kernel_task cpu maxed on battery only

[dave197]

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

 

[simsaladimbamba]

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Have a look at Activity Monitor (Applications / Utilities /) and select All Processes and sort by CPU to see what the culprit may be.

image below uses sorting by CPU as an example

Further reading:

Mac OS X: Reading system memory usage in Activity Monitor
Making The Most of Activity Monitor​

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[dave197]

It's kernel task , running about 160 % lol

 

[dave197]

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

 

[simsaladimbamba]

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

What is kernel_task? Why is it running?
via "kernel task mac"

 

[dave197]

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?

 

[GGJstudios]

mmm, does anyone else know what it can be?

Have you tried resetting the SMC? (Instructions in the following link under CHARGING.) This should answer most, if not all, of your battery questions:

Apple Notebook Battery FAQ​

 

[dave197]

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

 

[GGJstudios]

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.

 

[dave197]

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.

tried this, still the same

thanks for your help though