Greeting fella Big Sur users! After the update I notice a HUGE difference between my previous (macOS Catalina) and latest (macOS Big Sur) battery drainage. My battery health lost 7 percentage immediately and the battery is draining 3x times faster than before. Example: I use the Preview all the time to open pdf files. I monitor my time on the MacBook and most of the time on 70 percent I had roughly 13:42 hours left. Now the (after the update) time reduced to 4 hours or so. I also compared battery drainage on both OS and Big Sur is eating a lot more on the same config. (2019 13 inch stock MacBook ) I'm looking forward to any suggestions or solutions!

Greetings Big Sur users! I've written a post before about this topic and the problem isn't resolved as I expected. Following the methods I've found on the official community page of apple and from 3rd party suggestions I came to the conclusion that it's way deeper in optimization of the OS. I've reset the SMC, PRAM/NVRAM and run Diagnostics (at the request of Apple Support) - no issues to report except that now I can't access recovery mode which would be necessary to reinstall the OS. I almost always see the 'Using significant energy' alert when I'm using Safari - which is always, however at most, I've got only a few tabs open (not more than 3). I'm not running any other applications, since. Many suggest to disable the ¨Spotlight app.¨ for most categories (this got me less energy use in general from the battery). Some others who are using Chrome or any Chromium based browser faced issues with ¨Chrome Helper¨ constantly running in the background without the Battery Monitor showing its significant drain - stopping this process (from the Activity Monitor) gave most users a better image of their battery time. (I use Safari so that's not the case for me) In conclusion of trying every method suggested, I would like some response from the Users and Apple himself about this topic. Thank you for your attention!