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Tesla Model S Electric Car
Tesla Motors ^ | 27 Mar 09 | Tesla Motors

Posted on 03/27/2009 2:28:12 PM PDT by NavVet

click here to read article


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To: normanpubbie

(besides the fact the company is a corporate mess...)

my understanding is that the way they were able to increase the battery capacity is via a cooling box for the battery.


61 posted on 03/27/2009 6:18:10 PM PDT by longtermmemmory (VOTE! http://www.senate.gov and http://www.house.gov)
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To: normanpubbie

Can’t we derive some data from the coupes they already have on the road?


62 posted on 03/27/2009 6:19:20 PM PDT by nufsed (Release the birth certificate, passport and school records.)
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To: DB

If it IS vaporware, then they should fail just like any software company.

But at least Tesla had a backup list of buyers for their products. Of course, outside of California that demand drops off dramatically. If they can produce something which actually works (like Toyota and Honda did with the hybrids) then they will succeed and deserve to succeed.

But in CA the chance of getting public subsidy is practically a birthright when it comes to anything on the left. After the first year, anything which can’t survive with private financing should be gone. Otherwise, we are all living in our own private Iowa (the ethanol boondoggle state).


63 posted on 03/27/2009 6:19:43 PM PDT by bpjam (Tell your Rep/Senator to Google: Marjorie Mezvinsky. Yes, it IS a threat.)
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To: raisetheroof
248hp x 746 watts/hp

This is the most relevant information you provided. An electric motor requires 746 watts of electricity to achieve one horsepower.

The exact definition of one horsepower is 33,000 lb.ft./minute. Put another way, if you were to lift 33,000 pounds one foot over a period of one minute, you would have been working at the rate of one horsepower. In this case, you'd have expended one horsepower-minute of energy.

Electrical power is the rate at which electrical energy is converted to another form, such as motion, heat, or an electromagnetic field. The common symbol for power is the uppercase letter P. The standard unit is the watt, symbolized by W. In utility circuits, the kilowatt (kW) is often specified instead; 1 kW = 1000 W.

In DC (direct-current) and low-frequency AC (alternating current) electrical circuits and systems, power is the product of the current and the voltage.

Now with that in mind 746 watts of power from 245 Volts DC (typical 34 7.2 volts battery modules connected in series) would require 3.08 Amps of continuous current. Therefore, 248 horsepower would require 185,008 Watts of power. 185,008 Watts of power would require 755.13 amps of 245 volts DC current.

In the American Wire Gauge (AWG) standards, a six wire gage decrease gives a doubling of the wire diameter. Note: The lower the gages number the larger the diameter. Interpolating the wire size indicates that a wire capable with carrying 760 amps would have to be almost 1 inch in diameter.

A couple of cogent questions to ask would be :

How many miles can the car travel at a constant 65 MPH before the speed drops below 65 MPH?

How long will it take to charge the battery from a standard 120 volt AC 20 amp outlet to the capacity that would allow the number of miles in the first question?

How many amps of 120 volts AC are required to fully re-charge the battery in one hour?

Recall Bernie Madoff before sending your down payment.

64 posted on 03/27/2009 6:23:49 PM PDT by MosesKnows
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To: NormsRevenge

I found the picture in my head rather humerous, I’m glad someone else enjoyed it.


65 posted on 03/27/2009 8:11:29 PM PDT by dangerdoc (dangerdoc (not actually dangerous any more))
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To: longtermmemmory; nufsed
I could not find a technical review for any of the Teslas. But I did find one video and a recent article, both of which provide additional information. If you are interested in actual numbers, check out this video:

http://www.youtube.com/watch?v=W43Q90vMS7k

and

the recent Mercury News article

According to the video, the battery pack contains 6,831 lithium-ion cells connected in series-parallel for an output voltage of 366 VDC. Assuming 100 percent efficiency in the drive motors, current used at the rated 248 horsepower would be 505 amps. Of course this 248 HP would occur only during rapid acceleration and is thus of short duration.

The video also says that each individual cell is cooled by circulating antifreeze and that the heat generated is dissipated by a radiator and two fans, presumably during both acceleration and charging. As the video pointed out, you do not want to overheat high-capacity batteries like the Li-ion and Ni-metal-hydride units.

Will the all-electrics beat the internal-combustion vehicles or the hybrids? Probably not because a gallon of gasoline stores vastly more energy than a gallon of battery.

Let's do some more numbers.
A gallon of gasoline weighs 6.175 pounds and produces 32 KW-hr of energy during combustion. Figure 30 percent gasoline engine-drivetrain efficiency and you are talking 10 KW-hr per gallon. By comparison, the standard Tesla battery pack weighs 1200 pounds and produces 42 KW-hr of energy. Today a gallon of unleaded costs just under $2.00 here. Figure it would take 6 gallons to go 160 miles in a gasoline-powered car for a rough total of $12.00. Electricity at 10 cents per KW-hr would run just over $4.00 for the same distance. Let's drive both cars 16,000 miles. That would be $1200 for the gasoline vehicle and $400 for the all-electric. We saved $800 by driving the all-electric but the battery pack cost is many times that amount. If we could cut the battery pack weight by 90 percent and the cost by 90 percent the all-electric would be quite competitive. But don't hold your breath waiting for that to happen.
66 posted on 03/27/2009 9:18:54 PM PDT by normanpubbie
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To: normanpubbie

The article you cite, doesn’t seem to catch the problems you describe. Although not a direct refutation, you should consider that the Tesla Roadster has been in production for over a year and the technical specs have proven to be fairly accurate, although the 0-60 time for the Roadster is under four seconds.


67 posted on 03/28/2009 2:43:17 AM PDT by NavVet ( If you don't defend Conservatism in the Primaries, you won't have it to defend in November)
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To: DB

Thanks for the link.


68 posted on 03/28/2009 10:36:48 AM PDT by GOPJ (Global Warming Hoax - Sucker Science In Action)
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