May 4, 2007 1:19 PM PDT

Silicon Valley engineers peek at the Tesla

MENLO PARK, Calif.--If you want to pack a room of mechanical engineers in Silicon Valley, just trot out its hottest new symbol of status and geekery, the Tesla Roadster.

Tesla Motors, maker of the electric-powered sports car formerly code-named DarkStar, showed off the Roadster's second engineering prototype here Thursday evening at a networking event of the American Society of Mechanical Engineers. Perhaps even more compelling for the engineers than to see the car was the chance to pick the brain of Doug Bourn, senior electrical engineer for Tesla, who tried to illuminate the inner workings of the Roadster to a sophisticated crowd.

Jean-Claude Roy, an engineer at Lockheed Martin, said: "Of course, this car is too expensive, but I wanted to understand it."

Tesla's first $92,000 two-seater sports car is expected to ship in November or December of this year, according to Bourn. Among the first 180 owners of the Tesla--125 of whom paid in full up front--will be Google co-founders Larry Page and Sergey Brin, who invested in the San Carlos, Calif., company.

Bourn touched on everything from the high-level thinking behind the car's development to the nuts and bolts of how it works, including describing the battery pack. He likely fielded some questions he didn't entirely know the answers to, given his curious audience of mechanical engineers who wanted to know some things that fell outside his field of expertise, electrical engineering. (Bourn worked primarily on the car's power module.)

The idea behind the Roadster, Bourn said, was to minimize resource consumption per mile, emit low carbon emissions and get away from America's destructive oil diet--all without sacrificing performance. And the company has done that: The car can accelerate from 0 to 60 mph in four seconds, topping out at about 130 mph. It runs completely on electricity and plugs into an electrical outlet in the wall, giving the car's battery a range of up to 250 miles, according to Bourn.

He offered efficiency comparisons of battery-powered cars versus other alternatively fueled cars. For example, his equation factoring how far a hydrogen-powered car could go on 1 megawatt hour of electricity showed that it would go about 1,800 miles, considering that efficiencies are lost in the conversion of producing hydrogen in a fuel cell. In contrast, the electric car can go 4,900 miles on 1 megawatt hour of electricity, according to Bourn's calculations.

Part of the car's secret sauce is in relying on lithium ion cells, commodity batteries that are commonly used in laptops. Using many small cells, Tesla has built its battery pack with 11 individual sheets of 621 cells. Each sheet has a semiconductor chip evaluating the cells for charge balancing and cooling, and the pack has built-in safety features so that if one cell were to spoil it would shut itself off so as not to degrade the rest of the car, according to Bourn.

Photos: Under the hood of the Tesla Roadster

The entire stack weighs about 950 pounds and packs higher energy density than previous electric cars like General Motors' EV1. The EV1 had an energy density of 300 kilowatts per hour, compared with the Roadster's 580. The company guarantees the life of the battery pack for 100,000 miles. Tesla hasn't established a cost for an extra battery pack yet.

Other details Bourn offered: The car weighs about 2,600 pounds. It has a carbon fiber body and a bonded aluminum chassis. It uses all LED lighting, with a 12-volt electronic system. It uses only rear-wheel drive and might not be ideal for a winter jaunt up to mountains given that chains wouldn't fit in its tire well.

Right now, the car's undergoing all of the standard tests of a regular vehicle: crash, cold weather, durability and road handling tests. It's been tested at length on European cobblestone streets that would make anyone's back hurt, and in snowy conditions in Sweden. Even in cold weather, the car's heating, ventilating and air conditioning system keeps a constant temperature inside the battery pack so it performs in inclement weather.

Still, engineers in the audience were concerned about how fast and far it could go at high speeds or while taking it up to Lake Tahoe (approximately 200 miles northeast of San Francisco), given that its battery range is between 200 to 250 miles and driving at a constant high speed can drain the battery length.

"It's designed as a sports car. Take it out, impress your friends and go out to dinner," Bourn said. Considering the crowd of lead foots, he added: "You guys aren't going to get 200 miles at all."

Tesla announced in recent months plans to open a factory in Albuquerque, N.M., to produce its next-generation car, a five-seat, electric-powered sedan code-named WhiteStar. That car will roll out in late 2009, according to a press representative from Tesla. It will start at $50,000 and sell for as much as $70,000 for the sport version.

The event was held here at TechShop, an open workshop that lets members, for $100 a month or $30 a day, have access to all manner of industrial tools like laser cutters, brake presses or a 3D printer. TechShop opened in October with little to no press and has so far attracted 120 members who have made things like robots, custom skateboards, espresso machines and car parts. The girl working the front desk etched her Mac laptop in flowers using one of the workshop's two laser printers.

"I've been a member since November, and it's fun," said one of the attendees.

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28 comments

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LiON batteries
Hopefully the Tesla isn't using Sony batteries.
Posted by kpedraja (1 comment )
Reply Link Flag
LiOn batteries
Yeah, lets hope it uses batteries from a brand that, when things go wrong, doesn't assume the responsability.
Posted by Fil0403 (1303 comments )
Link Flag
Hopefully...
... the price comes down some more, so that more people can own
some of this technology.
Posted by rfelgueiras (189 comments )
Reply Link Flag
Unreliable Tesla
I hope their car is more reliable than the folks who are running the Tesla company. They avoid all talk of battery costs, which for an electric car, is the same as fule costs. That battery pack costs between $21,000 and $30,000 and gets a paltry 100,000 miles, making the costs per mile a staggeringly high 25 cents just for the batteries, not counting the electricity. That's equivalent, folks, to $7 to $9 per gallon gasoline. Tesla claims the car cost "a few pennies per mile" to operate. Actually, the figure is between 20 and 30 pennies per mile.
I also note that Tesla officials originally claimed that the roadster would travel 250 miles on a single charge, no exceptions,. Well, eveyone knows that an electric's mileage depends upon terrain, weather, use of A/C, etc. The EPA recently tested
the roadster and gave it a 200 mile range rating,
which is 20% less than that originaly claimed by the company. Now I see the company is claiming 200 to 250 miles. The 250 mile figure is out of line with the official mileage test results. Tesla is playing games again.
Posted by theBike45 (90 comments )
Reply Link Flag
Get a clue.
If things like cost per mile or the cost of the battery pack are a concern for you, The Tesla is not your car.

The Tesla is targeted to the market segment that considers a $100,000 purchase near trivial. If a Tesla is much more than an impulse buy for you, you should get a Honda Civic (Great car, with just a bit of work, it has great performance).
Posted by ralfthedog (1589 comments )
Link Flag
give a chance
hey they cars are not even out yet - lets give it a chance before
we condemn it.

also note:

1) they warrant the batteries for 100k, real world they may go
longer.
2) tesla made a public statement, blog entry a while back from
the founder, that they had to back off on the 250 mile range.
The car needed to gain weight for stiffness and safety, things
like that. I am sure if you are on the list of purchasers, you can
get your money back, since there is still a long waitinglist.

and if you dont like tesla, why not just buy from one of the other
all electric car companies, like the cars that go 40 miles and 25
miles per hour, look like a giant blob - those are great.
Posted by rosnow (19 comments )
Link Flag
Get a blond.
I give this car a chick magnet factor of 8.5
Posted by ralfthedog (1589 comments )
Link Flag
New LiON Technology Goes Further
Current technology Lithium Ion batteries are only good for about 500-750 charge cycles before they start loosing a significant fraction of their charge capacity. At 200 miles range, Tesla is sticking with the 500 charges number (200*500=100000). So they are being conservative and still get about 10 years life (assuming play car miles per year).

And if you want to make your comparison fair, you need to throw in the cost of a new Porche 911 motor, which you would probably need after 100k miles in that car as well.

And all of this assumes that they don't quickly make the switch to AltairNano batteries which with new anode material that gets more on the order of 5000 charge cycles, or about 1 *million* miles, not to mention demonstrated charging times of 10 minutes with an external charger (see their website and Phoenix Motorcars for a vehicle driving around with those batteries today).

So your comments seem a little prematurely bitter.
Posted by jlfelder (61 comments )
Link Flag
New LiON Technology Goes Further
Current technology Lithium Ion batteries are only good for about 500-750 charge cycles before they start loosing a significant fraction of their charge capacity. At 200 miles range, Tesla is sticking with the 500 charges number (200*500=100000). So they are being conservative and still get about 10 years life (assuming play car miles per year).

And if you want to make your comparison fair, you need to throw in the cost of a new Porche 911 motor, which you would probably need after 100k miles in that car as well.

And all of this assumes that they don't quickly make the switch to AltairNano batteries which with new anode material that gets more on the order of 5000 charge cycles, or about 1 *million* miles, not to mention demonstrated charging times of 10 minutes with an external charger (see their website and Phoenix Motorcars for a vehicle driving around with those batteries today).

So your comments seem a little prematurely bitter.
Posted by jlfelder (61 comments )
Link Flag
Re: Unreliable Tesla
Have to take issue with your numbers here. A Porsche gets 20mpg avg, tops. Also you need to figure in the cost of motor maintenance: oil & filters, spark plugs, air filter, coolant, everything that just doesn't exist on an EV. Also maintenance on brakes will be much lower since it uses regen braking.
Posted by markwil (4 comments )
Link Flag
The Green Machine
If you want to buy a car that is environment friendly, then go ahead buy a diesel vehicle and make it run on BioDiesel. It is less expensive to the owner of vehicle with just the least adjustments. Even though it is a solution that is far from perfect, it is the one with least transition and costs attached.

Hybrids (esp. the ones that give good mileage) are good option.

I forgot to mention, if you live in a region where there is lot of sun, dont shy away from that Motor Bike.
Posted by YankeePoodle (785 comments )
Reply Link Flag
RE: The Green Machine
Don't know where you get that, a diesel still produces pollutants and CO2. Not very environmentally friendly. I does cut our dependence on the middle east though.
Posted by markwil (4 comments )
Link Flag
If only...
The design was open source. Oh, well. Once OSH catches up to OSS, we'll have a better one in no time.
Posted by ethana2 (348 comments )
Reply Link Flag
Promises, Only Promises
Another electric car that is supposed to come out
in the future. Fishing for investment capital?
News.cbsi.com usual article.
Posted by bobbydi (51 comments )
Reply Link Flag
RE: Promises, Only Promises
First cars will be delivered in September.
Posted by markwil (4 comments )
Link Flag
You guys never change
I've owned an electric vehicle for 5 years now with no problem at all. I find it to be fun to sneak up on people and scare them. I have not hit anyone with my vehicle yet and the braking is super.
Posted by Richie (21 comments )
Reply Link Flag
electric car...
Besides price, performance is the only thing keeping us from going to an electric car. As a soldier, I'd love to be able to tell all those OPEC countries to go play in their sandbox and kill each other. Without needing their oil, we really wouldn't care. But I also would want a car that would perform. Many of my peers have sports cars (I have a Mustang GT.) I couldn't give up my performance car for an Ed Begley style electric car. I'd need something with power. So would many Americans.
Posted by pjamese3 (44 comments )
Reply Link Flag
Why do you need excess power?
Compensating for something?

It doesn't matter if your car takes 5 seconds or 15 seconds to hit 70, it is not like you are racing, or can ever go much faster then 70-75 without risk of a ticket. So what are you gaining? I know, Americans were told that you need powerful cars and like good lemmings you bought into it.

This irrational "need" for power by Americans is odd.
Posted by MSSlayer (1074 comments )
Link Flag
Did you even check out the Tesla?
Is 0 - 60 mph in 3.9 seconds enough performance for you! Performance isn't the problem with electrical cars. What has held them back on a pure performance front before now is the batteries, namely their power density. Lead-acid and NiMH just can't dump a lot of Watts per Kg.

But Lithium Ion has not only better energy density, but also better power density. So for a given size battery pack, you can accelerate faster and go further. So with current generation LiON batteries your Mustang GT looks anemic. With the next generation batteris like the A123 and AltairNano with 2 to 3 times the power density, old technologies like internal combustion engines will looks positively geriatric.

As for price, price is just volume. Low production rate sports cars with cutting edge tech in them already run $100K. But back off the bleeding edge a little, and up the volume level, I don't see why $25-$30K electric Miata isn't possible.

But new manufactures have to start small, and Tesla went the right path in coming out with a car that appeals to people willing to drop serious cash on a play car. Success here can be leveraged to do the next generation (already on the books) at a lower price point, and then a third gen at even lower prices, and so on.
Posted by jlfelder (61 comments )
Link Flag
Did you even check out the Tesla?
Is 0 - 60 mph in 3.9 seconds enough performance for you! Performance isn't the problem with electrical cars. What has held them back on a pure performance front before now is the batteries, namely their power density. Lead-acid and NiMH just can't dump a lot of Watts per Kg.

But Lithium Ion has not only better energy density, but also better power density. So for a given size battery pack, you can accelerate faster and go further. So with current generation LiON batteries your Mustang GT looks anemic. With the next generation batteris like the A123 and AltairNano with 2 to 3 times the power density, old technologies like internal combustion engines will looks positively geriatric.

As for price, price is just volume. Low production rate sports cars with cutting edge tech in them already run $100K. But back off the bleeding edge a little, and up the volume level, I don't see why $25-$30K electric Miata isn't possible.

But new manufactures have to start small, and Tesla went the right path in coming out with a car that appeals to people willing to drop serious cash on a play car. Success here can be leveraged to do the next generation (already on the books) at a lower price point, and then a third gen at even lower prices, and so on.
Posted by jlfelder (61 comments )
Link Flag
Back up a step
Electricity from thin air!! Not.

Where do you think most of the electricity that charges your car and heats your toaster(s) comes from. Mostly oil- and coal-fired generating stations, plus some natural gas. Also, about 1/6 of US oil comes from the ME; the real problem with ME oil is that, like poppies, it funds those who'd like to exsanguinate the West with as dullish knife to the throat - on Al Jezeera, of course.

So work on getting secure non-hydrocarbon generating capacity, such as microwaved power from lunar solar farms.
Posted by BrianFH (54 comments )
Link Flag
Performance.
I totally agree with you,I love performance! I drive a Tahoe police package. But a 0 - 60 in 4 seconds is better than a Mustang could come close to. And a Mustang isn't really a performance car to me. a BMW M5 (heavy ass sedan) will blow its doors off. Yes, it costs more. but like you said. More performance.

RiversK
Posted by Speakerboxx (2 comments )
Link Flag
What about the costs to recharge the batteries?
The article and comments don't address the issue of recharging the batteries. How are the batteries recharged? How long does it take to recharge? How much does it cost to recharge? Doesn't a lot of the electricity used for recharging come from coal-fired plants which produce CO2? If recharging is taken into consideration the car might not be as green as it first seems.
Posted by dougwong55 (1 comment )
Reply Link Flag
Indeed.
In general, producing power in a central location to feed many end-users, is cheaper, cleaner and more efficient than producing power on an individual basis, so there is a moderate gain there. Coal, petroluem, waste oil, garbage, wood; *anything* we burn releases CO2. Coal just happens to be a lot dirtier than some of the other things that we burn.
Posted by timinraymond (6 comments )
Link Flag
RE: What about the costs to recharge the batteries?
The battery takes several hours to recharge depending on how depleted it is. But since the range is enough for a daily driver you just plug it in at night.

California's power mix includes around 40% non-CO2 producing sources:
<a class="jive-link-external" href="http://www.teslamotors.com/efficiency/environmental_benefits.php" target="_newWindow">http://www.teslamotors.com/efficiency/environmental_benefits.php</a>
Posted by markwil (4 comments )
Link Flag
secret media(aka big brother) will try to make it seem unreliable
If you cant figure out how massive effect on the world economy this car or any car that is oil free, will have, you should go back to highschool. This car is perfectly reliable, easy to work on, and has "guts" to back it up. NO MATTER WHAT, ANYONE ELSE SAYS, THIS CAR IS GREAT. dont believe everyone elses lies.
Posted by Zupek (85 comments )
Reply Link Flag
 

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