The latest macOS Monterey 12.2.1 update claims to have fixed excessive battery draining for MacBooks when they are in sleep mode.
While the release notes (opens in new tab) for 12.2.1 update don't mention battery drain directly, The Verge (opens in new tab) posted a screenshot of the update which states it fixes "an issue for Intel-based Mac computers that may cause the battery to drain during sleep when connected to Bluetooth peripherals."
Multiple users on macOS Monterey 12.2 previously noticed that their machine's battery would drain from 100% all the way down to 0% while in sleep mode. Some then reported that turning off Bluetooth seems to fix the problem, and Apple's update pretty much confirms Bluetooth was the culprit.
Apple noted that the issue affects Intel-based Macs, however, we've seen users complaining that MacBooks with the Apple M1 chip were also affected.
But Twitter user Mr. Macintosh (opens in new tab) noted that the macOS Monterey 12.3 Beta 2 appears to tackle the problem as well; just be aware that this version of macOS won't be available to anyone not in the beta program.
From what I can see, macOS Monterey 12.3 Beta 2 (21E5206e) fixes the Bluetooth battery drain issue.I tested 3 times & didn't see a single DarkWake 👍Test setup:1. 2018 MBPro that had the issue on 12.3 B12. 12.3 Beta 2 and can't reproduce the issuehttps://t.co/XVKe0oGYtW pic.twitter.com/23g6HuPPelFebruary 8, 2022
In any case, we recommend you make sure you are running the latest version of macOS on your Mac machines.
To do this go to your System Preferences and click on Software Update. You should then be able to refresh the page and install the 12.3 update by selecting Install now in the pop-up window. Once done you're good to get back to whatever you use your Mac for.