marchetti6AB

Q: Time Machine Back Up may have flattened MBA Battery

I fully charged my mid 2011 11 inch MBA's battery after backing up. I left the MBA's back up portable HDD plugged in overnight. Flat battery next day! Question: with Time Machine switched on enabling its default operation, is it able to switch the MBA on and do hourly back ups to the point of a flat battery? Upon plugging in the charger and booting the MBA, there was a message saying the back up HDD had not been properly dismounted.  Then again I may have inadvertently left the MBA on/asleep. Or is there some other explanation?

iPhone 3GS, iOS 6.1.6

Posted on Sep 5, 2014 4:10 AM

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Q: Time Machine Back Up may have flattened MBA Battery

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  • by Loner T,Helpful

    Loner T Loner T Sep 5, 2014 9:39 AM in response to marchetti6AB
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    Safari
    Sep 5, 2014 9:39 AM in response to marchetti6AB

    Can you check System Preferences -> Energy Saver settings?

     

    Also, please see OS X: About Power Nap

     

    There is a reference to an SMC update for your specific version in that article. You may want to check if you are running the SMC firmware that enables Power Nap? The specific SMC Update came out in July 2012 - MacBook Air SMC Update v1.6 .

  • by marchetti6AB,

    marchetti6AB marchetti6AB Sep 5, 2014 12:36 PM in response to Loner T
    Level 1 (8 points)
    Notebooks
    Sep 5, 2014 12:36 PM in response to Loner T

    Many thanks. Checked Energy Saver settings. Power Nap on when power adapter used. SMC version 1.74f4. I now do not know what I did or did not do that flattened the battery. My recent habit of daily Time Machine back ups is involved, though. I will be extra vigilant in future. I do not want more battery discharges to zero...

     

    Thanks Loner T!

     

    Ken

  • by Loner T,

    Loner T Loner T Sep 5, 2014 12:55 PM in response to marchetti6AB
    Level 7 (24,404 points)
    Safari
    Sep 5, 2014 12:55 PM in response to marchetti6AB

    Can you also check "Put hard disks to sleep when possible" in Energy Saver?

     

    How old is the battery? What Mac/model/year do you have? You can check in About This Mac -> More Info -> System Report -> Power for battery details.

  • by marchetti6AB,

    marchetti6AB marchetti6AB Sep 5, 2014 5:53 PM in response to Loner T
    Level 1 (8 points)
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    Sep 5, 2014 5:53 PM in response to Loner T

    Apologies for the delay in replying. In response - "Put HDDs to sleep when possible" enabled; battery age could not be determined, but in System Info battery condition normal, charges up to Full Charge Capacity,160 cycles so far; Mac Book Air 11 inch MBA4.1, purchased April 2012.

  • by Loner T,Solvedanswer

    Loner T Loner T Sep 5, 2014 7:10 PM in response to marchetti6AB
    Level 7 (24,404 points)
    Safari
    Sep 5, 2014 7:10 PM in response to marchetti6AB

    The tech specs are MacBook Air (13-inch, Mid 2011) - Technical Specifications which has a non-user replaceable battery and 160 cycles is good. It should last roughly about 3+ years, but condition being normal, may last longer.

     

    Typically MBA should have woken up about 8-10 times on battery in an overnight window, which should not have drained the battery. It should sleep properly. The error about disconnection of the disk can be verified in Applications -> Utilities -> Console logs for the exact time of the disk disconnect, which should give you an estimate of how long the MBA was without the drive connected. Repeated disconnects should also be checked for.

  • by marchetti6AB,

    marchetti6AB marchetti6AB Sep 5, 2014 8:31 PM in response to Loner T
    Level 1 (8 points)
    Notebooks
    Sep 5, 2014 8:31 PM in response to Loner T

    Thanks will check further.