Rapid Battery Drain While Sleeping

Discussion in 'MacBook Pro' started by mizzoucat, Mar 31, 2011.

  1. mizzoucat, Mar 31, 2011
    Last edited: Mar 31, 2011

    mizzoucat macrumors regular

    Joined:
    Mar 8, 2005
    #1
    I just got my new 13" early 2011 base model yesterday and was using it with an external display while it was plugged in. After leaving it plugged in for a couple of hours after reaching 100%, I unplugged it and started using the notebook in mirrored mode with the display open (since you can't run clamshell mode off of battery power). When I went to bed last night, it had drained down to around 60%. I closed the lid and it went to sleep. I left the external monitor plugged in but I turned the power to the monitor off. When I came home from work today, upon opening the lid, I was shocked the battery had drained down to 20%! Why would it drain 40% while sleeping in less than 18 hours? Does it use extra battery power while sleeping when connected to an external monitor? I did have an external hard drive connected. Does time machine somehow operate while the MacBook is sleeping? I also have bluetooth enabled with a bluetooth mouse connected. coconutBattery is reporting 101% health. Any ideas?
     
  2. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #2
    First: Calibrate your battery to make sure your readings are accurate. (instructions in the FAQ link below)
    Second: Mac OS X: Why your Mac might not sleep or stay in sleep mode
    Third: Your Mac will consume about 1% of battery power for every hour in sleep mode.

    This should answer most, if not all, of your battery questions:
     
  3. mizzoucat thread starter macrumors regular

    Joined:
    Mar 8, 2005
    #3
    Just to confirm, with the lid closed and the computer sleeping in battery mode, it can't wake up under any circumstances, right?
     
  4. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #4
    Yes, it can. Read the link I posted.
     
  5. mizzoucat thread starter macrumors regular

    Joined:
    Mar 8, 2005
    #5
    After reading your link, I'm thinking it was either the external hard drive using a little extra power while being plugged in or the Microsoft bluetooth mouse that was connected.
     

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