Twice in the past couple of days I found my MX-980 completely void of any power b/c I left the USB cable plugged in for a few hours. Isn't this kind of the opposite of what should happen, considering USB provides power?

I didn't not expect the USB to charge the MX-980, but I also do not think it should drain it. FYI, the battery was fully charged before plugging in the cable, and it only took a couple of hours to kill it.

From what I've seen, when it's plugged into the USB it does not charge and the back light stays on the entire time too. It does drain the battery per the indicator while plugged in.

Ken

my 950 drains very fast when I am constantly making adjustments and the 3000 I programmed today did the same thing

This is precisely why I only plug it in when I am testing codes or downloading to the remote. I agree, though, that it is strange for something to LOSE power while plugged into the USB port.