2013 MBA 13" battery life deteriorating?

Discussion in 'MacBook Air' started by zephonic, Jan 16, 2014.

  1. zephonic macrumors 65816

    zephonic

    Joined:
    Feb 7, 2011
    Location:
    greater L.A. area
    #1
    When I first got my MBA in June last year, it could do more than 10 hrs on one charge.

    Over the last week (or maybe two) that has dropped considerably.

    I have not updated the OS to Mavericks, nor downloaded a bunch of new apps. Only app I have running in the background is Box Sync.

    Just now, percentage dropped from 70% to 38% in just over one hour, just browsing on Firefox. Previously, this would not drop as fast.

    What gives?
     
  2. robvas macrumors 68020

    Joined:
    Mar 29, 2009
    Location:
    USA
  3. Weaselboy Moderator

    Weaselboy

    Staff Member

    Joined:
    Jan 23, 2005
    Location:
    California
    #3
    :eek: That is definitely not normal.

    While this is going on start Activity Monitor and look in the CPU tab then sort by % to see if something is chewing up CPU cycles and running down the battery.
     
  4. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #4
    It sounds like you may have an app or process running that is consuming system resources and increasing the power demands on your system. Follow every step of the following instructions precisely. Do not skip any steps.
    1. Launch Activity Monitor
    2. Change "My Processes" at the top to "All Processes"
    3. Click on the "% CPU" column heading once or twice, so the arrow points downward (highest values on top). (If that column isn't visible, right-click on the column headings and check it, NOT "CPU Time")
    4. Click on the System Memory tab at the bottom.
    5. Take a screen shot of the entire Activity Monitor window, then scroll down to see the rest of the list, take another screen shot
    6. Post your screenshots.

    There are many factors that impact your battery life. See the BATTERY LIFE FROM A CHARGE section of the following link for details, including tips on how to maximize your battery life.
    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.
     
  5. zephonic thread starter macrumors 65816

    zephonic

    Joined:
    Feb 7, 2011
    Location:
    greater L.A. area
    #5
    Weirdest ish, now the battery life is back up to 42%!!! :confused:

    Screenshot attached. Nothing out of the ordinary, as far as I can tell...
     

    Attached Files:

  6. Weaselboy Moderator

    Weaselboy

    Staff Member

    Joined:
    Jan 23, 2005
    Location:
    California
    #6
    Agreed... nothing odd there. Maybe leave Activity Monitor open and keep an eye on it when this happens again. It may have been a browser tab you had going in Firefox with a misbehaving web page.
     
  7. iizmoo macrumors 6502

    Joined:
    Jan 8, 2014
    #7
    Are you watching flash movies in FireFox? Flash and games are the only things I've done that can account for that kind if battery drain in mine.

    Is this box Sync new? Last year there was a big bug in dropbox that drained the MBA in around 4 hours. Runaway backgound orocesses kill battery, might try to disable that and see if it make a difference.
     
  8. zephonic thread starter macrumors 65816

    zephonic

    Joined:
    Feb 7, 2011
    Location:
    greater L.A. area
    #8
    Not watching Flash movies, and I have Noscript enabled in FF. But I did allow a few sites with (what looked like heavy flash-based) advertising to run in search for new tires. Still...40% down in an hour? Not likely. And again, this has been happening over the last week (or maybe two).

    Box Sync has been on this computer since day one. No updates that could have altered functionality, AFAIK.
     
  9. Jefe's MacAir macrumors 6502

    Joined:
    Nov 21, 2010
    #9
    Try Click to Flash to at least disable those Flash adds. Couldn't hurt.
     
  10. zzzzzzz macrumors newbie

    Joined:
    Jan 7, 2014
    #10
    FYI there are certain usage habits that will either prolong or deteriorate the capacity of a Lithium battery.

    If possible you should avoid deep cycles and to a lesser extent even full charges. Basically a Lithium battery is happiest sitting around 40-60% charge, dropping below 20% or being constantly topped up above 95% is considered stressful to the battery.

    This is contrary to the older Nickel based chemistry that had some memory effect, and preferred full charge and discharge cycles. Unfortunately the advice relevant to these batteries has lived well past the actual chemistry, as most modern consumer rechargeable batteries are Lithium based.

    Obviously in real life usage you will fully charge the battery, and fully discharge it too when you need to use its full capacity, but many times you don't actually need to do those things - and that will help prolong the battery.

    In short, don't let the battery charge level drop below 20% unless you need to, and don't leave it sitting on the charger for days. If you follow good habits you can watch the battery capacity rise in my experience - I'm currently using a battery from a 2013 MBA, and its capacity is currently 7300mAh (up from its claimed capacity of 7150mAh, and its actual capacity of 6950mAh when I bought it).
     
  11. zephonic thread starter macrumors 65816

    zephonic

    Joined:
    Feb 7, 2011
    Location:
    greater L.A. area
    #11
    Thanks. I was indeed still following old procedures of draining the battery completely and giving it a full recharge.

    However, I do remember Apple recommending to completely discharge the battery at least once a month. Is that out the window, too?
     
  12. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #12
    Yes. 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.

    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. Just make sure you don't run on AC power exclusively, as your battery needs to be used regularly to stay healthy.
    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.
     

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