So, Apple has borked their latest MacOS update badly it appears.
From Macrumors:
Affected users say their Mac’s battery life drops from 100% to 0% while in sleep mode overnight since updating to macOS 12.2. A few users tried to identify a cause in Terminal and found that Bluetooth accessories are frequently causing a “DarkWake from Deep Idle” that results in the Mac repeatedly waking from sleep, which drains the battery. The issue appears to be affecting both Intel-based Macs and M1-based Macs.