I had it even worse only 5 hours of battery life in my first week of usage. It turned out OneDrive had a bug with syncing; after reinstalling (then keeping it on overnight for the sync to finish), the battery jumped to ~8-10 hours with fairly heavy usage (Parallels + Safari, though with syncing paused), which is near your current level. The Energy tab of the Activity Monitor helped me identify OneDrive as the power suck.

The task manager (called activity monitor) has a power usage section. It might be syncing or if you had Firefox on it uses way more than safari.

How are you measuring CPU usage? Presumably whatever monitoring tool you're looking at needs to redraw itself, and that's going to bring in WindowServer…

(FWIW, my WindowServer usage is generally around 3-8% when idling and I am losing about 6% an hour at the moment.)

Perhaps you have some rogue process that is causing windows server to run at 4%?

Any chance you have Dropbox running? They are very slow to native M1 support and otherwise their app manages to really kill battery life.

I’m actually debating if I even want to do a backup and restore because of this. I don’t want my chimera of an environment.

I think I want to just use this machine fresh and just move a few files over as needed.

Any background process running through Rosetta, like dropbox, or maybe your Windows server, will eat up tons of battery if they’re not running native.