Macbook pro 15 inch mid 2014 Random shutdowns on battery

[Sebasboy]

hello good day. i've recently picked up a 15 inch mid 2014 macbook pro for cheap to give to my mother as she still rocks a 2007 macbook pro.


but it has a weird issue. whenever on battery power. it randomly shuts off without any clear reason to why. it is a instant shutdown. there is no hang/freeze or any other indication before it shuts off. it's as if the battery is yanked.


it takes a little moment. but when it finally turns on again. the date and time has been reset, as if the battery has been disconnected out of the blue.

it works perfectly fine while plugged in. not a single shutdown/hang/issue.


it's not a consistent trigger. sometimes it would shut off opening safari. but other times it would run cpu+gpu stress tests off the battery for a while before randomly triggering the shutdown.


i did do a full OS install on battery while driving back home. and it didnt shut down once (mavericks internet recovery. mavericks also had 0 shutdowns during my usage)


the issue happens on both the original battery and a brand new battery.


i'm currently running big sur. but issue also happened on somora (ocpl)



I read online about a potential issue of the thunderbolt chip having issues. so i've tried disabling the thunderbolt kext. the the issue appears to still be present.

i've currently disabled turbo-boost for the cpu. and it has not shut down once on battery so far. (potentially a cpu fault then? sucking too much power? i noticed a 96 watt TDP limit...)


what could the potential issue be?

i've already repasted the gpu and cpu twice. i also made sure to leave the PCH without any thermal-paste the 2nd time i did it after people commented on that.

thank you in advance for any advice!

 

[MRxROBOT]

If it works fine when plugged in, but starts shutting down as soon as your on battery power then its likely a bad battery. Use coconut battery to check the battery health.

coconutBattery 3.9 - by coconut-flavour.com

With coconutBattery you are always aware of your current battery health. It shows you live information about the battery in your Mac and iOS devices (iPhone, iPad)

coconut-flavour.com

I know you said that you checked with a brand new battery, check the health anyways. Could be faulty new battery.

 

[Sebasboy]

If it works fine when plugged in, but starts shutting down as soon as your on battery power then its likely a bad battery. Use coconut battery to check the battery health.

coconutBattery 3.9 - by coconut-flavour.com

With coconutBattery you are always aware of your current battery health. It shows you live information about the battery in your Mac and iOS devices (iPhone, iPad)

coconut-flavour.com

I know you said that you checked with a brand new battery, check the health anyways. Could be faulty new battery.

health status of both the new and old battery are good according to coconut.

the old battery had around 600 cycles. it just didnt last as long. + a fresh battery never really hurts for these machines..


when i opened and worked on the macbook. besides minor dust on the edges of the fan. that thing was spot clean inside. along with the near mint outsides (besides 1 single tiny dent)

it leaves me to believe this mac was mostly used in a very clean environment. and mostly connected to the charger with occasional charge cycles. (the cable is absolutely knackered though. will buy a new 85w charger..)

and it's weird that it's so inconsistent. on the attached video. it ran the cpu test for a while. then finally shut off.

but then it runs games perfectly fine if i unplug it during the game and then let it drain 20/30%.

 

[Sebasboy]

If it works fine when plugged in, but starts shutting down as soon as your on battery power then its likely a bad battery. Use coconut battery to check the battery health.

coconutBattery 3.9 - by coconut-flavour.com

With coconutBattery you are always aware of your current battery health. It shows you live information about the battery in your Mac and iOS devices (iPhone, iPad)

coconut-flavour.com

I know you said that you checked with a brand new battery, check the health anyways. Could be faulty new battery.

small update. some more tests done.

ran unigine valley benchmark with turbo-boost disabled. charged the battery while running benchmark on infinite loop from 50% to 100%.

then i unplugged while the benchmark was on. i let it go down to 65%. then i re-enabled turbo-boost. and within 15 seconds the laptop shut off instantly.

so it has something to do with power draw OR the cpu/cpu power delivery?

either way for now i'll just force disable turbo-boost forever. then it shouldnt shut off.


it wouldnt be too much slower anyways.