Same here, I have noticed since d/l Big Sur the battery is draining a lot faster on my recently purchased MacBook Pro (15-inch, 2019).
I also had a few other problems which have mainly been sorted since resetting the SMC, i.e. upon opening a web page it always gave the message "you are not connected to the internet" (but I was), and, fingerprint stopped working. The problem with Apple is they obviously don't test rigorously enough before releasing these updates, and, the problem with me is, if it's new I just HAVE to have it, so I go on full steam ahead but I should check forums first to see if there are any problems. DOH!
artcev40
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution
From
England