Following the release of macOS Monterey 12.2 last month, some Mac users who installed the software update started to experience excessive battery drain during sleep mode, seemingly due to Bluetooth accessories frequently waking up the machines. The issue appears to affect Macs running the first beta of macOS 12.3 as well.
Many affected users found their Mac's battery life dropped from 100% to 0% while in sleep mode overnight. A few users tried to identify a cause in Terminal and found that Bluetooth accessories were frequently causing a "DarkWake from Deep Idle" that resulted in the Mac repeatedly waking from sleep and draining the battery's charge.
Fortunately, it appears that the second beta of macOS 12.3 seeded today may resolve the issue. In a tweet, Mr. Macintosh said his 2018 MacBook Pro that was experiencing the issue on the first beta of macOS 12.3 is no longer affected on the second beta.
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 B1 2. 12.3 Beta 2 and can't reproduce the issuehttps://t.co/XVKe0oGYtW pic.twitter.com/23g6HuPPel — Mr. Macintosh (@ClassicII_MrMac) February 8, 2022
macOS 12.3 will likely be publicly released around March or April, providing a fix for all affected users. In the meantime, users can disable Bluetooth on their Mac or disconnect all Bluetooth accessories overnight to prevent battery drain.
