MacBook Air (2012) Battery Issues

Discussion in 'MacBook Air' started by chrisworld, Jan 29, 2015.

  1. chrisworld macrumors member

    Joined:
    Nov 14, 2006
    #1
    Hey guys. I have a 13 inch 2012 MacBook Air. I have gotten my fair share of mobile use out of the thing, but I'd like to ask other owners of my particular type of machine how their stock battery is holding up as of Jan 2015?

    Just 3 days ago I noticed the "Service Battery" warning under the battery menu and thought that it was a bit odd to see. It didn't surprise me in the least considering the machine's age and charge cycles, but what its been doing after this is actually surprising me.

    I know that Lithium Ion cells don't last forever, but mine just decided to apparently take a nose dive off a cliff in less than one week.

    A week ago, I was able to get several hours per charge. After this problem cropped up I downloaded an app, I believe it is called "Battery Health" to check the vitals, and it did confirm that the battery is of course wearing out slowly. The max mAh was much lower than the projected factory mAh for the battery and it was showing 77% health.

    So I decided to drain the battery by running a full screen youtube video and it killed it in 30 mins. I plugged her in, let her regain a full charge (my suspicion was maybe it needed a good full drain cycle) and low and behold, now were hovering at 64% health and dipping into the 4000's mAh (was 5159 before).

    The calculated remaining time is all over the place too, i've watched it jump between every single number between 20 minutes and 3 hours and not 10 mins off the charger i'm down to 88% from 100%.

    I know I have to replace, but do these batteries usually have such a steep curve when it comes to dying? I thought it would be gradual. Maybe it's gone totally bad with intermittent problems?
     
  2. motrek macrumors 68020

    Joined:
    Sep 14, 2012
    #2
    Calm down. You're kind of going nuts. Your machine didn't need a full drain cycle--that's a thing that was necessary with nickel cadmium batteries from the late 80s. By changing your usage habits you probably confused Apple's software that estimates charge capacity. And it has never been unusual to get wildly varying "time remaining" estimates.

    Just go back to how you were using the battery last week. My guess is that it will resume functioning as expected.
     
  3. cyber16 macrumors 6502

    Joined:
    Jan 12, 2013
    #3
    The battery is likely reporting the "Service Battery" due to an unbalanced weak cell. It happens, run it as long as you are satisfied with the amount of service time it provides.
    How many cycles on the battery? if well under 1k, bring it in just maybe apple will replace it for free if the capacity reflects being well under 80% of original.
     
  4. BeSweeet macrumors 68000

    BeSweeet

    Joined:
    Apr 2, 2009
    Location:
    San Antonio, TX
    #4
    My mid-2012 base 13" MBA has received 2 battery swaps since I bought it in August 2012. The last battery replacement was in Oct. 2014. OS X would indicate "service battery" and my numbers really would be noticeably bad. I have a feeling it'll say the same thing by summer (pretty basic usage as well). Apple said that they may need to look at other hardware if it happens again. So if your battery is just now saying "service battery," then I envy you :).
     
  5. chrisworld thread starter macrumors member

    Joined:
    Nov 14, 2006
    #5
    Who's going nuts?

    It has 224 cycles as of now.

    Heres a screenshot from the other day:
    http://gyazo.com/cd35a3ad74dd23e582135b17893d3590

    And one from just now demonstrating how the data is all over the place:
    http://gyazo.com/29b7d5feaa7594dcea0ac848e8bc73d6
    http://gyazo.com/2c8d27331c7c702a3525a3177b4442da
    http://gyazo.com/edd4f37b2573b3b406795fcf9a625429 (back to 74% now? ... lol make up your mind. This is actually getting entertaining to watch.
     
  6. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #6
    It is perfectly normal if your battery health (maximum capacity) 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.
    You never need to fully drain your battery and doing so is not good for it.
    The time remaining is a constantly-changing estimate, based on the minute-to-minute workload and power demands on your system. It is not accurate and is expected to change frequently as your system runs.

    Run on battery whenever you need to and plug it in whenever you can. You can plug or unplug any time you need to, regardless of the charged percentage, and you never need to completely drain your battery.
    The link below should answer most, if not all, of your battery/charging questions, including tips for maximizing battery performance. If you haven’t already done so, I highly recommend you take the time to read it.
    Not necessarily and not as likely as the fact that the "Service Battery" indicator appears when the battery health drops below 80%.
    Apple will only replace the battery free if it's covered by warranty or AppleCare.
     
  7. BeSweeet macrumors 68000

    BeSweeet

    Joined:
    Apr 2, 2009
    Location:
    San Antonio, TX
    #7
    Or if you pay for it, like I had to do twice.
     
  8. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #8
    Then that wouldn't be free.
     
  9. chrisworld thread starter macrumors member

    Joined:
    Nov 14, 2006
    #9
    I didn't know the battery overall health would fluctuate that much. I assumed it was similar reading to an HDD SMART status.

    This is pretty much the first laptop I've owned, and I never had problems with the batteries in my past and present iOS devices. Interestingly, my 2009 iPod touch 3 still holds and provides the same amount of use it did 6 years ago, and if I had to guess, it's got several thousand charge cycles under it's belt, totally different battery vs. MacBook though.
     
  10. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #10
    Not similar to SMART status at all.
    Are you having problems with your battery, or are you just concerned about the readings? As long as the battery holds sufficient charge to meet your needs and isn't displaying any other symptoms like swelling, it's best to just relax and enjoy your Mac, and don't pay close attention to your battery readings.
     
  11. motrek macrumors 68020

    Joined:
    Sep 14, 2012
    #11
    Batteries are not like cups that you can fill up with water until you reach a line on the side.

    They are impossibly complex geometrical structures of different chemicals with electrons moving around between them in unpredictable ways.

    Thus, you can't simply measure the charge capacity of a battery and call it a day. The capacity has to be estimated based on things like how the output voltage changes as certain amounts of current are applied to it. It's certainly not an exact science.

    By suddenly draining the battery down to 0% all of a sudden, I suspect you confused the methods used for estimating charge capacity.

    As I said, go back to using your battery as you were before, stop worrying about it, and see if it continues to perform the same.

    If it doesn't last as long on battery power then you have cause for concern. But please notice that I'm talking about how long the laptop actually lasts, nothing to do with battery percentages or "time remaining" estimates since that's all they are--estimates.
     

Share This Page