Sorry for the slow reply; I assumed I'd get an email when someone posts something to a thread I've started. I'll look into that.
Yes it might have been below freezing a few times while I was away. I was also unaware of battery heaters; the manual doesn't say that.
For my estimate I was using the number of bars in the left side of the dash screen. I didn't think this was drive range, since it gets all the way up after every charge but the drive range seems to change with the weather. Haven't had the car too long but I rarely get more than 38 miles estimated and real per charge.
So what I'm getting from these posts is that this is not normal, especially for a brand new car, so I should have it checked out. You guys agree?
Thanks!
Yanko
Normally what I have heard about is the 12V battery being dead when the car had not been driven a week or two. Others have left their car sitting a similar time or even longer with no problem so the assumption is that people who's 12V died while they were gone, the 12V battery may have been weak already.
But I can't remember hearing about the traction battery losing charge like you described in just twelve days. Some have theorized that the traction battery charges the 12V. Well actually that is true but people who have tested with voltmeters have pretty much confirmed that the 12V battery is only charged when the car is on, or if the car is currently being charged. But when not plugged in, or plugged in but not charging, the traction battery will not charge the 12V.
So one theory is that maybe you accidentally left the car turned on? I have done that myself a few times when getting out of the car but I always get alerted by beeps when I try and lock the doors. But if the car was accidentally left on for a long time this for sure would drain the traction battery. If you didn't have climate control running then I think losing half of the charge in twelve days seems possible. If AC or heat was on however it wouldn't have made it more than a few hours. And I am guessing when you got back into the car after your trip you would have noticed if it was already on, so maybe the theory is unlikely, but it's all that I can think of at the moment.
As you mentioned I don't know of anywhere that the manual mentions a battery heater that operates when it is freezing, other than in Canada their models have a batter warmer but it apparently only works when plugged in.