of misinformation (I've seen it on these forums) where people who don't know what they are talking about say things like "Coconut Battery is accurate because it reads the battery straight from the system!!!11!" Yes, it does, and the system only provides an estimate, nothing more.

    Anyway its perfectly normal and you usually will never see 100%.
     
  10. macrumors member

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    #10
    Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_1 like Mac OS X; en-us) AppleWebKit/532.9 (KHTML, like Gecko) Version/4.0.5 Mobile/8B117 Safari/6531.22.7)

    Yeahi have gone through 9 cycles and am at 96%. Worried me a bit, and will probably keep the power in more for normal use.
     
  11. macrumors 68000

    BeyondtheTech

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    #11
    I've gone through five different MacBooks and Airs over the past three years, and I've always seen my batteries stop anywhere from 96% to 100% each and had as many as 400 cycles, so I wouldn't be worried. I think it's just a calibration issue.
     
  12. macrumors demi-god

    GGJstudios

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    #12
    Read the AC Power section of the Apple Notebook Battery FAQ for recommended battery/AC usage.
     
  13. macrumors 68000

    gwsat

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    #13
    That's right. Apple's battery FAQ has this to say on the matter:

     
  14. macrumors 6502

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    #14
    I guess I was premature on my post. I had always run it off of the battery instead of using the plug when I was nearby. In the last two weeks I have since changed these behaviors and Coconut Battery now shows 93% capacity. I suppose you learn as you live.
     

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