@ixu , @andy , comparisons for an AC garage door opener here.
Sense detects most openings and closings, but I slapped a smart plug on a couple of mine anyhow, just to study differences. Mine use about 420W for the entire length of door travel, with very little difference between ups and
down “lifts” - more about friction and motor loss vs net door weight.
Plus the Sense native detection misses standby Always On power plus the short term LED light cycle coincident with the door open / close (20W)
Andy, I can see how detecting a DC motor with battery backup could be very hard - I’m betting the power waveform going into the opener is far different than the energy waveform used by the DC motor.