Likewise, I have experienced a significant battery drain issue since installing Big Sur 11.0.1. This issue needs to be a high priority for Apple customers, because this may drive their customers to other products. I have a 2016 MacBook Pro, and I have had multiple calls to their tech support which I was finally told to send in my computer or take it to a repair center. Why should we have to take or send a device in that was working fine until their supposed upgrade that is a serious downgrade, poor form from Apple! I also have a similar complaint with there iPhone 2020 SE, extremely poor battery life, which is very disappointing from a company that everyone expects high quality for the high price of their products! I hope Apple at least acknowledges the issues and advises they are working on it. But I am sure they are worried about admitting anything, since their last issue related to purposeful battery drain issues and they were held accountable!