macOS Big Sur battery drain issue

After 2 days after update to macOS Big Sur the problem is gone.

Looks like indeed some indexing in background took place.

Now I have slightly more than 4 hours out of 40% of battery.

My workload isn't heavy, Chrome (5 tabs), WebStorm without builds, Music and a couple of messengers.

I'm pretty happy with this result so far!

I had this issue too but it has resolved itself, as I'm sure it will with you. It's a normal part of a major OS change or upgrade. The Spotlight.app needs to make a new indexing of the system (disk) and depending on how much data you already have on your machine, this could take one or two days or it could take a week. It took about 5 days for me - I did start to panic on day 4 that it was a genuine bug but it did sort itself out. After that the battery use should return to normal.

This is the only reason the suggested 'clean install' works instantly - you no longer have have any additional data to index.

Hi all,

I reinstalled Big Sur a few days ago and my drain is worse. Initially, I got about 4 hours (not great but better than the 2 hours I got with the original install) but this has been progressively decreasing. This morning, my battery drained by 50% in under an hour. After reinstalling the OS, I gave the MBP plenty of time to 'houseclean' (even though my MBP is pretty bare). Similar to the troubleshooting I did after the first installation of BS (how ironic), I:

Reset the PRAAM/NVRAM

Reset SMC

Disabled several items in Spotlight

Ran Diagnostics (no issue)

Checked CPU usage (no issues)

Booted into safe mode (apparently that might help but I have doubts) and checked the disk(s).

Latest step:

-Disabled 'optimize battery charging' - this was suggested in a recent article.

-It was also suggested that the battery calibration may have been affected (to recalibrate, it advised to charge to 100% and then let the battery drain till the MBP shuts down). I'm not convinced this will resolve the problem and frankly I shouldn't have to go to all this trouble even if it's a major upgrade. I have not tried this step.

Hopefully some of you have resolved your issue and if not, maybe one of these suggestions will help.

Im using the MacBook Pro 2019 13 inch and i just recently bought this and i have the same issues, Last night i updated to MacOS BigSur and now i noticed that my fan is turning on so much and my battery drains to 40% in just an hour which is very very unlikely for my Mac.

It's so Annoying and Frustrating. What is the problem with this update? Im starting to regret updating.

ElevatiAnn:

When you wrote «Checked CPU usage (no issues)», did you actually see very little CPU activity?

Did you leave it the default of only Viewing “My Processes”? Or did you set the View to “All Processes”? (I usually choose All Processes, Hierarchically, so I can see what processes subprocesses are associated with.)

If you look at CPU usage, using All Processes, and find only very low CPU usage; yet your battery keeps draining quickly—especially if your battery drains quickly when your MacBook Pro (MBP) is actually turned off—then you have a problem that no software can cause nor correct!

So. I highly recommend you to carefully evaluate what is actually going on, on your MBP.

@halliday

I've been 'evaluating' thoroughly for 2 weeks now. The issue isn't my MBP - I wasn't having battery drain problems until I updated to Big Sur. My battery doesn't drain when the MBP is turned off.

I view all processes and will see a range of numbers depending on what I'm doing. Some will be low while others will be higher.

ElevatiAnn:

It is good that your «battery doesn't drain when the MBP is turned off.»

At least that eliminates certain, potential, hardware issues.

However, if you see nothing significant using CPU time, when viewing All Processes, then the problem cannot be software.

So. Make sure whether you are in this situation!

I have a Macbook Pro 2019 16" and use my notebook in two locations. On the second location I use a Hama 65 Watt power supply. Since switching to Mac OS Big Sur, this one is no longer able to charge the battery.

georgios176 wrote:

Thanks for your post. But, how is it to explain that after completely reinstalling OS Big Sur, and I mean after erasing all data and installing everything new, the drain still occurs?

If you truly «erasing all data and installing everything new» and you didn’t install any other software nor migrated any of your data, then you should experience the same as others that have done the same: very little activity in a short amount of time.

If you don’t experience that, when you have nothing but a clean install, then you have something else that is wrong.

So. You need to be careful in your analysis and evaluation.

Hi @Halliday -

So, I've been upgraded to the 'senior 'advisor' category with the folks at Apple. I'm "hopeful" that we can figure out what is actually going on. As I mentioned previously, the issue doesn't seem to be HW-related but frankly, after 2 weeks of doing everything I can think of, I'm at a loss. For example, yesterday's trouble-shooting led to my battery lasting.... 7 hours (!) so I was excited. However, upon boot-up this morning (at 100%), it took less than 2 hours to drain by 52%. Needless to say that now, I'm just aggravated.

:-)

I’m glad you are working with a «’senior 'advisor'» «at Apple», ElevatiAnn.

I hope you’ll cooperate with them, and that you will try hard to be very clear about what you are experiencing.

Unless technical people can be completely clear about what you are actually experiencing, they can neither help you, nor can they solve any such issue for other users.

Umm, I've been pretty thorough and clear with Apple about the problem. Short of drawing them a picture, there's not a lot more I can do. I work in IT - so while users need to clearly outline their issue(s), the vendor is equally responsible for clearly and precisely informing users about what THEY need us to provide them. It's a 2-way street. I don't see why anyone would create a case or open a support ticket if they weren't planning to 'cooperate' in resolving their issue.

I quite agree, ElevatiAnn, that «It's a 2-way street.»

That’s why it is usually a dialogue, rather than discourse (one way communication).

I was simply pointing out that purely verbal (and, even worse, purely textual) communication is fraught with opportunities for miscommunication.

Additionally, sometimes, those in information technology (IT), when needing technical support, can be like Doctors as patients.

My problem about this draining issue is that:

I usually don't shut down my macbookpro when I sleep. So I just set it to sleep overnight. HOWEVER, after updating to BigSur, it appears that around early morning maybe 7:30-8:00am the fan starts to make a noise even if the laptop is set to sleep AND the lid is closed. If I try to wake it by pressing a key, nothing happens, not even if I press on the power button. So, I have to plug in the power just so It would "start".

My battery indicator is normal.

Is my laptop waking the system on it's own? I did not set the start-up schedule. wake up on network access is off, etc. messages, facetime, are not enabled so my usual texts or call will not wake the laptop.

MacBook Pro (13-inch, 2018, Four Thunderbolt 3 Ports)

My experience was the same as well and with multiple calls to Apple Support, I was eventually directed to the local Mac Shop, where I had them wipe my 2019 Macbook Pro and reinstall Catalina. My laptop was running hot and draining the battery the same way that your and thousands of others here have mentioned. Until there is a software fix coming from Apple, I believe this issue will persist. So, after spending $50 and reinstalling apps and data I am back up and running. Good luck!