Normal battery health for 2012 MacBook Air?

Discussion in 'MacBook Air' started by ccard3dev, Oct 30, 2014.

  1. ccard3dev macrumors regular

    ccard3dev

    Joined:
    Nov 6, 2013
    Location:
    Michigan, US
    #1
    I am only getting 88% of the maximum battery capacity in my 2012 Macbook Air after 104 cycles. I checked a week ago and it was at 94%. Is this normal with good charge/recharge habits? If not, do you think Apple would replace the battery for free (out of warranty)?

    Thanks!
     

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  2. motrek macrumors 68020

    Joined:
    Sep 14, 2012
    #2
    Apple claims 80% charge capacity after 1000 charge cycles.

    I understand that the downward trajectory is worrying but since you still have basically 90% charge capacity left on a laptop that's 2 years old, I wouldn't worry at all.

    The reason it probably dropped quickly from 94 to 88 is because I assume some guesstimation goes into measuring charge capacity so I would expect some fluctuation like this.
     
  3. cyber16 macrumors 6502

    Joined:
    Jan 12, 2013
    #3
    Looks about right, here is my mid 2012 11"
     

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  4. ccard3dev thread starter macrumors regular

    ccard3dev

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    Nov 6, 2013
    Location:
    Michigan, US
    #4
    Thanks for both of your replies!

    I guess I am just being too cautious (I like keeping my devices in perfect shape, and the smallest things bug me)!
     
  5. Isamilis macrumors 6502

    Joined:
    Apr 3, 2012
    #5
    Mine is also 2012, 84% after 310-ish cycles. Previously it was about 74%, and getting better after using FruitJuice (I have no relation at all with dev).
     
  6. motrek macrumors 68020

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    Sep 14, 2012
    #6
    I don't know anything about FruitJuice but I would be very reluctant to mess with Apple's standard software for charging batteries.

    The fastest way to ruin a lithium ion battery is to overcharge it, so if the computer is trying to charge a battery more than it can actually be charged because it has an incorrect measurement of maximum charge capacity, you might find yourself with a dead battery very quickly.
     
  7. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #7
    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.
    FruitJuice doesn't appear to do anything to Apple's standard charging software. It simply reminds the user about battery status and went to unplug and run on battery.
    You cannot overcharge a Mac battery. It automatically stops charging once the battery is full and cannot overcharge. See the CHARGING section of the Battery FAQ for details.
     
  8. motrek macrumors 68020

    Joined:
    Sep 14, 2012
    #8
    This is my point though, how does it know when the battery is full? Because it keeps track of the maximum charge capacity via analyzing charge rates.

    If you do anything to change what it thinks is the maximum charge capacity you could easily ruin the battery.

    If FruitJuice doesn't change any of Apple's information about the battery then I'm sure it's fine. Sorry for any false alarm.
     
  9. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #9
    Apple batteries have chips in them that communicate with the logic board in Apple notebooks, enabling your Mac to determine the charge level of the battery. It has nothing to do with 3rd party software and cannot be changed by such software.
     
  10. Isamilis macrumors 6502

    Joined:
    Apr 3, 2012
    #10
    Sorry I don't have any benefit from FruitJuice. I only share my experience. Yes GGJstudio is right, it only scheduler remind when you are free to unplug. How does it know? Based on statistic of your usage. It took around 2 days keep running to get quite accurate result. No magic at all. Just google to find the details. I was also pessimist in the beginning but my battery is getting better now. Again, I have no affiliation at all. Your experience may be vary.
     
  11. qpid360 macrumors 6502

    qpid360

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    Pasadena, CA
  12. kage207 macrumors 6502a

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    Jul 23, 2008
    #12
    Batteries will fluctuate. As long as you are getting good battery life, I wouldn't worry about it at ~90%. Keep in mind, if you do have Apple Care (3 years) then they will replace it once it falls below 80%.
     
  13. GGJstudios macrumors Westmere

    GGJstudios

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    May 16, 2008
    #13
    Only if it falls below 80% before 1000 cycles.
     
  14. filmbuff macrumors 6502a

    filmbuff

    Joined:
    Jan 5, 2011
    #14
    My 2012 has about 275 cycles on the battery and it's at 68%. It says "service battery". I mostly use it at my desk plugged into a monitor so I don't care, but it's nowhere near the 1000 cycle guarantee.
     
  15. kage207 macrumors 6502a

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    Jul 23, 2008
    #15
    Well, I'd be very surprised if someone passed 1000 cycles in 3 years.
     
  16. GGJstudios macrumors Westmere

    GGJstudios

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    May 16, 2008
    #16
    Many have. It's not uncommon. The point is that for Apple to replace the battery free, it must be in some other way defective or all of the following conditions must be met:
    1. It must be below 80% health
    2. It must have fewer than 1000 cycles
    3. It must be covered by AppleCare
     
  17. motrek macrumors 68020

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    Sep 14, 2012
    #17
    Well, these newer MBAs have ~9+ hours battery life so they'd have to be using their computers on battery power for over 9 hours per day every day for 3 solid years to rack up 1000 cycles... I don't know anybody who uses a computer that much, or at least who does so without access to a power outlet...
     
  18. GGJstudios macrumors Westmere

    GGJstudios

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    May 16, 2008
    #18
    There have been posts in this forum by those who have. As I said, it's not uncommon, although most users don't consume cycles at that rate.
     
  19. kage207 macrumors 6502a

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    Jul 23, 2008
    #19
    The MBAs from 2012 get about 7 hours. At least I do, even when I do web development. If I do iOS I get about 4-5 hours.
     
  20. motrek macrumors 68020

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    Sep 14, 2012
    #20
    Good point. But 7+ hours every single day for 3 years is still a lot of battery use. I'm not saying it's impossible but I think describing it as "common" is an exaggeration.
     
  21. truettray macrumors 6502

    truettray

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    Sep 7, 2012
    Location:
    USA
    #21
    Man I can't even keep the battery percentage on my iPhone displayed without stressing over it... I can't imagine how much it would stress me out to keep a close eye on my battery health..
     
  22. kage207 macrumors 6502a

    Joined:
    Jul 23, 2008
    #22
    I know. I'm a power user and I'm only at like 360 cycles for my 2012 MBA. It's the other guy who was saying that there are still some people who do.

    While I totally understand their outliers I think they shouldn't be concerned.
     
  23. qpid360 macrumors 6502

    qpid360

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    #23
    Funny. I left for a week with my 2012 Air shut off. I just came back today and as soon as I powered on, it now states 'service battery'.
     

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