TJakub

Q: MacBook Air battery capacity problem

Hi!

 

 

I have recently discovered that my MacBook Air battery performance is significantly worse than it used to be. I know that batteries are not permanent, but I am using my MBA since November 2015, so it is not an old equipment yet. Its battery cycle count is 239 and as far as I know the battery should keep a good form for at least 1000 cycles. Current maximum charge capacity for the battery is 4680mAh, which is around 10% lower than the design capacity, which should be 5100mAh. Ten percent for a computer that should be usable for about 8-9 hours straight means that I have lost almost an hour of usability during the workday. I am worried how will it look in a year or so. And I am not even mentioning the situation after reaching the 1000 cycles. So is my battery defective or damaged in some way? Should I contact technical support? I still have the warranty which is valid till mid November. I did not use it very intensive and never stored, charged or used it in a high or very low temperature.

 

 

tl;dr

After 10 months of usage and 239 battery cycles my MBA lost 10% of its power capacity. What can I do about it, should Apple warranty cover it?

MACBOOK AIR (11-INCH, EARLY 2015), OS X El Capitan (10.11.6)

Posted on Sep 4, 2016 7:19 AM

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Q: MacBook Air battery capacity problem

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  • by John Galt,

    John Galt John Galt Sep 4, 2016 10:21 AM in response to TJakub
    Level 8 (48,515 points)
    Mac OS X
    Sep 4, 2016 10:21 AM in response to TJakub

    Please read About Mac notebook batteries - Apple Support and http://www.apple.com/batteries/maximizing-performance/.

     

    Over a long period of time, a battery's maximum charge capacity will decrease. Over a shorter period of time, it can decrease or increase... but the long term trend is down.


    That rate of decrease is not linear at all. In other words if you are concerned that your battery will lose another 10% in another year or another 239 cycles, it won't. It could stay at 90% of design capacity for a long time, and probably will. It could decrease a few percent. It might even increase a couple percent. You're not doing anything wrong, and it's not likely you can do anything to influence that either way... as long as you follow Apple's recommendations above.

     

    So is my battery defective or damaged in some way?

     

    There is no indication of that.

     

    should Apple warranty cover it?

     

    Please read https://www.apple.com/batteries/service-and-recycling/. You can certainly contact them, but your battery is operating well within its design specifications.

  • by TJakub,

    TJakub TJakub Sep 4, 2016 10:26 AM in response to John Galt
    Level 1 (8 points)
    Notebooks
    Sep 4, 2016 10:26 AM in response to John Galt

    It says:

    Your battery is designed to retain up to 80% of its original capacity at 1000 complete charge cycles.

     

    My computer is at 239 cycles and it has just 90% of capacity. So it seems to be unlikely that it will lose only 10% more during next 760 cycles, isn't it?

  • by John Galt,

    John Galt John Galt Sep 4, 2016 11:00 AM in response to TJakub
    Level 8 (48,515 points)
    Mac OS X
    Sep 4, 2016 11:00 AM in response to TJakub

    As an electrical engineer I don't know how to explain the phenomenon any more clearly than I already did, without resorting to colorful graphs and charts. Go ahead and contact AppleCare. Perhaps they could explain it better than I can.