Thursday, March 13, 2008 7:42:03 PM
Having checked responses from Tesla staff to questions on their website, I see that the correct figure is 53KWh, not 58KWh. Which means that the Tesla at full power will completely drain its batteries from maximum charge of brand new batteries in 16 minutes 18 seconds.
Also, the charge time isn't necessarily 3.5 hours with the special charger - it can be up to 5 hours, depending on how warm it is in your garage. The charging generates heat. Cooling will come on if there is too much heat, but of course that takes power from the batteries and thus increase charging time.
Thursday, March 13, 2008 4:48:11 PM
I'd like to see a "well to wheel" efficiency comparison between an efficient diesel-powered (diesel car engines are 30% efficient in practice, with a 56% theoretical maximum) two-seater car carrying one person and no luggage/shopping/etc and a Tesla in various areas.
I doubt if the difference would be much. The main gain is emissions in areas where there`s a lot of electricty generated from solar/hydro/geothermal/etc.
The compressed air engine is also interesting, though not yet practical. No batteries - electricity drives a compressor which "charges" air bottles (like scuba diving kit). That makes it possible to "refuel" in minutes at a station - you`d just swap your empty bottles for full ones or even, possibly, refill using a compressed air line. That would make "refueling" the car as convenient as refuelling a petrol or diesel car and vastly better than recharging a battery car.
Thursday, March 13, 2008 4:35:26 PM
Safety is an issue too, by the way. They're extremely light, which lowers their crash rating even with the materials used. As for the statement that the 7000-odd batteries are protected like nuclear material is in transit, that`s a bit silly. Weight rules that out.