Before the 2018.28.1 firmware I was seeing 8-10 miles/day loss, after I am seeing 4-5 miles/day loss. My M3 has been sitting in my garage for over a week not plugged in waiting for a protective cover that was not installed at the factory (it has not been driven). The garage temperature in the morning is 65-70F when I close the garage doors for the day and no more than 80F when I open the doors up the next morning to cool down the garage. The traction battery could not be temp soaked at more than 80 probably no more than 75F. After I upgraded the firmware, the indicated available mileage did not reduce for nearly a full day (I have been checking it once or twice a day). However, after the first day back to what appears to be 4-5 miles a day. After considerable reading on several Tesla forums and Google, I thought I understood when the traction battery required passive/activate cooling and how the car charged the 12V battery (the two main things that would use traction battery charge while parked?). In order to try to nail down exactly what is going on I connected a Smart battery tender to the 12V AGM battery set for AGM charging mode. Verified this smart charger backs off when/if the HV contactors close and the car is charging the 12V battery via its DC-to-DC converter; likewise, verified that the charger is maintaining the 12V battery voltage at around 14.8 volts. It was my hope that all power being consumed by the parked car would be 12V power and not require any HV battery power or contactor closures (I was wrong). I am monitoring the tender power use via a Kill-O-Watt meter. I hear what sounds like pump(s) running at least three times a day and they run for at least an hour probably closer to three hours per time. When this pump is running, my battery tender has backed off (not trying to charge the 12V battery) and the HV contactors ARE engaged (ie.. I open the car door and do not hear the HV contactor engage). The only thing I can think of that would require power from the traction battery is active cooling from the AC which requires high voltage. So my main question is what is requiring power from the traction battery when the traction battery is at or below 80F? I know the car is going use power while parked but around 1KW/day seems high if the battery is within a 70-80F temp range. Thanks for hopefully letting me sleep better tonight and for any enlightenment regarding the above!! Posted this on the Tesla.com forum but it seems to have disappeared after editing the title.