I put the power setting for the hard disk to turn the power off after 5 minutes. I have an X25-M that is idling. The power on count increased for X25-M, so either something unbeknown to me was accessing the X25-M and preventing it from going to sleep, or power on hours are still recorded when the drive is "powered off".

Kind of strange that the V3 has to be fully powered up to count LLT hours and presumably run GC background tasks.