macOS Big Sur 11.3 Battery Drain

I think for me I have found the issue:

I use Sophos Home Premium and on their support site I found following message: Mac user seeing High CPU usage caused by SophosPrivacyGuard? We are investigating. You can turn off this protection as a workaround. See: this article

I am experiencing the spotlight indexing stopping Time Machine backups also on external disks connected via USB and formatted as APFS.

I am gonna describe again the behaviour:

1) A Time Machine backup starts (either automatically or manually), NO MATTER if the target is a network volume or an APFS formatted disk connected via USB

2) The backup doesn't complete, it gets to 50%-70% and then gets stopped by Spotlight (clearly stated in console messages: MDSYNC process stops the backup)

3) The cleanup process in Time Machine preference pane seems to go on but its indicator doesn't advance, after a while it seems to finish (I couldn't yet understand if the cleanup has been really done or if that was stopped too)

4) Spotlight starts to re-index the entire backup volume/disk from scratch: A bunch of MDWORKER processes can be seen in Activity Monitor and by checking on their info panel the open files I could see access to the backup volume/disk were made.

Clearly this thing contribute to battery drain especially when the disk is a network volume.

5) Trying to backup to the same volume/disk again right after the pattern just described means going back at square one of this pattern.

Attempts done to mitigate the problem:

1 - Spotlight re-index of the whole internal disk -> didn't solve it.

2 - repair network backup volume via Time Machine menu item option (option-click TM menu item) -> didn't solve it.

3- reapair via diskutility internal disk and backup volume/disks either in recovery mode or while logged-in normally -> didn't solve it.

4 - Ditch TM backup for a new one -> partially mitigated the battery drain since Spotlight won't have to re-index many older backup snapshots. Problem not solved though.

5 - Booting in safe mode and then running the TM backup: backups are done as before the 11.3(.1) update(s), no weirdness with Spotlight re-indexing.

Regarding this last thing and before someone jumps to conclusions about malware or other weirdness:

I don't have any illegitimate daemons or agents in both /Library/LaunchAgents and /Library/LaunchDaemons: iStatMenu, Adobe Creative Cloud, BlockBlock, CarbonCopyCloner, LittleSnitch, Whatroute and Epson software update (should be epsonercp).

All of these updated to the latest versions.

Both /System/Library/LaunchAgents and /System/Library/LaunchDaemons seems legit too, containing only Apple's agents and daemons (plus openssh, apache, etc.).

I have asked cause I am having the following issue which is draining my battery faster (but my Time Machine backup is on a NAS): Time Machine doesn’t finish its backups getting interrupted by Spotlight, which then keeps the TM disk image mounted and starts to re-index it.

I got rid of the TM backup I had since prior this last Big Sur update, in favor a new one, but the problem reappeared.

Perhaps you want to check if that is happening on your system too.

I am having this Time Machine/Spotlight problem on two machines: an M1 MacBookPro and an Intel Based iMac; both are using the same NAS for Time Machine Backup.

To check it out you might as well open Console application and filter the logging stream by using “backup” in the search field. Then start manually a time machine backup and check the logs.

Also you want to check via Activity Monitor.app if Spotlight starts to index the backup disk like **** as the TM backup is finished, filtering the active processes using “mdworker” key: in case you’ll spot a bunch of “mdworker_shared” processes, chances are that is the battery draining problem.

Before you retire for the night, shut down all MacOS applications, turn your power-management to always on, plug the laptop in and leave it running overnight.

When doing a major OS upgrade, MacOS will do a lot of system processes the first day. While it's difficult to know what your particular configuration is, at least let MacOS finish up its processes.

I don’t use Sophox, nor it seems the user who opened this thread uses it or is the cause behind the draining of his battery.

Look at the screenshot he had posted, and you’d clearly see that in his case Spotlight had been draining more battery than Zoom.

In my case if I switch off automatic TM backups, I won’t get abnormal battery draining cause Spotlight won’t go crazy re-indexing the backup volume after each backup (meaning intensive networking and computation for the indexing every hour no matter how much data has been backed up prior Spotlight stopping TM operation).

I’ve had this problem since the update to 11.3 done around 10 days ago (as it was released).

11.3.1 update has not mitigated it.

I’ve rebuilt Spotlight index plenty, ditched the TM backup and started fresh 3 times, left the laptop plugged in all night (on caffeinate command via terminal to prevent sleep) in order to check if after having re-indexed the backup volume more times it would have finally stopped with this behavior: no result with that strategy too.

I didn't imply it was the Sophos agent causing it. I simply stated that 3rd party AV/Firewall products should be uninstalled as they cause more harm than good.

I also mentioned in an earlier post that when doing an OS upgrade, many times there's a lot of background tasks running, including indexing that chews up a lot of CPU/battery and depending on how it's being used it may take a while for it to complete. When I get similar behavior after upgrading MacOS, I simply leave it all (and plugged in if a MacBook) and walk away from it at night and let it finish its housekeeping overnight.

I've had similar behavior happen on older iMacs. Letting them run overnight while I sleep usually takes care of it. Not saying that's the fix for the OP, but it works for me.

I updated it to 11.3.1and it got fixed. Battery backup is good now. I’m not facing any battery drain since then

Hi there, Percival876! Thanks for reaching out to Apple Support Communities. 

After reviewing your post, it sounds like you are running into some battery drain issues after updating. We definitely understand that can be a concern and we'd love to help. Let’s start by reviewing the following articles to check on things further:

• Check the condition of your Mac notebook’s battery
• Monitor your Mac notebook computer’s battery
• Get help with your Mac notebook battery

It’s also a very good idea to make sure to restart your Mac after an update ( Log out, sleep, wake, restart, or shut down your Mac ) and update all of the apps on your Mac ( How to update the software on your Mac ).

Please let us know if you have follow-up questions about this issue, or if the issue remains unresolved. Have a great day!

Same as above: just turn off TM backups when on battery, rather than rolling back to a previous version of macOS.

Mine is doing the same, I tried all the recommended steps listed above with no resolve. I charged it yesterday, closed the lid and went to bed, Macbook Pro was dead this morning. I did not even use it! I have looked at the battery condition, it is good. There are no apps hogging the battery that I can tell. This is awful, can I revert to the previous version?

After Big Sur 11.3.1, my MacBook Air M1 16GB RAM/1TB went from maintaining a battery charge of 100% for nearly an hour to dropping 10% in the first 30 minutes of unplugging it. It went to 99% in 30 seconds, 98% in 2 minutes, was down to 95% in 5 minutes.

The battery performance has slipped badly since this update. It's now worse than my 2017 Macbook Air running Mojave. Alarming.

I am running Firefox - one browser with 9 or 10 tabs open. No heavy lifting, just browsing the web.

The one item that might be highly suspect is Adobe Creative Cloud which runs in the background. It has notoriously been problematic, but it has been become increasingly so since updating to 11.3.1. Even quitting ACC does not impact positive battery performance.

I use a Sophos XG115 to run my home network and I have the firewall handling all that. I don't install any 3rd party firewall/Anti-virus on my Mac simply because they cause more harm than good. Not saying that's the issue but when people complain about the performance of their Macs, we always tell everyone to remove all those invasive programs. They don't really improve the security of Macs that offsets the problems they create.

This issue can be solved only one way like i did , rolled back to Catalina. It's some problem with BigSure not MBP.

This morning it went from 100% to 85% in 15 minutes. Alarming.

I rebooted and disabled Siri. Yesterday it was at 100% for almost an hour, and performance was excellent. No change in tasks/workload for the device.

Apple please fix this!

My 2019 MacBook Pro, i9 has about 1/3 of the battery life it had prior to the 11.3.1 update. It also logs me our when it sleeps after this update, unless I disable power nap. All of the Mac OS bugs with recent updates makes my Windows box look better and better.