I haven't studied this report in detail, but I feel like I must be missing something. Looking specifically at cooling for the LEAF, the range advantage of precooling is less than 2%. The only real kicker here seems to be their claims about battery life. Here their numbers seem quite suspect. Is it really likely that precooling a 95 degree cabin for ten minutes would reduce a 95 degree LEAF battery pack to 80 degrees if the outside temperature is 95 degrees? I'm no expert on thermodynamics, but I am visualizing a heavy flat block of material with no active circulation exposed to 95 degrees on one side and maybe 75 degrees on the other side. Run the precooling for an hour and you might get down to 85 degrees, no?
Apart from my skepticism on that, my real personal problem is that the only time I might encounter a situation like that is in the afternoon. And in the afternoon (at least on summer weekdays) my electric rate is between two and three times as high per kWh as at night when I charge the car. If I'm going to precool I'd rather do it with cheap electricity, i.e. not plugged in. Driving the car can use bursts of up to 80 kW (though not the way I drive), but cooling it seems never to use more than 5 kW. Is a 5 kW draw on a hot battery going to be as hard on it as a 50 kW draw?
And, by the way, the real bottom line here seems to be that if you are going to be driving your car on a hot day it is far better for the battery if you DO have the A/C on, so it can help keep the battery cool.
End of April 2013: Traded my 2011 SL for a 2013 S with charge pkg.