On the Model S I've been wondering about the length of time a full battery charge can carry the load of the air conditioning for a sitting vehicle? I know there are many variables (Battery Pack capacity, Temperature delta, sun vs shade, humidity, # of occupants, etc,...) involved but any anecdotal examples, or load calculations would be appreciated. Thanks!

I've never seen it draw >3kW for the AC (cooling) so even conservatively assuming ~60kWh usable that's ~20 hours. ~1kW draw and ~75kWh is more likely so ~3 days

Thanks Guys, appreciate it. Any figures available, by chance, on the BTU output of the Tesla Model S AC?

Appreciate the response, but as a straight energy conversion, that's not quite what I'm looking for. We know that the system will not be 100% efficient, and most automobile AC systems are grossly inefficient (don't really know about Tesla's). Was looking more for any published specs that indicate the rated cooling performance capacity of the Model S cooling unit. But appreciate the assist all the same.

Air conditioning is usually far more than 100% efficient. They are heat pumps, so this is not a violation of thermodynamics. For one joule of energy expended by the unit, it can move multiple joules of heat outside. Typical real-world efficiency is something like 2-4x the input energy.

I was sitting in the car for an hour the other day in the parking lot for an hour with the AC on (and the radio off, but GPS on) and my range distance reduced by 2 miles.