For a number of years now I have a MacBook Pro Silicon M1 Max. It worked beautifully.

Then, seemingly out of nowhere, I started noticing that the battery drained over night when I left the notebook somewhere, not connected to power. This got worse and worse, up until the point that I’ve had enough of it and I started doing some research.

On MacOS, the terminal command pmset -g log shows the logs related to power management. Those are quite verbose and not so easy to read, so I wrote a little tool to analyze the logs.

This was however only marginally useful. I tried tweaking the settings a little I read about (such as tcpkeepalive, one by one, but without much effect.

More digging led me to learn about Sleep Aid which displays wake events in a nicer way and also has a neat interface to change settings.

In my case, the “Wake for maintenance” option was disabled, and Sleep Aid helpfully showed in the settings interface that this could lead to frequent wake up events. Enabling the setting again did the trick, and my MacBook Pro no longer looses all of its battery during the night when it isn’t plugged in.