Where is this battery draining code from?

That's interesting - maybe something is trying to repeatedly buzz but with an empty pattern so you don't see it.

You could try connecting with the IDE and doing require("buzz").pattern = function(p){print("BUZZ",p);} to see if it's being called a lot - or maybe one of the patterns is just causing it to repeat constantly?

Also, Is it possible you have this option enabled in the App Loader:

Minify apps before upload (BETA, not recommended. Uploads smaller, faster apps but this may cause some apps to stop working)

If so, it might be worth unchecking that and doing Reinstall apps which should replace all your apps code without deleting any data files.

The Minification option seems to have caused a huge amount of issues so far and it wouldn't surprise me if it ended up causing some