Model A1286. Released February 2011 / 2.0, 2.2, or 2.3 GHz Quad-core Intel Core i7 Processor

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Kernel_task going crazy, battery level related issue.

First off, I shoud say that I'm fairly new to the MacOS enviroment. I haven't been a Mac guy for the most parts and only joined the club after a guy passed me his old MBP, early 2011. It is running on Sierra 10.12.4 now and I'm having issues with the kernal_task taking up excessive, crippling CPU resources. I notice that this almost always happens when the battery % gets close to 100% and there are a few ways to temporary get it to calm its tits, but it will go crazy again after some time.

The first way to calm it is to have it connected to the charger, and letting it go to sleep and wake it after a minute. This is the less effective solution of the 2 as the calming effect doesn't stay for as long. And as soon as I take it off the charger the kernel goes crazy again. The other method is the do the standard SMC reset and NVRAM reset with the macbook off and charging. This way, the system stays good for longer but is also goes to siht as soon as the battery gets full. It seems the only steady state is when the battery is going up. If its full or going down (not charging), siht happens.

What gives?

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Battery related issues are not that uncommon unfortunately, especially when batteries are third parties replacements that have logic controllers or thermal sensors not up to due standards .Sometimes issues are caused by older batteries near to the end of their life cycle too. You didn't mention what kind of battery is installed, but you can check its condition/life cycles through system informations/power accessed through the apple menu on top left screen. You can also install Coconut Battery which is even more informative to get a better picture.

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I'm using the original battery but it sure has aged and might actually be part of the problem, the other part being the OS software trying to do silly things to slow down the system. Can I just remove the battery and hope the problem will go away? I read somewhere that a macbook will automatically slow down when no battery is installed, which is totally silly. I'm not intending to pony up on a new battery for a old macbook.


Sure you can disconnect battery if you can use it without it for your purposes..only problem will be having to reset time and date every time you turn it on. Statement that a mac will slow down without battery has no ground whatsoever. If you see any weird process taking up lots of cpu other than kernel task after disconnecting battery just reboot and it will disappear.


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