HiR Information Report: OpenBSD Power Management
OpenBSD's power management features are powerful and plenty. My current setup floats the battery at 80% charged, to reduce battery wear during the work week, and it doesn't suspend when I close the lid as long as it's plugged in. On battery power, it adjusts the CPU speed under load to optimize battery life without sacrificing performance when I need it, and it will automatically suspend at 5% battery to save me from the system powering off unexpectedly. When I plan to head out, I can use a quick alias to allow the battery to charge all the way, which takes about 20 minutes from 80%. We'll go through how I have it set up.
Long-time readers of HiR will not be surprised I'm running OpenBSD as my primary general-purpose operating system on my ThinkPad X1 Carbon. Over on Instagram, people do a double-take. One of the surprises was the fact that in a NeoFetch screenshot, it was noted that my CPU was 400 MHz because I was on battery power without anything heavy running. Power management on OpenBSD also blew some minds.
Out of the box, power management is disabled on OpenBSD. It's one of the few things that do not "just work" by default. The vast majority of OpenBSD systems do not need power management features, but it's a must for laptops.