Lion problem, computer now shuts off at 25% battery power (but only sometimes)?

Discussion in 'Mac OS X Lion (10.7)' started by iFanboy, Aug 8, 2011.

  1. iFanboy Guest

    #1
    This is weird.

    About half the time i'm running on battery my macbook pro will just "turn off" when the power level gets to 25%

    The rest of the time it will use the power right down to the single digit percentages as normal.

    Anyone else getting this particular intermittent battery problem?
     
  2. iFanboy thread starter Guest

    #2
    Possible Solution - resetting the SMC

    1. Restart your Mac
    2. Hold down the shift, ctrl, and option (cloverleaf/cmd) keys together with the power button
    3. Hold for 10 seconds.
    4. Turn on your Mac

    I haven't had chance to test this yet on a full battery deplete, but i'll report back if issues remain!
     
  3. iLog.Genius macrumors 601

    iLog.Genius

    Joined:
    Feb 24, 2009
    Location:
    Toronto, Ontario
    #3
    If it's happening to you a lot, check your battery. Premature shut downs could indicate that the computer is not reading the battery correctly. This happens to me sometimes but I know it's the battery as it has been needed to be replaced for almost half a year..
     
  4. rorschach macrumors 68020

    rorschach

    Joined:
    Jul 27, 2003
    #4
    Either you need to calibrate your battery or the battery is almost depleted.

    http://www.apple.com/batteries/notebooks.html
    http://support.apple.com/kb/ht1490

     
  5. iFanboy thread starter Guest

    #5
    Ok, so resetting the SMC didn't help.

    I just ran my battery down and when it got to 19% the computer just turned itself off and wouldn't turn itself back on.

    The weird thing is that my battery was perfect under Snow Leopard, and this literally started happening as soon as I installed Lion.

    Could this be a Lion issue or do I need to buy a new battery? :(
     
  6. rorschach macrumors 68020

    rorschach

    Joined:
    Jul 27, 2003
    #6
    In System Information, how many cycles does it say your battery has completed? (Hold option while in the Apple menu, open System Information, and look in" Power" for "Cycle Count".)
     
  7. iFanboy thread starter Guest

    #7
    182.

    My battery was great before Lion. Now it just won't use the last 25%. It will just abruptly shut off the computer instead :(
     
  8. nebo1ss macrumors 68030

    Joined:
    Jun 2, 2010
    #8
    You need to calibrate your battery see post number four.
     
  9. iFanboy thread starter Guest

    #9
    Done. No change in behaviour unfortunately :(
     
  10. iLog.Genius macrumors 601

    iLog.Genius

    Joined:
    Feb 24, 2009
    Location:
    Toronto, Ontario
    #10
    Then your battery is in need of replacing.
     

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