I wanted to provide an update on the car as promised.
I got back last week and it looks like you guys were right. The car had just gone into deep sleep and had completely shut down (?) the main display unit preventing connectivity. When I got to the car, the main display required a hard reboot to wake up and the car had put itself in jack mode and it briefly said smart air suspension not available. The car took a long time to wake up and get back to normal but other than that, everything was okay.
As I mentioned previously, the car was set to charge to 70% (149 miles rated) when I left on the trip and had around that much range when it went offline on Oct. 27th. When I returned on the 14th (19 days after car went offline), the car had 111 miles of rated range remaining (52%). This equals to around 1% or 2 miles of range loss every day (I have a SW restricted 60D for reference). Which is perfectly in line with what you guys had said would happen. So it seems that I did not have any real cause for concern.
However, it did make me question why I was seeing a huge range loss per day (I had estimated 4-5%) when the car was left plugged in and I left on long road trips. And the answer is, surprisingly simple. I was wrong.
Looking back at the data I have from my charger, it looks like I was only losing 2% (4 miles) of range per day at most when the car was still online and charging every day. I partly calculated my usage wrong AND I was partly looking at energy usage at the plug (not at the car) to determine how much energy I was losing every day.
Which brings me to some interesting data that I think you guys might be interested in.
Looking back at the data from earlier this year when I left the car plugged in and travelled for approx. 2 weeks, I realized that, the car uses way more energy when plugged in than when not plugged in. I know this seems like a "well, duh!" statement but the emphasis is on
way more energy.
How much more? Attached is a screenshot of the energy usage I got from the charger from my last trip. For a trip of 15 days,
the charger dispensed 23 kWh of energy when the car was not at all being used.
Keep in mind, the usage shown is at the plug and not in the car. Based on the charger losses (calculated at 78.24%), the
car gained approx. 18 kWh of energy or approximately 30% of the rated capacity.
If, on the other hand, I had left the car unplugged and the car had gone into deep sleep like it did on this latest trip,
it would have lost only 9 kWh of energy and would have used
11.5 kWh at the charger saving me another 11.5 kWh in energy usage.
This brings me to another question for the community.
I know Tesla advocates for the car to be left plugged in any time its not in use. But what are the real benefits of doing that? Looking at the data, I'm tempted to leave the car unplugged when I travel so that I can cut the energy usage in half unless there are some serious disadvantages in doing that.