I was recently in Activity Monitor checking network info when I noticed that powerd was using an inordinate amount of CPU time on my macbook. It’s a little odd for the power management daemon to be the source of a power problem!
After poking around a little more I noticed that the activity monitor stores power consumption infomation and the light switched on in my head. A quick look at top confirmed my suspicions.
The reason powerd appears to be using a lot of CPU time is because when you have activity monitor open it’s querying it for power information. So if you suspect powerd is using a lot of CPU time I suggest closing Activity Monitor and using “top -o cpu” instead.