Anyone else having this problem? I have installed Big Sur on a desktop and three laptops. All laptops are significantly running the fan much more and (perhaps because of this) running down the battery in record time. My fairly new MacBook Air went from 100% to 7% in about 3 hours with just normal use. There are lots of annoying things about Big Sur, but this is a serious bummer!
Sometimes a fair idea is use Activity Monitor and look into probable
causes of system excess, heat from processes ~ and where resources
have been deployed in the macOS. Some third-party extras could
also cause harder-working CPUs for no purpose; and fans running.
• Activity Monitor User Guide - [Table of Contents] - Apple Support
https://support.apple.com/guide/activity-monitor/toc
Most 'mysterious happenings' go on behind magic curtain, of macOS.
Take care & good luck!
🌞🌿🎣🌤🐢⛵️🐟🐌📬
• How To Downgrade macOS Big Sur To Catalina Or Older - Macworld UK ...
https://www.macworld.co.uk/how-to/downgrade-macos-3581872/
Be sure to use an 'older backup from previous/earlier macOS' when attempting
to revert to systems before Catalina and Big Sur. ~ These both had differences to
their build, which will not allow reversion. For those whose Mac and macOS are
nearer the latest (or current upgrade) you might do OK to step back & try again.
• How to make a bootable copy of Catalina to downgrade from Big Sur | iMore
https://www.imore.com/how-make-bootable-installer-drive-downgrade
So be careful with Time Machine backups, and others; newer macOS 10.15~11.x
should have their own current backups; as older ones won't work for your Mac.
Advice has been to keep an unused copy of downloaded installer versions; may
need them for revertion later; avoid trying to download yet another same one.
Keep earlier T.M. backups from Catalina, Mojave, High Sierra; on their own USB
drives as a safer bet. (+Avoid leaving them attached to an upgraded Mac OS.)
Many ideas are out there; some from the fringe of upgrade, to revert; and may
have mixed results depending on exact version, or ones in transition. Always is
a good idea to wait at least 4 to 6 months before upgrading; esp. for workhorse
setups where you need it to 'just work'. And nowdays plan on backup T.M. from
those early macOS, to help resort to an older version, when upgrade may fail.
• Downgrade from Big Sur to Catalina, yes or no? | Apple Community (answered)
https://discussions.apple.com/thread/252095695?answerId=254018932022#254018932022
Take care & good luck!
🌞🌿🎣🌤🐢⛵️🐟🐌📬
Significant, one-time events occur after performing a major software upgrade. Examples are rebuilding the Spotlight index, and a full and complete Time Machine backup. Things will quiet down...
Thank you for your thoughtful replies. It's been over ten days, and I suspect I am fully indexed by now. The fan runs almost constantly whether I am on AC or battery. This may be unrelated to the upgrade, but the start of it was EXACTLY at the install.
I'm having the exact same problem with the battery which began pretty much exactly when I upgraded to Big Sur a few weeks ago. I would LOVE to revert to Catalina. My Macbook Air is circa 2013/2014. Is it possible that the old hardware just can't handle the new OS?
The same thing is happening to my MacBook. It’s been two weeks and the problem persists. I hope there’s a solution from Apple for this. Or is it possible to revert to Catalina?
Perhaps you've neglected to account for the higher demands a new system,
& file sorting that goes on; and the need to have the portable Mac run from
the AC power source during these loads. ~ For the CPU to run adequately, it
has to have sufficient power; battery does isn't as powerful as AC adapter.
Good luck..!🌿🐢|🐌🌻
My battery life was great, then I installed Big Sur...
