kernel_task cpu maxed on battery only

Discussion in 'Mac Basics and Help' started by dave197, May 6, 2011.

  1. dave197, May 6, 2011
    Last edited: May 8, 2011

    dave197 macrumors newbie

    Joined:
    Jan 3, 2010
    Location:
    Stafford, UK
    #1
    My mbp runs fine on mains power but on battery the CPU jumps to nearly 100% and becomes extremely slow

    kernel_task runs at around 15-170 % cpu

    I have tried it in safe boot and it strangely runs fine on battery

    Any ideas
     
  2. simsaladimbamba

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    Location:
    located
    #2
  3. dave197 thread starter macrumors newbie

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    Jan 3, 2010
    Location:
    Stafford, UK
  4. dave197 thread starter macrumors newbie

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    #4
    What does kernel task process do ? , I have looked in console , lots of messages but don't know what to look for
     
  5. simsaladimbamba

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    located
    #5
  6. dave197 thread starter macrumors newbie

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    Jan 3, 2010
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    #6
    mmm, does anyone else know what it can be?

    it works fine on battery in boot camp too

    i dont really use it on the battery but its annoying that it has this problem

    are there any proper hardcore tech heads that i can contact?
     
  7. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #7
    Have you tried resetting the SMC? (Instructions in the following link under CHARGING.) This should answer most, if not all, of your battery questions:
     
  8. dave197 thread starter macrumors newbie

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    Jan 3, 2010
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    #8
    goin round in circles with this....

    done all the above things, new installs, tried lion etc still fubar

    must be hardware problem then?

    thing is i dont get the problem in safe boot, so it must be something thats deactivated ie gpu, kexts etc thats causing the kernel_task to run at 150-190% cpu thus rendering the machine unusable due to it being so slow and jumpy

    it works fine on bttery in windows 7 , just osx
     
  9. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #9
    Uninstall all your widgets.

    Remove everything from:
    • System Preferences > Accounts > your account > Login Items
    • /Library/LaunchDaemons/
    • /Library/LaunchAgents/
    • /Users/username/Library/LaunchAgents/
    Make sure nothing else is launching on reboot. If the problem goes away, add the items back, one at a time, until you find the culprit.

    If it boots OK in Safe Mode, that leads me to believe it's not hardware.
     
  10. dave197 thread starter macrumors newbie

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    Jan 3, 2010
    Location:
    Stafford, UK
    #10

    tried this, still the same

    thanks for your help though
     

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