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Question: MBP Running slow when its on batteries .. working fine when plugged to the charger ?!

Hi there !
I noticed that my MBP is running very slow when it's on batteries.. but when plugged to charger it works fine..

Is the battery drained already ? I purchased it OCT 2011 but has been using it lightly for almost 5 months ..

P.s : I cleaned it up coz I thought its a space or piled files issues but it didn't work

Thank u in advance 🙂

MacBook Pro, Mac OS X (10.7)

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Feb 20, 2017 1:57 AM in response to Gsianturi In response to Gsianturi

Did you disable "System Integrity Protection (SIP)" yet?

I did just only three steps

- Disable SIP with "terminal" under "recovery system" mode

- Find MacBookpro8_1.plist and delete

- Enable SIP

Here is how to disable and enable SIP


Hope it works with you too


Feb 20, 2017 1:57 AM

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Apr 10, 2017 2:25 PM in response to RoXy1988 In response to RoXy1988

Thanks everybody to all replies. It helps a lot to future people like me. I still have a question. After deleting the plist file, is it ok to the system works without it ? After restarting the mac i checked if the system could created the file, but it wasn't there. It seems my mac is running ok even without it.

Apr 10, 2017 2:25 PM

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Jul 20, 2017 9:56 AM in response to RoXy1988 In response to RoXy1988

I just tried this on a mid-2010 Macbook Pro on a fresh installation of macOS Sierra. The computer had a history of water damage but there was no damage visibly obvious on the board. It had been examined by Apple several years previously when water damage had occurred. The computer had sat for a year or two without use and had such a badly bloated battery that the touchpad was popping out of the front about an inch (hard to believe the touchpad could withstand this..). After installing a new battery, doing a fresh install of Sierra, doing a hard reset with the battery out and repeatedly resetting the SMC the computer continued to exhibit signs of SMC issues -- the keyboard backlight was vacillating between on and disabled and the computer was running so slowly when it was off the charger that it was nonfunctional. The computer failed Apple Hardware Test for sensor failure: 4SNS/1/40000001:VP0R-0.000.

I am guessing that this sensor is in some way related to the battery and how the SMC detects it and adjusts the computer's power settings accordingly. Removing this KEXT resolved all the visible SMC issues like the vacillating keyboard backlight and the slowness off the charger. The changes were persistent across shutdowns and after running the Sierra 10.12.6 update the changes remained. With the KEXT removed I haven't noticed any differences between fan operation or CPU temp in stress testing and the computer is correctly recognizing that it's running on battery when it's off the charger.

Although this fix works for the visible symptoms, Apple power components are intricate and altering SMC settings have pretty serious implications, including overusing and overheating your motherboard from a lack of proper settings. Although I implemented this I'm continuing to monitor the computer. This problem indicates a motherboard sensor or component failure. Ultimately, if you're having this issue running Apple Hardware Test or Apple Diagnostics wouldn't be a bad idea.

Apple Diagnostics is the newer version of AHT and is available on computers released June 2013 and after. You can hold down D at startup (after the screen comes on) to access either of these tools. More information on these diagnostics:

How to use Apple Diagnostics on your Mac - Apple Support

How to use Apple Hardware Test on your Mac - Apple Support

For some older computers, an external CD is required. If you don't have this CD, you can find the version of AHT that fits your model computer (7,1, 8,1, etc.) online. If anyone has similar experiences and runs the diagnostics, it would be interesting to hear the results.

Jul 20, 2017 9:56 AM

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Jul 26, 2017 6:46 AM in response to tony_stead In response to tony_stead

Thanks a lot man. It really worked. I tried many option to fix this. First i thought battery is faulty then i swapped with another one from my friends macbook pro . But no solution. But this one worked for me. Though i had to disable system integrity check from recovery mode to delete that file. But it really worked , big thanks for sharing this knowledge.

Jul 26, 2017 6:46 AM

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Oct 16, 2017 5:30 PM in response to tony_stead In response to tony_stead

It worked just fine with Sierra. Now I just updated to High Sierra and the problem came back. I repeated the process and it worked again like a charm! Thank you!

Just noticed the file in my case is MacBookPro8_1.plist and its path is slightly different:

/System/Library/Extensions/IOPlatformPluginFamily.kext/Contents/PlugIns/ACPI_SMC _PlatformPlugin.kext/Contents

MacBookPro8_1.plist to trash!

Oct 16, 2017 5:30 PM

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Question: MBP Running slow when its on batteries .. working fine when plugged to the charger ?!