On Mon, Feb 18, 2013 at 1:42 PM, Roger Stockton <[email protected]> wrote: > > I think this is a completely different scenario. In the hypothetical desert > scenario, > the vehicle operator *chooses* to run the A/C; in the parking an EV on a cold > night > without plugging it in, the *vehicle* chooses to run some additional > parasitic load > without the operator's knowledge.
>From what I understand, the Model S doesn't heat the battery when not charging or powered on. The DTE indicator drops because it uses the temperature of the pack as a factor in determining remaining capacity. So if the pack cools off, the car thinks that significantly less energy is available. All that said - Broder's action of turning on the car with the heat on low to "warm up the pack" is absolutely killer. He burned away energy for no reason - had he simply driven off without trying to warm up the car, it's possible he would have made it. The simple act of discharging the cells also helps to warm them up (the reason the cell's capacity appears to drop in the cold is because their internal resistance goes up) and the DTE indicator would simply appear pessimistic. Numerous Model S owners have confirmed this behavior. Broder does appear to drive very inefficiently, though. If you look at his speed charts from the Tesla blog he appears to constantly vary his speed +- 5-10 mph except for a few short periods where he appeared to be using cruise-control. I have to wonder if he was trying to defy the laws of physics by accelerating 5-10 mph, then using regen to slow back down 5-10 mph repeatedly thinking that his regen was "free" energy... -Dave _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
