It doesn't surprise me that Tesla's gurus won't talk about how they're "squeezing all the extra juice" out of their battery options. Isn't that a key differentiator and competitive edge for EV companies? Why should they give away their secrets if they're able to come up with a design and a chemistry mix that gives their cars an edge? More power to them--and those that can afford the cars!
Beth, you are right that battery technology is the crux of the matter with electric vehicles. They were more forthcoming with the roadster because it was a new thing and there was not much competition. Of course that has changed. With the roadster, the battery pack weighs 900 pounds, as I recall. It reportedly gives a range of up to 400 miles (I am not sure under what conditions). The Model S has a completely different form factor, and I expect a whole different technology. This is an area that is progressing fast.
It's clear to me. It's the little things like lower weight tires, lubes, aero, fewer gears, brake retract springs, etc that can easily double the range of a given battery.
As the battery pack gets larger it's less stressed so can put out more of it's capacity per unit of vehicle weight.
In lead battery EV's going from 25% battery/vehicle weight range is about 30 miles but with 50% battery weight range hits 100 miles as an example.
In fact the about plus 50% lead battery weight is how I'll get 100+ mile range along with the above 'tricks'. I keep the battery weight, cost low by having the EV without battery only weighing 550 lbs mostly by using a composite body/chassis that weighs 235lbs.
As I've been saying it's not so much the battery but the vehicle it's put in.
Thanks, They certainly didn't reduce weight much to gain range! But it is a $100k Luxury car.
I really can't see why most EV's need over 100 mile range when for 130lbs one can have a 35kw Lotus Range extender IIRC and get unlimited range for many $1000's less. I'm doing a 4.5kw version that weighs 40lbs in mine.
I'm all for the eff of EV drive but moderation is the smart choice.
Had they went composite body/chassis both the production line start up costs would be 1/3 and unit cost by 40% for the same performance and more quiet, stiff.
With this type of range, it would seem the EV could move beyond a second car and become a primary car. Another question, Chuck. Does passanger weight and load have much of a factor in affecting speed or range?
Tesla is no more knowledgeable than any other electric car automaker (Nissan, GM, etc) about how to get the most miles perkWhr. For electrics, which benefit from regen braking, weight is not that important, sans very hilly country, which was studiously avoided by Tesla in claiming 300 miles of range. They also did not run the heater or AC, drove at a constant speed and never opened the windows or stopped or started. Aero is important,as GM found out while developing/testing their Volt, also tire rolling resistance (use skinny , highly inflated tires). That's about it. Nothing else makes any significant diference. Tesla is exaggerating greatly any small increments they got from tweaking motor rpms, etc. That battey is off the shelf-for the 300 (ho,ho) mile range pack it contains 7600 Panasonic 3100mAH 18650NCR laptops. They are retailing for around $14, or over $106,000 for the pack.Tesla is estimated to be charging over $45,000 to their customers, which is probably about what they are buying them for. The entire battery system probably weighs close to 1000 pounds. They have a very selective warranty (they don't cover total discharge -fried battery pack) of 8 years or 150,000 miles (unlikely with capacity losses and recharging cycles of around 500).
The battery is obviously the car's fatal flaw. Imagine the resale value after 7 or 8 years, near the end of the battery's lifespan. Battery capacity losses are not covered by warranty, and Tesla avoids saying much of anything about those batteries, since anything they say will likely kill sales. If you buy a Model S avoid the "300 mile pack." Get the smallest battery pack option and wait for decent batteries (you'll need to own two cars, of course).
It doesn't surprise me that there are takers for this, even at these outrageously high prices. Consider luxury vehicle + politically correct purchase + love of technology and you've got a perfect car buy for a very select few. The fact that they sold out for that particular version just shows they didn't anticipate how big the very targeted market would be.
I have to say I'm largely in the same camp as ramon here. They appear to have thrown money and batt size at this and got a longer range (Waiting to see what some independant testing gets on that). They may indeed have a viable luxury niche, but this is a long way from making mainstream EV a popular proposition.
You keep mentioning the vehicle(s) you build/are developing. Do you have a website or such. I've long had an interest in minimalist vehicles and would be interested in seeing your ideas.
Tesla Motors’ $35,000, 200-mile electric car may not revolutionize the auto industry by itself, but it could serve as a starting point for a long, steady climb to a day when half of the world’s vehicles will be plug-ins.
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