4 Replies Latest reply: Mar 9, 2014 6:48 PM by maxfenton
Pismo Level 1 (115 points)

So, I've asked this question before and never got an answer.


Figures, right?


Anyway, sometimes I'll leave my MacBook Air on without the power adaptor attached, and the battery will drain.


That's all fine and dandy.


The problem is, is that instead of going to sleep LIKE IT SHOULD, it will completely turn off, and everything I had up (web pages, anything and everything) will be GONE when it starts back up.







13-inch MacBook Air, Mac OS X (10.6.6), M-Audio Keystation 61es
  • John Galt Level 8 (44,680 points)

    Pismo, check your system profiler in About this Mac > More Info > Power. I don't know if that is exactly what it is called with Snow Leopard but there ought to be battery diagnostic information buried in there somewhere.


    Copy and paste it here.


    I'm wondering if your battery is on the verge of failing.

  • Pismo Level 1 (115 points)

    Thank you for helping!


    There are two diagnostics - Apple Hardware Test and Power On Self-Test. The POST passed but the AHT failed.


    Apple Hardware Test:


      Last Run:          2/10/11 3:29 AM

      Version:          3A204

      Test Suite:          Extended Test

      Result:          Failed

      Failure Code:          4SNS/1/40000001: ID0R-0.040


    There is battery information though:


    Battery Information:


      Model Information:

      Serial Number:          D86041701W7DCQ8AQ

      Manufacturer:          SMP

      Device Name:          bq20z451

      Pack Lot Code:          0000

      PCB Lot Code:          0000

      Firmware Version:          0301

      Hardware Revision:          0002

      Cell Revision:          0162

      Charge Information:

      Charge Remaining (mAh):          5131

      Fully Charged:          No

      Charging:          Yes

      Full Charge Capacity (mAh):          6168

      Health Information:

      Cycle Count:          299

      Condition:          Normal

      Battery Installed:          Yes

      Amperage (mA):          2362

      Voltage (mV):          8281



  • John Galt Level 8 (44,680 points)

    OK, that AHT code is normal when the power cord is NOT connected: http://support.apple.com/kb/TS3578


    It looks like your battery is just fine also.


    Try this: Reset the System Management Controller. Reasons for doing that are many but include the following (bold emphasis added):



    The computer doesn't respond to the power button when pressed.

    A portable Mac doesn't appear to respond properly when you close or open the lid.

    The computer sleeps or shuts down unexpectedly.


    Intel-based Macs: Resetting the System Management Controller (SMC)


    On the MBA, the procedure is as follows:


    1. Shut down the computer.
    2. Plug in the MagSafe power adapter to a power source, connecting it to the Mac if its not already connected.
    3. On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time.
    4. Release all the keys and the power button at the same time.
    5. Press the power button to turn on the computer. 
      : The LED on the MagSafe power adapter may change states or temporarily turn off when you reset the SMC.

    Post back with your results.

  • maxfenton Level 1 (0 points)

    This could be because (as a preference) the sleep mode has been changed from Safe Sleep to something else.


    cf: http://macs.about.com/od/usingyourmac/qt/Change-How-Your-Mac-Sleeps-Pick-The-Sle ep-Setting-You-Want-Your-Mac-To-Use.htm


    To quote from that article:


    When the Terminal window opens, enter the following at the prompt:

    pmset -g | grep hibernatemode

    You should see one of the following responses:

    hibernatemode 0

    hibernatemode 1

    hibernatemode 3

    Zero means normal sleep and is the default for desktops; 1 means hibernate mode and is the default for older portables;
3 means safe sleep and is the default for portables made after 2005


    I was having the problem you are describing on a Macbook Air. When I ran that command in Terminal, it said I was in `hibernatemode 0`


    To fix it, I entered this command, then enter, then my password.

    sudo pmset -a hibernatemode 3