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macOS Mojave battery drain

Just updated my OS to Mojave this morning and brought my laptop to work. It was on full charge when I left home. 2hrs after using it, the battery percentage was down to 40% which never happened before during any of my regular use. Also, the texts on the screen are blurry.

MACBOOK AIR (13-INCH, 2017), macOS Mojave (10.14)

Posted on Sep 25, 2018 9:17 AM

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743 replies

Oct 4, 2018 4:48 PM in response to hvbris

Same here. Battery life is terrible now. I can barely get two hours out of it and it shuts off when it gets to 35%. Start up is wonky, too. Two thirds of the way through the progress bar of start-up the screen goes black and I get the dreaded beachball for about 20 seconds before the desktop launches. Then, it reverts my desktop image to an older one. Weird. NONE of these problems occurred before the Mojave install.


I tried resetting PRAM and the SCM, both. Neither process fixed the issue.

Oct 5, 2018 5:08 PM in response to hvbris

Me too. 2015 13" MBP, Charged 100% last night. This morning I opened the lid to find I only have 60% battery after 8 hours. Never happened before. Similarly, I have wifi issues connecting (or not) to different networks after upgrading - but I'l post that comment in the wifi discussions.

Apple - we need a patch for wifi and battery drain please.

Oct 6, 2018 2:30 PM in response to hvbris

I am experiencing this issue as well. It appears to be the kernal_task process that might be the culprit. I noticed my 2018 MBP was hot inside my bag after only a couple of hours of what should have been in sleep mode in my bag (I do not have power nap enabled when on battery). When I pulled it out, I immediately opened activity monitor and saw that kernal_task was using as much as 800% CPU (generally 100% CPU equates to full utilization of 1 CPU core/thread, so in the case of my 6 core i9, I could potentially get to 1200% since it has hyper-threading). That type of CPU usage would be extremely heavy type use, so there is definitely something wrong.


This needs to be fixed ASAP because the heat being produced doesn't seem to be tracked by the OS. Once I opened my MBP, it realized it needed the fan and kicked into high gear. This issue could result in CPU, logic board, battery damage and other things. It has already resulted in a few unnecessary cycles for my battery.

Oct 8, 2018 2:06 PM in response to hvbris

I have encountered the same issues. I have a MacBook Air 2017 and the battery drops 21% after whole night on sleep mode. I have done some research and saw a solution provided from Apple tech. I tried that solution and the battery issues is gone.


The solution is resetting SMC and PRAM.


1. Reset SMC:

- Shut down MacBook

- In shut down mode, press "shift-control-option-power" key together for 10 seconds

- turn on power


2. Reset PRAM:

- Shut down MacBook

- right after press power button, quickly press "option-command-P-R" key for seconds until it reboots again, then you can release those keys.

- Let it reboot and run to system login


Those two steps should resolve the battery drain issue.

I did those two steps and my battery drain is back to normal rate.

Oct 9, 2018 7:04 PM in response to hvbris

I updated MacBook Air to MacOS Mojave when it became available. In several days, my battery started die in 4-5 hours. Then, notification about battery health appeared(computer is pretty old so it is logical).

Now, it is alive only for 3 hours. Before new macOS, it was alive for at least 8 hours. Maximum capacity of the battery decreases rapidly. 2 days ago it was 4800 mAh, whereas now It is 4300 mAh.

Don’t want to become that Windows guy with charging cable tail...

macOS Mojave battery drain

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