Weight gain from prototype to production ready seems “par for the course” for most new models. I read story after story in car magazines about lightweight prototypes that put on the pounds before going into production. The original specs met with so much excitement that it must hurt to go from the “honeymoon” phase to making public apologies for not meeting the projections.

www.mercurynews.com/ci_5695203
“” Tesla Motors modifies claim of 250 mile range “”

Still, if I had put down a deposit, it would have been disappointing news as light weight is so crucial in a small sports car.

On the other hand, I was concerned at the look of the stereo in EP1, so it is good to hear that you are beefing up the audio system! Personally, the quality of the stereo in a sports car is very important. You need the serious road tunes to have the real fun.

I had hoped that you would have been able to actually get better battery technology than originally tried in the prototype, as Li-Ion batteries seem to be improving so rapidly. It is unfortunate that you weren’t able to get an improved battery to keep the range even with the extra weight.

I’m sure everyone at Tesla is nervous about this announcement, especially considering one particular member of the media (who I can’t currently remember) who has been particularly critical of your early specifications. You can rest assured your audience is still going to love and buy your fantastic vehicle. (And darnit, I still want to invest! Tell me what I need to do!)

Thanks for your clear and honest update!
Kevmo

Anything over 100 miles per charge is more than sufficient for my needs for most purposes, so over 200 miles on a charge is gravy to me.

Compelling information, nice to see that its becoming a real functional car which will silence the critics and skeptics. Thank You for the update.

Are you considering a Canadian presence in the near future?

I agree with you that the premise is still intact. Any range above 150 miles (that is still less than the 600 mile road trip range) is merely added convenience for unusual circumstances. Very few drive more than that in a day.

That’s why this announcement is no big deal–the car has lost no functionality that anyone needed from it anyway. If you were announcing that you were going from roadtrip range to less, that would be a big deal, but this? Nah. Ya’ll’re still amazing.

PS: Please lighten the background of your comment box. The black insertion point is hard to see against the dark gray.

“as I rocketed around the curves of Skyline Boulevard”

You did not tell me that part of the story when you got home last night!

Martin, thanks for being so open about the progress with the Roadster. I actually see all of this as a positive more than a negative. More weight is always bad, but the fact that you are making these changes is a testament to the amount of testing your team is doing and the thoroughness of that testing. In spite of the reduction in range, the Roadster will undoubtedly be a more robust car, and a great first effort. I’m sure the lessons learned from this program will be applied to WhiteStar to make that one even better.

The car that is built has a longer driving range than the one that isn’t. Don’t let the halibuts get you down.

My 1985 BMW K100RT (touring motorcycle) only gets 100 miles on a tank, 130 if I over-fill and ride slowly. It’s never been a problem for me.

I’m a little surprised that the extra weight affects the range so dramatically — some 20 percent — while acceleration remains unchanged. I would have thought the opposite, that the acceleration would be much lower, but the range only a little reduced. To be sure, Martin says they’ve improved the VP’s drive train over the EP, but somehow I thought acceleration was (basically) a function of weight versus thrust. With “several hundred pounds” (or is it a “couple hundred pounds”?) of added weight and ostensibly little added thrust, it would seem the motor has much more inertia to overcome when accelerating. Range, by contrast, seems largely a function of wind resistance, as the weight of the car adds relatively little drag once at speed. Then again, perhaps the EPA cycle has a lot of starts and stops…

I see that the front page still lists the efficiency as “135 mpg equivalent”. If this is still correct, it also implies that
a) the drive train is not only more powerful, it’s also more efficient because it’s apparently accelerating more mass using the same energy
b) the ESS storage capacity may have gone down 20% from around 56kWh (250mi * 213Wh/mi + safety margin) to 45kWh (200mi * 213Wh/mi + safety margin)
c) these new cells can really take abuse - assuming the 80% max power motor efficiency number in the FAQ, then the 185 kW motor is pulling 231 kW - more than 5C - during a “hole shot” - which likely only lasts for 10 seconds or so until the car hits the speed limiter. How quickly can the Roadster repeatedly run 1/4 mile maximum sprints? Would the safeties kick in to protect the ESS? Will the 130mph limiter impact 1/4 mile times?

I would have thought that the newer batteries would be more reliable and tollerent to abuse. New advances include design changes to reduce chances of fire and lower internal resistance. A123 is now claiming 7000 cycles have been achieved. Lower resistance means that they do not heat up as much and are more efficient. Having said that there are other negatives, newer technology is more expensive and untried. These would be valid reasons for Tesla to stay with older technology. I take it that this choice of batteries has not changed, that is Tesla has not chosen a lower power battery (which would reduce range) to gain reliability than in the original prototypes.

I agree with Brent on his statement that the extra weight should affect acceleration more than distance. One of the great advantages of the electric drive is regeneration, If it takes more energy to accelerate because the increased mass creates more momentum, then there should be more energy recovery on braking. The main determinates of milage should be rolling resistance and wind resistance, not mass.

Regenerative braking should produce decelleration almost as strong as acelleration. If memory serves me right, Tesla claims about 86% efficiency. In actual driving conditions, we decellerate mostly by coasting, letting the rolling resistance do most of the braking, this portion is not available for recovery, and only 86% of the remaing energy can be recovered. Even so I challenge the Tesla engineers to refine regenerative braking as a means to extend milage.

I should have read TEG’s link before I made my last post. In it Darryl Siry states that Tesla has “switched to lower capacity lithium-ion batteries”. So they are not as good as the original and may in themselves be the main determinant of lower range rather than the increase in mass.

I was riding into work today thinking about when I’ll be able to get a plug in like the tesla, when I came up with a great option idea to be packaged with your cars. I would like to see a recharging “pack” for the garage or home of the car that can be charged with alternative energy. For instance, the battery back is utimately what charges the car, and you can charge the pack by, say, solar panels on the roof of the garage. Hence a truly Green car.

Keep up the good work, and let me know when I can get a tesla for about 30k.
-Z

I’ve been reading these blogs for quite some time but only now feel that I have a worthy comment. Thanks to everyone for an interesting discussion.
I am also not a prospective Roadster owner, but could consider a White Star or future vehicle. ( Man, oh man do AI want an electric car!) But it does seem to me that a reduction in range from 250 miles to 200 is significant. Say, a recent trip to pick up a friend at LAX. 180 miles round trip, some additional miles to stop and get something to eat, etc., and we’re just too close for comfort for my taste. I realize that this is way more than an average daily commute but is the roadster really intended for going to work every day? And I know that it isn’t intended for cross country driving, but that 250 mile range seemed to me to be a real minimum for a sports car that you’d want to really drive for a day. Again, there’s no danger of me now not buying a Roadster as I don’t have 100 grand to throw at a car in any case, but if I did, this might just be a deal breaker for me. A real shame, it seems.

It would be interesting to hear more variations on the range, rather than the one (EPA) figure. What about just getting on the highway and driving 65 mph until the juice runs out, without maxing the acceleration at every opportunity. What about just driving around town, sedately in very short hops? (Yes, yes, I know that that isn’t the way people drive exoticars, but it would seem to relate to future products) And it strikes me that electronically trading off performance for range is a great idea in general.

Thanks for these blogs: I am truly impressed by the transparency shown by Tesla.

I have two questions:

Is Tesla planning on submitting any of their models to be considered for the recently accouned Automobile X-Prize? It seems the White star or perhaps third model will definitely get the required 100 mpg equivalent. Considering entering any future models?

Has anyone called to cancel their order due to the shorter range announcement? I hope not.

In my previous post, I neglected to consider the slight decrease in capacity of the Li-Ion cells, so perhaps the MPG equivalent is still higher than 108mpg, but certainly lower than 135mpg given the added weight.

Thanks again,
Eric

I would like to have electrical engineer’s e-mail adress who work at Tesla that I can ask couple of questions why things work as they do. I also would like to know if those engineers have consired other options how to expand the range with internal chargers or with external options in the future models (I would preferably talk with a person with experience with electric motors and charging a batteries)
Thank you…

—-

Editor’s Answer: Why don’t you post your questions in a comment. 

An excellent writeup! After listening to many co-workers complain about their “high mileage” car’s actual performance, seeing a company coming in with a low-ball number is amazing. You’ll never see Toyota say, “Well, the EPA rating is 62 mpg, but no one has ever better than 51″. (or whatever). No, it’s “your mileage will vary” and they blame the funny numbers on the testing method, all the while campaigning against realistic testing.

Tesla has too much at stake to risk using anything other than a proven battery cell. I’m certain once the newer batteries have a track record (say 20-40 million installed), you’ll be back to the 250 miles or higher.

More on battery choice. You Martin, have told us several times that smaller battery packs lead to higher abuse. Instead of having the luxury of reduced peak charge to enhance battery life one must choose to charge closer to the limit to go the same distance. Ultimately if the charge life is 500 cycles and this is 500×250 miles = 125k lifetime distance (before considering battery replacement) and now the charge range is only 200 miles then 500 cycles is only 100k miles. Now you say that these smaller batteries are more abuse tolerant, and the only specification quoted to compare is life cycles, so are these smaller batteries rated at 20% more cycles? What are the actual numbers?, so we can see how much increased lifetime range one gets for the shorter single charge range?

While it is a great point to state that regenerative breaking should nullify much of the negative impact on range this doesn’t take into account how effective the regenerative breaking may be. If there is a capacitor on the car that can suck up a lot of juice generated by regenerative breaking very quickly, then yes, I agree regenerative breaking should be very effective at lessening the impact of the extra weight. However, if the only thing that you have to suck up the power provided by regenerative breaking is the battery, then it will not be nearly as effective. Our standard Li ion batteries just can’t pull in the massive charge quickly created by regenerative breaking and so a lot of it goes to waste.

I know you are still conducting tests on the roadster. This year of 2007 is or I thought was supposed to be the delivery year for the first 100 roadsters. I was just wondering if this is still on schedule and if not what is the expected delivery of these cars to our smoggy and gas filled highways.

Thank You

Any thoughts on lower costs by switching to the “lower capacity”, “more mature” cells? Will they improve profit?

As a future Tesla owner, who lives in Santa Barbara with regular commutes to LA, the range reduction from 250 to 200 miles is very significant for me. I’ve planned all along to get a second charger installed in LA, and now I guess I’ll be using that more often… but what I’d like to see from Tesla (in lieu of repricing, which IMHO is not justified), is some assurance that the Roadster is future-proofed to accommodate higher-capacity battery packs once they’re available, and perhaps Tesla could offer some discount or rebate to current owners on the eventual swap-out. Alternatively, perhaps Tesla could offer current customers the option of the higher-capacity battery pack today, but with a shorter (4-year vs. 5 year) warranty? It would be interesting to see what percentage of the current buyers would choose this option, if it were available.

I can only hope that Tesla will refine their car to greater lengths in order to attempt to achieve the coveted 250 mile range. The GM EV1, when under developement, was having each individual part weighed by the gram to painstakingly take teh car closer and closer to its target.

By the way, is the “EPA-compliant dynamometer” compliant for the new EPA testing, you know, the more realistic testing, or for the older and more unrealistic testing?

# Brian Langlois wrote on April 19th, 2007 at 11:27 am
## Would it be possible to have the controller set up in a way
## to switch from ‘range’ to ‘performance’ similar to a high-low range?

Yes, we need more control knobs, and this has been mentioned before in the earlier blog pages.

www.teslamotors.com/blog2/?p=27
# TEG wrote on September 28th, 2006 at 1:47 pm
## A slider or knob for economy versus performance mode.
## If the Tesla driver wants to maximize range they could change
## the control to provide less aggressive acceleration, lower top speed, and all that.

www.teslamotors.com/blog3/index.php?p=36
# Bill Korea wrote on November 11th, 2006 at 8:46 pm
## how about adding a knob to adjust the maximum amount of regen available?

By the way, I am proud to see that my facorite car company (Tesla!) is being truthful and honest, something that some companies are afraid of. Remember, this is a step forward, not backward, to the reality of production EVs roaming among our roads.

Tals: Thanks for your statement on recharging. I beg to differ, all I have read about Lithium-Ion batteries has suggested that the maximum recharge rate is similar to the maximum discharge rate. If the batteries can supply enough current to drive the car from 0 to 60 in 4 seconds, why can’t they accept enough current to decelerate the car from 60 to (near) 0 in 4 seconds? I think I know the answer, and it has nothing to do with the batteries themselves but the arrangement. You can’t get much regen into a 357 volt load, but if the load was near 0 then it would suck up a lot of power, right? Now this might sound rediculous, but I think not. If you had a massive 294 pole 2 position switch, you could switch all the batteies from series to parallel arrangement. This switch would only activate changing from acceleration to deceleration and back while all the IGBTs were OFF. In this way the load voltage for regenerative brakeing would be 3.6 volts. If the batteries were also charged in the low voltage position, charge balancing would not be a problem. Since the switch does not have to change under load, the physical size of the contacts could be manageable. The other benifit of this arrangement is that the charge current into each battery would actually be quite low at max current (500 amps)/6831 batteries = 0.8 amps. The reason I suggest a mechanical switch instead of semiconductor is that there must be neglible voltage loss across 98 switches.

Thankyou Mark and Brent for your links about EPA dyno testing, but these do not address the question I have, which if far more technical. I am not concerned with trying to match a standardized driving pattern to evrerybody’s personal patten, I don’t believe that is possible. I am content with a standardised pattern evien if unrealistic , as long as comparison of one auto to another is valid. My technical question is how is the mass of the vehicle simulated? For that matter how are the wind and rolling resistances simulated? And does the dyno provide driving power into the wheels during brakeing so the regen system can re-charge the batteries in the normal way. My point is a dynometer by definition only consumes power, does not deliver power.

Joshua: I and others have discussed the automotive X-Prize on the “Feel” blog. in short, the Roadster does not qualify because the production is projected at 1000/year and the X-Prize requires a projection of >10,000/year. The WhiteStar will qualify as production is projected to be 15,000 /year. I am going to repeat an unanswered question; Is Tesla disqualified because Elon Musk is on the X-Prize board?

Brian Langlois: The short answer is No. The controller and motor are designed to operate at highest possible efficiencies at all times. In a electric car you do not sacrifice performance for range. This could be accomplished in software by limiting the maximum speed of the car to increase range, but this is just the same as not putting your foot down as much.

Petri Haikonen: There is an amazing amount of information about this car on this website. Check White Paper, FAQs, and many previous blog pages, especially in this and “Touch” blogs. Chances are your questions have already been answered. There have been many suggestions of on-board generators and other hybrid variations. This has been addressed best in “Balance” if memory serves me right. In any case I agree with Tesla’s philosophy of keeping the car a “pure” electric because of reduced complexity. Leave the hybrids to others.

I’d love to know if dual-sport (enduro) motorbikes could be designed using your technology!!! Dual-sport bikes are so much lighter and versatile than other bikes, so wouldn’t they be easier to design? Just an idea (I got dibs on one if you guys run with this!

Hello,

is it possible to get a high res picture (1280 x 1024) of the “VP1 in San Francisco” above?

Regards Christian

—-

Editor’s Answer: We are about to add some pictures, screensavers, videos etc to the site. They should go up in a couple of weeks. 

Please let us know the details for the Tesla visit to Chicago. Can’t wait…

Regarding the range of the vehicle, I think the range is great for most daily uses. However for longer trips I had a thought yesterday walking by the gas station (that also sold propane tanks — the exchange type for gas grills). Perhaps service stations could convert to large charging stations which would sell (or exchange) the ESS already precharged. Simply pull in and exchange your ESS. I am sure the roadster is not designed for easy access to the ESS, but perhaps future models could take this into account. When I am on a long plane trip, I usually bring a spare laptop battery. Same principle… Just swap out the ESS and your good for another 200 miles or so. (Of course the service stations would need to include solar panels on the roof as well) Also perhaps it could be faster to charge the ESS with specialized equipment at the charging station, and reduce some potential “at home” charging dangers…

My point was not, of course, that I live a certain distance from LAX. That simply seemed like a reasonable trip length for a car such as a Tesla Roadster. Sure I’d want to pick up my friend (and his one bag) in such a ride! My gut feeling is, though, that 250 miles was a sort of minimum range that I’d want from a car that was fun to drive, and that one might want to take out for the day. Commute, sure, but there are way cheaper and more energy efficient ways for most of us to commute to work. 200 miles means a few hours of driving and then back home overnight. Can’t stray more than 2 hours from home. Once again, there’s no danger of my NOT buying a Roadster now, but it does strike me that range would be a critical number for me were I in the market (and will be when I am in the market) and 250 seemed like about as low as I’d want to go.
One man’s calculus…

David_42 - Only “one roadster”? a123 has been manufacturing 10s of thousands of cells for use in Black &Decker’s Dewalt power tools. They are not putting their cells together by hand, rather they are being manufactured in two wholly owned battery plants in China with overflow being manufactured by China BAK. To top that off, they have raised over $100 Million in capital from sources like Sequoia Capital, Procter & Gamble, General Electric, Qualcomm, the CIA and many others. On top of that they have a $15 Million contract with USABC. A123 is far from vaporware… The question is just how expensive are they. As to its benefits to the Roadster, the additional power is the gravy, the real benefits are in the stable construction (which will allow for an air cooled ESS without special heating for the winter and cooling for the summer), and the increased life for the car. Bear in mind, you need a working battery regardless of whether you keep the car through 100,000 miles or you sell it. If you intend to throw away the car after 100,000 miles it makes the cost of ownership VERY expensive.

My 1985 BMW K100RT (touring motorcycle) only gets 100 miles on a tank, 130 if I over-fill and ride slowly. It’s never been a problem for me.

Surely you’re joking? I owned a 1985 K100RT for 120,000 km (30,000 when I got it, 150,000 when I sold it) and it went much further than that. I don’t remember the exact range now (it’s been a dozen years since I sold it), but I know I got about 45 mpg (UK) from it and on a 900 km trip I regularly made on twisty mountainous NZ backroads cruising at around 140 km/h (87 mph) I had to refill twice, making the safe range at least 300 km (185 miles).

I’ve had a 1995 R1100RT for the last dozen years. It does 300 miles at 60 mpg if I more or less stick to the speed limit, or 250 miles if I cane it.

There’s a new company -www.climos.com -that will work on ways to remove co2 from atmosphere. They don’t say how, but another site said one thing they were doing was looking into making huge ocean phytoplankton blooms to remove co2.

Some comments:

Why not consider a different logic and bypass refuelling all together?

Personally the longest I have ever driven in a day was 16 Hours. I think that is about the maximum any sane human being would want to be in any car/truck as a driver let alone a passenger. So do the math 16 Hours X 55 Miles per hour avg. = 880 miles. That is the goal , period. That would require Mr. Eberhard and his merry bunch of engineers to increase range 440%. I will leave that to the engineers to determine the specific power density that would require. However I am confident this is possible.

Where is it written that you have to trade in the car after 5 years?

Remember, There is nothing saying you can replace the entire battery pack when the thing is exhausted after 100k miles.
By the time the battery needs to be replaced I am willing to bet it will be cheaper and extend your range even further than the original 1st generation battery pack. I believe the batteries are set up like blade servers allowing them to be easily removed and replaced. Instead of trading your Roadster in .. UPGRADE. New battery pack and some firmware and whammo! At least another 100k miles in a car that can still do 0-60 in 4 seconds with extended range for the 25k and a day to replace the batteries.

My plan is to buy the white star and drive for 5 years. Replace the batteries and repeat until I get 500,000 miles out of the beast.
Even if the battery tech did not get cheaper it works out to the following roughly. 50k for the white star. 25k for each battery replacement. 25 Years of driving equalling 500,000 miles for $150,000 .
Where do I sign up?

david_42 wrote on April 20th, 2007 at 6:45 am:
>who here (besides me) has driven a car more than 100,000 miles?

My 1996 Nissan Altima GXE, which I bought new in 1996, has 195,000 miles on the odomoter. When I bought it, I expected to have it for 10 years. It should easily be good for another 5.

I really don’t think 100,000 miles is all that remarkable any more. Do you know about Saab’s 1,000,000 mile offer: www.saabusa.com/saabjsp/about/pr_061218.jsp

I am really interested in this car! It’s the best idea that I’ve seen since te microwave oven, and that’s saying something. I have a feeling that this company is really going to take off and become the nexdt Mercedes-Benz. With that being said, when are you planning to sell open stocks? Please send an e-mail my way when you do, because I’ll be buying plenty of shares .

I wish you the best of luck and keep up with this awesome production vehicle! Also, if you were to bring a demo car down to Phoenix, AZ, that would be great too .

> Martin Eberhard wrote on April 19th, 2007 at 7:15 pm
> Regarding the 135 mpg equivalent:

Thanks for the clarification Martin! It’s great to see the Tesla still has a MPG number about equal to it’s top speed

I was disappointed to hear about the decease in range from 250 to 200 miles. The first thing I would do is to place the new parts on a diet and see how much weight can be shaved off without reducing the strength of the parts. This is how races are won on the race track. Second, I would consider reducing the weight of the battery pack needed by intergrading it for use with fuel cell technolgy. For those of you who have never seen a zinc air fuel cell see www.poweraircorp.com/technolgy/. While it looks like a battery it is actually a self-contined fuel cell the size of a battery. As you can see if placed in an electric vehicle you have what amounts to a traveling wall plug for your EV. Thus, if your battery system ever fails this is what can get you home.

Fuel cells are somewhat like ICE’s in that their “run time” is a function of the size of their fuel tank so they must be designed for the purpose for which they are used. It would of course make more sense to use the fuel cell with the battery system to recharge it because once the fuel cell is turned on it keeps running until it runs out of fuel. Therefore, it makes more sense to use it to continuously recharge the batteries as it is being used to take full advantage of it. Thus, it can be used as a range extender like the generator on the Volt. The volt uses it’s generator to reduce the size of the battery pack to 400 lbs. While you would have to use a larger fuel cell than the one shown, the idea behind it is simple. The fuel cell would recharge the battery and you would ordinary not use the grid to do so. The weight of the battery would be matched against the fuel cells ability to recharge it. For exaple, a 200 lb fuel cell to recharge a 400 lb battery. If this worked out and this is only a guess that such a system would be self suficient for about a week before it would need to be maintained and it’s zinc fuel supply would need replaced, which the driver could do at home in about 15 mins.

Let me give you an example, of the advantage of a fuel cell powered vehicle. They now have fuel cells for electric bicycles. Normally an electric bike is good for 20 miles there and back and it must then be recharged and it takes all night to do so. What the fuel cells does then is give the bike rider “ultra-long range” as it provides up to more than a 200km range and will go 7 -10 days per refuel without the need to worry about recharging as it has fast refuel that takes only minutes. To give an overview of wthat fuel cells can provide lets compair a lead-acid back up a power pack with 8 hours of backup power. It would take up 65″ of space and weigh 2,800 lbs while a fuel cell would requie only 20″ of space and weigh only 300 lbs. The technolgy is here why don’t we start using it.

To Eric :

Changing weight from 2500 lbs to 2700 lbs should proportionally increase just rolling resistance component by 8%. For EPA testing conditions Tesla roadster should have rolling resistance approximately half of total resistance. So I would guess that added weight managed just ~4% range degradation. By itself it would reduce 250 miles to ~240 miles. So because range reduction is claimed to come up to 20% major range reduction should come from battery energy capacity reduction and most important from the fact that Tesla Motors business people start uncovering some hidden overpromise of engineering team this time and become very conservative to avoid later legal problems with customers. Such overpromises are very typical in any truly new design like EV.
The sole fact that Martin become talking this way is a sure sign of his engineering team finally coming through real product integration, testing etc and truth starts coming out.

If they hold this line just with that only announced range reduction to 200 miles I would say this is the very great engineering team.

My more typical expectation would be that they would also loose ESS lifetime expectation before replacement way under 100000 miles and would get fairly fast range degradation with mileage. In summer we will also know did they hold 4 sec line for 0 to 60 mph or shifted to somewhat like 4.1 sec. In general I think they would be able to hold the line for acceleration and car agility but would have to reduce even further claims for everything related to single charge range and ESS total range lifetime before replacement. I think later customers would also discover that highway range is likely to be closer to 150 miles.

But even if all that happen but Tesla Motors will REALLY deliver over 300 EV roadsters to actual use of customers and they would sirvive use for at least a year without much problems I think later it will become a milestone in technology history.
It takes best sort of human passion and most dedicated love to make any technical thing with such novelty as Tesla roadster to real market as demanding as U.S. Such things deserve to be legends and they become legends.

In doing some research I found Tesla Motors. I was turned and changed my “dream car” to a Tesla. If you happen to visit Kansas City, Missouri, let me know. I’m dying to get my hands on one and I would love to witness the mystique behind it all. (Unfortunately I’m a little far out of the range to have a service station near me.) Keep up the great design and engineering. Maybe someday I can say I’m proud to be one of those thinking minds in the company too. *nudge nudge*

Increíble, me parece el mejor carro eléctrico hasta ahora. Es lo máximo. Los felicito.

In response to Stuart Koford wrote on April 21st, 2007 at 6:34 am about the issue of spinning bearings:

Why can’t the bearings be keyed? Why can’t the contact surfaces between the bearing and the housing be non-cylindrical? Is it a manufacturing or cost issue?

How about a 2 seat hatchback? You know so you can carry some stuff! And how about designing in a solar charging system? Good artists could make them eye appealing.

Headline: “US gas prices up 8 cents in two weeks, 69 cents on year”
( www.mercurynews.com/news/ci_5728005 )

Headline: “Study: ‘Peak Oil’ Will Be Reached by 2018”
(www.foxnews.com/story/0,2933,266764,00.html )

Headline: “Earth Day at the electric car races”
(www.registerguard.com/news/2007/04/22/c1.cr.earthday.0422.p1.php?section=cityregion )

There was a trend that became a truth that became a future. Some will see it as the end of the ‘Oil Age’ while others will view it as liberation from the same. Either way though, it’s coming and those whose vision extends beyond the Vaseline horizon will be in the driver’s seat once we get there.

Biofuels, sand shale, hydrogen and solar will all have a place in the new reality but regardless of that, our cars will be powered with electricity. The internal combustion engine will soon become an anachronism like the coal burning steam engines that were the glory of the railroads for generations.

If Tesla Motors can migrate their successes with the high end lines into an equally successful and affordable family sedan, the name Tesla will supplant that of Ford and Chevy as the national icon for mass mobility and American ingenuity.

God speed.

…

“So do the math 16 Hours X 55 Miles per hour avg. = 880 miles. ”

You are basing your math on the stupidly ridiculous slow speed limit that bogs down our highways in many parts of the country. Bear in mind that most long trips will get out of the urban “revenue enhancement zones” with the 55mph speed limit and in several western states 75mph is the limit. That puts you at 1200 miles for your estimate.

How much efficiency is lost at 55mph boggles the mind, pure bull-halibut for the fuel savings, my truck gets 8-10 mpg at 55mph, but gets 12mpg between 70-85, and 14mpg at 95-100mph. Yes, I’ve verified this, 2500 rpms is its bottom power band, and in top gear that is 90mph on that vehicle, the increased power gain is more than the wind and roll drag. I’ve personally done Los Angeles to Colorado Springs in 12.5 hours, though the speed avg for that trip is only legally attainable in Montana (100mph). That was a fuel saving trip where I did attain the 14mpg from the V10 motor.

It also shows the point that speed limits are most often BS. Its legal in Montana to do 100mph, safely and efficiently done in many modern makes of car. Same road type & conditions - yet crossing a state line makes it unsafe? Halibut.

Tals: I kinda goofed on my description of the massive series-parallel switch for the Tesla batteries. I figured out that it would require 294 contacts minimum, not switches. Upon review I think it would require 196 double throw switches, arranged as 98 pairs. Since the series arrangement requires each connection to carry full current and each pair could use 1 contact from each switch, in parallel with each other, for the series connection and in the other position, one contact each for connection to power and ground bus. This way the switches only have to be designed to carry 1/2 the full load current. Obviously this would be a custom made switch, and again I think with careful design it can be made fairly compact and low weight to fit on the end of the battery pack. Some of the cost can be defrayed by elliminating the existing charge balancing circuit. I would really appreciate your feedback on this idea.

Ronald Greene: About your zinc fuel cells. One of the frustrating things about many web sites on this type of technology is the vague hype “much better than existing” etc. and not much in the way of numbers. Your link did provide some numbers, finally, which said that the cell has about 200 wh/kg and 225 wh/l. These are about equivalent to better Lithium batteries (better than Tesla’s), but not much. Also it is unclear if this is just for the electrolyte or includes the hopper with the fresh zinc and the collection tank. Their compareson quote that existing batteries are only 3 wh/kg is just plain wrong, even lead acid is about 40 wh/kg. Click on my name for comparison chart. The idea that an individual could purchase a home electrolysis system to reform the zinc pellets is intrquing. This is certainly not existing now, but still there are many unanswered questions, How efficient is the Fuel Cell? How efficient is the Reformer? From the numbers above the range would be about the same, not 7 day’s worth. Where did you get these figures from? You suggest, correctly I think, that the Zinc fuel cell would not be able to provide full power for acceleration, and a secondary system of batteries would be required that could be re-charged from the zinc fuel cell. This requires added complexity, weight, and cost, so the range would not be as good as present. You say this is available now, therefore you should be able to tell us the cost and answer my above questions about efficiency. Please do so on a future post.

Roy - The “7 Day” quote is a marketing ploy… it’s based on an assumption of an average driver going 33 miles per day - 7X33=231. So Tesla’s Roadster also holds a week worth of charge, but for what it’s worth so does my cell phone. I still charge it every night just in case.

Another feather in New Mexico’s cap?

www.fusor.net/board/view.php?bn=fusor_announce&key=1173455489&site=fusor
www.emc2fusion.org/

The biggest weakness in any BEV is that there is no way to recharge the batteries as the stored energy is used. The Chevy Volt
is going to use a ICE powered generator to extend the range of the car to over 600 miles. GM then also suggested that a fuel cell
could be used as an alternative range extender This was why I suggested that Tesla give the idea some thought because it
would be a win-win situation for them. The biggest weakness of the fuel cell is that is does not have a large reserve of stored energy . However, if you combine a fuel cell with a large battery system you then have the best of both worlds. For example, to extend the range of the Telsa all you would have to do is to carry the zinc-air fuel cell as shown in the picture in the trunk. You run the Tesla as far as it will go 200 miles minus the weight of the fuel cell. You then connect the fuel cell and recharge the batteries which would then after sufficient time would allow you to run the car again as far as it has been recharged. Thus, a fuel cell acts just like any other electric generator and will always extend the range of any BEV despite its own added weight.

The only question is how much farther will it go. I was of course interested to find an answer and was lucky enough to find a company who already did the experiment. A company in Mayaysia did just such an experiment. In a test run of a hybrid vehicle using a fuel cell as an electric generator to recharge nickel-zinc batteries, the EV went over 516km or about 320 miles. I would assume that if the batteries were Li-on that you could do even better and break 400 miles. See website www.3nw.com/energy/resources/metal_fuel_cells.htm The addition of the fuel cell to any BEV then converts it into a series
hybrid. Therefore, you should be able to reduce the size of the battery pack while still getting excellent range and performance.

Zinc-air fuel cells are now as the picture shows see my eariler post in their sixth generation and have made remarkable improvements and using them to recharge a BEV seems to be an easy way to extend the range and remove the necessity of having to recharge your batteries from the grid every night. As for cost fuel cell batteries are cheaper than petrol by about 10 times, non-flammable and provide higher power and higher energy because chemical energy is directly turned into electrical energy minimising energy loss and therefore cost only about 10sen per kilowatt per hour of usage in Malaysia. To me if you can replace some or all of the energy wihile you use your EV you are just going go a whole lot farther. We can thank GM for pointing the way but then they learned the hard way that the invention of the electric car was incomplete without a generator to extend the cars range.

Martin, Marc,

What driving cycle was modeled (or driven?) to derive the older, 110Wh/km number cited in your paper “The 21st Century Electric Car” (www.teslamotors.com/display_data.php?data_name=21stCentElectricCar )? The number 110Wh/km seems to be the one “sandbagged” down from 165 mpg to 135mpg. Footnote 8 in the paper references the INL testing of the EV1 (avt.inl.gov/pdf/fsev/eva/genmot.pdf ), but does not specify whether reference “for comparison” should be made to the 60mph constant speed driving cycle or to the SAE J1634 test procedures.

Thank you.

AC Propulsion designed a “range extender” trailer for their tZero car.

Tesla Motors’ CTO, JB Straubel also designed a lower cost range extender for one of his EVs and discusses why a mechanical pusher offers better fuel efficiency than a towed generator.

Finally, even GM designed a series hybrid version of the EV1 which used a high-efficiency, multi-fuel turbine engine.

Given their CTO’s previous experience, Tesla Motors seems very likely to consider a range extender for the Whitestar. For the Roadster, however, I think the range limit will likely be driver comfort and not the ESS.

(Hopefully the blog moderator will inline the above links if the syntax is not correct)

Brent writes, “I’m a little surprised that the extra weight affects the range so dramatically — some 20 percent — while acceleration remains unchanged. I would have thought the opposite, that the acceleration would be much lower, but the range only a little reduced.”

Transmission failures (due to repeated shifting from 1st to 2nd while flooring it) lead to redesign. Redesign leads to more weight but optimized acceleration. 50 more pounds means reduced range.

In Reply to Jim Mapes:
I think you are arguing a different point than me. I was focused on the refueling problem. If the engineers can exceed a range of 880 Miles then all the debate about refueling in 5 minutes would be moot. As for your complaints about the 55MPH speed limit I used in my ROUGH equation I think your missing another point. That being the 16 Hours part. When you can drive your truck that gets 8-12 MPG for 16 hours at 55MPH or 75MPH without refueling once let me know.

Question: Is there a fuel cell in your future? Chances are that you will be using fuel cells not Li-on batteries in the very near future.
The Electric Fuel company has now developed an ultra high performance zinc-air micro fuel cell that could power your notebook computer for over 16 hours. These new zinc-air micro fuel cells are expected to be available for by as early as the second half of next year and are intended for use in notebook computers, hand-held power tools and etc. These micro fuel cells have a specific energy of 400 Wh/kg and pack 50% more energy per ounce than the 3300 mAh cells used in Electric Fuel’s instant power batteries. These new fuel cells have a capacity of 30Ah and weigh only 3 ounces and can be expected to last over 16 hours. How long does your computer
last on your Li-on batteries? How can fuel cells outperform Li-on batteries. The answer is very simple for the same reason that Tesla’s battery pack weighs 900 lbs. The main reason the battery pack is so large is that only a small percentange of it can actually
be used like 30% or else the life of the Li-on batteries will be shortened. Not so with a zinc-air battery as they can be deep-cycled until the very last drop of energy is used and then they can be refueled with no lost of performance. Fuel cells allow you to use 100% of it’s energy and therefore you can really use a much smaller battery pack reducing the weigh of the EV and extending its range. This is why there will be a fuel cell in your future. See www.electric-fuel.com/pr/2001/pr05112001.shtml

# Mark wrote on April 23rd, 2007 at 5:33 pm
## AC Propulsion designed a “range extender” trailer for their tZero car.
## Tesla Motors’ CTO, JB Straubel also designed a lower cost range extender for one
## of his EVs and discusses why a mechanical pusher offers better fuel efficiency than
## a towed generator.

## Given their CTO’s previous experience,
## Tesla Motors seems very likely to consider a range extender for the Whitestar.

I brought up the pusher trailers in the early days of this blog, and the response from Tesla was (basically) “we don’t want to have anything to do with anything that burns fuel”.
It seems that the party line is “electric only or bust” right now.

I think it makes sense for them to stick to their ideals (for now) and not be viewed as a “hybrid company”. The Tesla angle seems to point a finger at the hybrids and label them as “weak sell-outs” that aren’t trying to find the real solution.

Anatoly wrote “Changing weight from 2500 lbs to 2700 lbs should proportionally increase just rolling resistance component by 8%.”
Probably Tesla didn’t want to compromise on any of the roadster’s sports car features: 4 sec acceleration 0…60 mph and 135 mph top speed. The later rules out an increase in gear reduction ratio (would have traded top speed for torque available at the rear wheels) or regrouping cells electrically into more parallel strands (same thing electrically). Motor peak resistive losses can easily be handled by higher capacity heat sinks and A/C system mentioned by Martin. Therefore my guess they had to squeeze some 8% more amps from their ESS (to accelerate 8% more mass in the same span). Obviously higher discharge rate and lower discharge depth both shorten cycle life of conventional Li-ion chemistry, so they opted for 16% (?) lower capacity cells with “higher abuse tolerance”.
To me this is bold proof of Tesla’s long term business strategy. Protecting buyers’ residual battery capacity five years down the road creates long term customer loyalty and trade mark image. Another company could’ve silently “forgotten” about 100,000 mile life, to make some quick profit for a couple of years. On the contrary Tesla genuinely want to evolve a long-term (20+ years) enterprise with a significantly impact on road transportation.
I’m convinced that Li-ion technology will improve quickly, allowing Tesla to greatly surpass original range estimates soon, and simultaneously lower battery depreciation cost over the car’s entire life. Including this website, open honest communication style, and future customer service centers, they so far seem on the right track.

Speaking of the WhiteStar (in several comments above)… The press release about the Albuquerque plant said that construction would being in April 2007. There are just 6 full days left in April as of this afternoon and I haven’t heard or read anything about a ground-breaking ceremony. I hope the plant isn’t already falling behind schedule.

# Doug @ Stanford wrote on April 24th, 2007 at 5:23 pm
## www.vanityfair.com/politics/features/2007/05/tesla200705?currentPage=1
## I wonder about their fact checking, though, since there were several odd mistakes I noticed.

Yes, Doug I noticed those same mistakes that you saw and posted them a few hours ago in the old blog page that takes a jab at the press:
www.teslamotors.com/blog3/?p=53

Still, those seem like “honest mistakes” (that probably should have been caught in a proof-read), but I found many other things I know about to be spot-on in the article. I still give the article a “thumbs up” even though it has some small detail problems. I liked the way they gave the reader a “Cliff Notes” version of the “Who Killed the Electric Car” plot, along with a condensed Tesla history that filled in some details I never heard of before. I thought the author did a good job of touching on a lot of important points and then moving on without getting bogged down or overplaying them for what they are worth. The drama of the Elon/Martin/Ian dynamic (in what actually would get built) is fascinating. In my mind those are “famous” meetings and so it was fun to hear them recounted. (Those three guys had the same dream, but Elon wants the dream car, Ian wants the race car, and Martin wants to save the world!) I am sorry that there wasn’t room for Ian in the end, and I cheer on JB as it seems he got the opportunity of a lifetime here.

My primary excitement with Tesla has been the product they are building, but learning some of the story of the founders offers a whole additional level of interest.

Dale- being in architecture , when I heard the plant would start being built in April I was very surprised-it takes a long time to draw all the working drawing plans (arch., structural, mech., plumbing, elect., civil-plus soils report, energy calcs.). Not only that, design & design deveolpment dwgs. can take weeks. Then there’s zoning design review, which can take 45 days (at least where I live)-but you can be doing working dwgs. at same time . After working dwgs. are submitted it takes usually about a month for the city to do planscheck, then maybe 1-2 weeks for architect & engineers above to return their planscheck comments. Some cities have “express planscheck” in one day if you pay maybe $3000 or so. If not, sometimes you can at least get a grading permit first & start doing that. Unless Tesla was doing design development dwgs. & drawing up plans for a generic site before Albuquerque was picked, it would (normally) be impossble to break ground in April. But iIf Tesla is doing a generic pre-fab metal building- or reusing (with tweaks) a warehouse /factory type set of plans done for some other company use before, this could all , obviously, be speeded up greatly. Maybe that’s what Tesla’s doing.

To David related to April 23rd, 2007 comment :

My conservative expectations with batteries are coming from the same concern you have that Li-ion batteries are losing capacity just by time without been used. Consumer electronics batteries typically works for about 3 years. Nothing much is known with Li-ion reliability beyound this lifetime. With say moderate driving of 15000 miles a year you could end up losing significant fraction of total range (say degrade range from 200 miles to 100 - 150 miles) after just about 3 years and 50000 miles. It is very difficult to guarantee up front that nothing like this would happen with real car usage by ordinary people.
Also thermal cycling related to outside weather would likely reduce batteries lifetime. Nobody has any experience with using Li-ion for cars for many years of routine driving so it may be expected something bad.

After couple years it would be clear what is the final outcome with Tesla Motors ESS. Hopefully it would be much better than my conservative estimates for range and ESS recharging lifetime. But it remains to be verified what would be real outcome.

To Wolfgang :

I agree with you that demonstrated communication style of Tesla Motors looks assuring. Just range reduction may not be the last “feature reduction” kind of discoveries about real car. Practical EV car usage experience with mass produced car and ordinary people not tweaking the car they own is very limited. As a result nobody honestly have any practical idea how ESS would hold range with time. My point is that even if range would be degrading with mileage faster than expected the roadster would still be a big technological step forward.

Tonight’s PBS “Frontline” show on global warming & politics once again shows what a total failure ( to put it diplomatically instead of in halibut- like terminology) Bush, Cheney & Company are (across multiple fronts) . In election campaign against Gore, Bush actually promised he would inact mandatory carbon cuts, and continue Kyoto talks/process. He backed out on both. Then his admin. tried to squelch latest scientific consensus on global warming, including trying to silence NASA climate scientist James Hansen-who first testified to congress in 1988 warning strongly of man-made global warming-saying then that it was “99% certain”-almost 20 yrs. of almost total climate inaction, thanks to Corp. America vested interests controlling govt. action.Clinton/Gore tried to take action-but were totally blocked by congress-especially reps. from gas, oil & coal states. I can’t wait till Jan. ‘09, when Bush/Cheney et al become a pathetic, halibut-like footnote to history. Next job will be to assign the same footnote those of like mind in congress.

TEG wrote on April 24th, 2007 at 6:01 pm
#Yes, Doug I noticed those same mistakes…
#Still, those seem like “honest mistakes”
Teg, I intended my tone to be more humorous than critical. (Hence the use of the smiley. ) I found the article well worth the read. Just thought those mistakes were kinda funny since they’re so easily checkable. That and “Sand Lot” makes Menlo Park/Palo Alto sound like a wasteland.

To: Martin Eberhard who wrote on April 18, 2007 Range Reality. Yes, an increase in an EV’s weight does seriously effect its range.
For example, a Solectria Sunrise has recently set a documented distance record of 375 miles. How was it done? The Solectria Sunrise is an all-composite light weight car designed from the ground up fully loaded with batteries weights 2300 lbs and it can
carry 4 adults. Biggest weakness is its single speed transmission so its 0 to sixty takes 17 seconds. The company that builds
the car is called Azure Dynamics and what will be their next step. They cite an article in Scientific American, “The benefit of going hybrid is substantial - even when compared to so-called zero emissions vehicles — an all-electric is 1/10 as dirty as a conventional vehicle while an HEV can be about 1/8 as polluting”. With good design, HEV’s can also achieve several times the fuel efficiency of a gasoline-powered vehicle. I agree that the benefit of going hybrid is substantial but not with hydrogen which creates a very expensive and complex car which is unnecessary expensive. For example, ZAT recorded 478 miles on a single charge in a delivery van using Zinc-Air batteries. You will notice that the zinc-air battery powered van was much heavier that the Solectria Sunrise but beat its record by over 100 miles. If you then use the zinc-air batteries to recharge the batteries it becomes a series hybrid and the weight of the car becomes even less important because you are replacing energy while you are driving the EV. This is why the Volt is going to do so well because you will drive it just like any other car and not think twice about it. On the other hand,if you are driving a Solectria Sunrise you will have to worry about how many people you carry as this will affect the mileage of the car as well as hills and weather. Thus, I must agree with Azure Dynamics that the future will belong to hybrids but not HEV’s but series hybrids using metal fuel cell technolgy.

# Anatoly Moskalev wrote on April 24th, 2007 at 10:44 pm
## To TEG:
## If mileage improvement with speed numbers presented by Jim Mapes
## are real they just reflect the fact that his car ICE engine has sharp
## efficiensy degradation with reduced power.

Yes, I had thought about that, but even so, the values he presented seemed beyond what I would expect even from a big ICE engine that runs poorly at lower RPMs.
Take into consideration that a streamlined low-CD vehicle will have an easier time slipping through the aerodynamic drag, yet the purported “more fuel efficient at higher speeds” vehicle is a truck which likely has a poor CD.
I suspect that values presented were exaggerated in an effort to make people think that slowing down offers no consumption benefit, because the person making the claims enjoys driving fast and wants to feel righteous about it.

A quick search shows other large displacement truck drivers slowing down to save fuel:

forums.thedieselstop.com/ubbthreads/showflat.php?Number=2464095
“”I’ve got a 2001 4×4 Excursion Limited equipped with the good ‘ol 7.3L PowerStroke….
I spend a lot of time in the granny lane doing my 60-65 MPH, but considering that I only save 2 minutes traveling at 75 MPH over 60 MPH in a ten mile stretch, I’ll leave a couple minutes earlier, stay at 60 MPH and save fuel and wear and tear on the truck.”"

townhall-talk.edmunds.com/direct/view/.ef0f663
“”I am on my second F250 V10 4×4 SC 3.73
…At 75 to 78 mph I get 8 mpg
…At 68 to 70 mph I get about 9 mpg”"

Jim Mapes posted in another EV forum over a year ago his “opinion” that 90+MPH is more efficient:
www.evworld.com/news.cfm?newsid=11473
“”Jim Mapes: …the more efficient speed of 90mph+…”
In that posting Jim suggested that EVs need to be able to go 90+ MPH so that they can reach more efficient speeds. This just seems like a wrong & misguided assumption to me. If he somehow calculated that his truck got better mileage going 95MPH downhill with a tailwind it doesn’t seem right to start applying that to other vehicles as a general suggestion.

Jim: how exactly did you calculate your truck’s MPG at 95MPH? All the data I can find suggests that your numbers are contrary to what others experience. What sort of grade/wind/load/altitude factors were involved when you took your measurements?

Anatoly- AC Propulsion “T-Zero” li-ion powered car that inspired Tesla is ,I’m guessing. still around & being driven-must be around 4 yrs. on those batteries by now-wasn’t Tesla started in 2003 after Martin drove that car for a few months? Need to check T-Zero batteries / range now.

www.msnbc.msn.com/id/18307782/

“The Great Global Warming Swindle”

I recall several people referencing this movie months ago. Headline: Scientists want edits to warming skeptic’s film! In other words the film is extremely misleading and saturated with mistakes. See above link for more details if you wish. I’m very proud of the accomplishments from “everyone” at Tesla Motors. Keep it up, full speed ahead. Anyway those are all minimal although necessary modifications you speak of in your blog. Get some apparel out guys so I could start brandishing it. Please.

By the way - the “KillaCycle” evolves:

www.killacycle.com/
“…we clocked 8.168 seconds at 155.78 MPH…”
“…We put in another 110 of the most powerful Li-Ion cells in the world
to make a total of 990 A123 Systems M1 cells in the bike.
This pushed the power output to over 350 HP.
We are now able to draw 1575 amps from the 375 volt,
7.5 kW-hr battery pack.
There are just 161 lbs of cells in this pack.
We call the A123 Systems battery pack ‘Mister Fusion’ because
it acts like a bottomless pit of power and energy on the track.”

Comments above on the subject of trailers, like JB Straubel’s, makes me wonder something. Will the Roadster, and eventually the Whitestar, come with a towing rating like most cars? Or, perhaps more importantly for the owners, will there be features in the rear frame for hitch receivers to bolt too? I know that I’ll want to put a hitch mount bike rack on my Whitestar…

-Bill Davis
Union City, CA

The problem is battery weight and capacity. It probably will be necessary to look into the possibility of acquiring a battery manufacturer; so that a source is readily available once a sufficient number of orders for future models is achieved. Perhaps a Mexican plant for lithium-ion batteries could be built so that labor costs can be kept low. An additional expense however. Perhaps a hedge fund with a green portfolio of investments, where a portion of the management fees might be designated for battery manufacture, might prove a solution. With a million multi-millionaires in the United States alone, the potential market certainly exists for all-electric vehicles; provided, of course, that battery weight could be lessened and battery performance increased. And to achieve that, sources of battery suppy have to be guaranteed, and that can best be done by controlling a manufacturing process for lithium-ion car cells.

# Richard wrote on April 26th, 2007 at 4:08 pm

#OT for this blog, but…
# Excellent article in popular science.
# www.time4.com/time4/microsites/popsci/futureofcars/tesla_p1.html

Does “OT” stand for “off topic,” here, or “on target”? If you go to said article, the first page deals with the “range reality” JB Straubel faced with his drag-racing electric Porsche conversion car, many years ago. That seems fairly “on target” to me…

# T.J. wrote on April 25th, 2007 at 6:22 pm
## AC Propulsion “T-Zero” li-ion powered car that inspired Tesla is
## ,I’m guessing. still around & being driven-must be around 4 yrs.
## on those batteries by now-wasn’t Tesla started in 2003 after
## Martin drove that car for a few months? Need to check T-Zero batteries / range now.

soundingcircle.com/newslog2.php/__show_article/_a000195-000511.htm
“” August 27th, 2003 the Li-Ion tzero was driven for the first time. “”

www.acpropulsion.com/tzero/efficiency.htm
“” October 3, 2003 - TZero is driven 302 miles without charging. US 101 Silicon Valley to Santa Barbara is driven at 60 mph “”

www.electrifyingtimes.com/EVS-20_mark_hanson.html
“” November 22nd, 2003 ::: EVS-20 :: Alan Cocconi’s AC Propulsion T-Zero demo’d 280 miles per charge on Li-Ion batteries from LA to Vegas. “”

www.electrifyingtimes.com/earthday_beverlyhills.html
“” April 22, 2004 : Tom Gage told ET that the Li Ion battery pack in the t-Zero has now passed 20,000 miles and is not showing any loss of capacity. “”

www.acpropulsion.com/media/robbreport.htm
“” August 2, 2004: AC Propulsion has delivered three Tzeros—the first (upgraded to Li-Ion) belongs to AC Propulsion and the other two are in private hands… AC Propulsion is leaving the car-building business so that it can concentrate on making drive systems for two other companies that are developing electric descendants of the Tzero….” (Tesla & Venturi?)

www.acpropulsion.com/tzero/development.htm
“” 81,000 miles on prototype #1 “” (the one with Li-Ion cells)(not sure how many of those miles are on the Li-Ion pack, and how many were racked up before they redid the power pack)

All the mention of ACP in 2006/2007 has them showing off their eBox (Scion conversion) prototypes, so it appears that they have taken the T-Zero out of the limelight to focus on what they are actually trying to sell now.

More on Li-Ion TZero here:
www.acpropulsion.com/tzero/
mysite.wanadoo-members.co.uk/ecotech/tzero2.htm

Best wishes for 1st of May, Martin.

finance.senate.gov/sitepages/hearing050107.htm

Will you be able to post the details of your presentation?

Good to see that Jeff Bingaman has had first hand experience of the Roadster in advance of the hearing next Tuesday.

bingaman.senate.gov/news/record.cfm?id=273269

I imagine that Craig Thomas will be there to push the development of coal. Fair enough. If you are going to use coal, it makes more sense to use it to generate electricity rather than the lower yield option of hydrogen.

Martin,

Talk to Boring and Airbus about weight gain and the impact on performance (range/payload). You are still doing a great job and I look forward to being an owner in the future. You are creating the future!

Chris

Keep the big automakers at their KNEES!!!

I love the way your company WILL TOPPLE the poluting GIANTS!

William O’Conner: Right idea, wrong solution. Tesla has it right. There is a large number of battery research companies working on a large diversity of designs. No one knows which will ultimately succeed. Tesla is a car company. Right now they are free to switch to any new technology that is successful. They believe that the route to affordable batteries is to use what is most popular, hense the decision to use common 18650 series because that form factor is an industry standard made by several competing companies.
Tesla’s success will increase the demand for these batteries, but I don’t believe that the world supply is so restricted that Tesla will be unable to purchase what they need. The big American car companies have a very close relationship with A123 and Saft battery companies, and I believe that they would prevent Tesla from buying (possibly by simply asking too much money) from these companies, but there are lots of others to choose from. The car companies, along with Government assistance, are dumping almost $100 million (more than the total investment into Tesla) into these two battery companies for research, and they are acquiring many patents. If they succeed in producing the best batteries, then they will probably prevent Tesla from using them, and other battery companies from infringing on their patents. I personally hope that other companies will triumph. I don.t think that patents should be allowed to prevent competition, just enforce a fair licence fee or royalty.

# Susan K wrote on April 28th, 2007 at 8:30 am
## Would you reassure us that you will not sell (or be forced to sell out) your battery technology out to the ICE/oil companies?

Tesla doesn’t (as far as I know) own any particular “battery technology”. They seem to be trying to avoid getting stuck in a sourcing battle for batteries by using commodity laptop batteries that aren’t being made for a particular application in the USA.
As has been mentioned before, the “best of breed” Panasonic NiMH batteries circa 2000 got pulled from the US BEV market by way of Cobays patent litigation brought on (in part) by a US oil company.
Cobasys is now partnering with A123 which offers (perhaps) what some consider the current “best of breed” Lithium-Ion for auto use:
www.evworld.com/news.cfm?newsid=13809
It would probably be risky if Tesla were to start making vehicles powered by A123 (or Saft) batteries as big US auto & oil companies seem to be in a position to steer who can get them an who can’t.
(In other words they are likely to end up in GM hybrid vehicles, but perhaps not for selected other vehicles).
Even if Toyota had wanted to continue making NiMH RAVs they were effectively blocked by Cobasys. Hopefully Cobasys never has a way to block Tesla sales.

================================================================

Here are some recent news stories that re-emphasize why we need to get away from ICE vehicles, and move on to BEVs ASAP:

www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2007/04/29/BAGVOPHQU46.DTL
www.mercurynews.com/ci_5772707

Dear Tesla Genious’
I had a glimpse of your product in a magazine recently which prompted me to read your website almost cover to cover. I’ve dreamed of a vehicle like this for many years but, alas, my engineering career had taken me in other directions.
Someday I want to be one of your customers. Where I live in northern Alberta, Canada I’d like to see your product proven in our harsh winter climate where it somtimes gets down to -40 deg C. Hey, If you want to do some product testing, PICK ME !!!! I currently do a rural comute of 170 km.
I wish you great success.

# Martin Eberhard wrote
# …it helps drive our own technology internally, and it will help us
# reach decent purchasing volume on battery system components
# - obviously especially the cells themselves.

How many of those things do you have to buy before you are considered to be purchasing in “decent volume”?

300 (rough number of Roadsters) x 6831 (cells per Roadster) = 2,049,300.

Even if I were only buying two million paper-clips, I’d get a pretty good discount. Are you waiting to get “green stamps” too?

# Martin Eberhard wrote on April 29th, 2007 at 9:41 pm
## Al and I spent two hours together in that car on the track at Sears Point during the Challenge Bibendum. What fun!

Any thought of bringing a Tesla Roadster to an upcoming Bibendum?

17 Nov 2007 in Shanghai…
www.challengebibendum.com/

Like in Al Gore’s “Inconvenient Truth” it would be a good idea to inspire more Chinese to aspire to use BEVs…

Argh!

The interesting stuff starts on page 8 NOT

This is a novel approach to capture wind energy from passing vehicles. It could be used in conjunction with recharge stations one day.

www.autobloggreen.com/2007/05/01/highway-wind-turbines-to-capture-energy-from-passing-vehicles/

The text of Martins testimony is now available. Great read.

finance.senate.gov/sitepages/hearing050107.htm

I am a big Nikola Tesla fan myself so I don’t understand why you have not tried to use his dynamo for on the road recharging. Weight might be a factor, but not if you replaced much of the parts with lighter weight composites available today. I have several other ideas for on the road recharging, but will not leave them on a blog. I hope you are not taking any of this wrong. I am absolutely amazed at what you guys are doing. Maybe one day we’ll see an all electric racing circuit. Then there will be plenty of sponsors to fund R&D for the future of electric cars. Good luck on everything you guys do.

Jeff

Oh it was at the Finance comittee. duh!
Look forward to listening tomorrow.

www.senate.gov/~finance/sitepages/hearings.htm

#garret smith asks:
#Why not push for standardized batteries?

This idea is brought up fairly regularly. The general problems:

1) Economics — there are too few electrics planned in the near term for any service stations to carry them. Longer term, the economics might work out, but then there’s the problem with …

2) Engineering — battery packs currently are heavy and large, like around 1,000 pounds and the width of the car. It would take some kind of machine to install them, and they have to be secured in a way that they don’t come shooting through the car in an accident. In the time required to swap out a battery, I’d guess you’d be able to charge your battery half way or more. Still, engineers may be able to work out these problems, but then there’s the problem with…

3) Human impulse — battery packs tend to degrade with time, making a new pack more valuable than an old. If I got to swap out my old pack with a new one, I might never return the pack to the station for the next swap. I’d just recharge it at home, and have a better car. Still, I guess you could figure out some kind of battery-grade exchange formula, but then there’s the problem with …

4) Advances in battery technology — Batteries with double the energy density of today’s models could be available in as few as 10 years. That means your car would go something like 400 miles to a charge, which is enough for most days’ worth of driving. (For me, anything longer, and I’m on a plane.) In that case, I doubt many people would care about how long it takes to recharge, and the hassle of stopping at a service station wouldn’t be worth the charged battery.

If anyone reading here would like this congress to vote to give subsidies to help us EV buyers afford the early ones to get this industry competitive with Detroit vote here - after 6pm tonight

www.dailykos.com/user/dotcommodity

when I put this up for a vote that we will send to congress. They are considering subsidies for EVs up to cars $6000, businesss cars $25,000 and heavy trucking vans $40,000 (and conversions (ie make to Prius a plug in)

To put this in perspective the Japanese govt gave early adop[ter hybrid buyers a 50% subsidy in the 90’s,

www.evaap.org/japan.html

and look where they are now in relation to Detroit. I am a big believer in market intervention when our dear planet depends on it, and this is a rare moment of common sense in congress.

Mr. Heckard: Tesla will build a cheaper vehicle in the future. We just have to be unbearably patient. Regarding Steorn’s Orbo technology…they are essentially claiming the first law of thermodynamics (conservation of energy) does not apply to them. I will be very surprised if we ever see an Orbo charge anything (beside Sean McCarthy’s wallet). Maybe they’ll prove me and everyone back to Galileo wrong though.

To anyone considering the claims at the www.steorn.com/ and similar sites, don’t bother. How anyone can give any credence to these types of claims is unbelievable, but understandable considering the ongoing success of the Nigerian financial scams: a majority of humans are stupid, and there is no fix for that.
Get this through your head: There is no such thing as Free Energy, whether through the idiotic claims of Steorn, or using in-wheel generator, wind turbines stuck on side mirrors, etc., etc. Geez, this is frustrating….

To Al Levesque:

As history demonstrates alchemists promised to make gold from mercury or lead to rich people in Europe for many centuries. They profit from this and have some life but nobody delivered. Since discovery of energy conservation in physics around 1842 periodic floods of free energy proposals in all sorts of way keep coming and going as regular as waves on the beach. So far nobody proved to be able to violate conservation of energy but many claimed they did. I think you are too emotional about this. It is just human nature to be unbelievably diverse in the way of thinking and in foundation of what people trust without proof. So some people deny even the most fundamental facts or laws of nature discovered. Some call it stupidity but at deeper level of thinking you would realise that allowance to disbelieve even the very core principles presumably proven long ago and forever is critically valuable for society to keep developing. I think the only principle to follow is that extraordinary claims need adequately extraordinary proof. Free energy proposals challenge the conservation of energy law verified by whole technology of the world operation for 150 years already. So such proposals should be simply managed to working devices and provided to the public in mass quantity before even bothering to consider. Proponets just should do it at their own cost somehow. Until this is done such proposals basically better be treated same way as dreams and rumors. They are not from the real world. They are either more or less creative attempts to profit from human nature in not the most honest way or just plain dreams in a “…how nice it would be if…” style. Either way I see nothing to be overexited about. People are extremely different and are dreaming about unbelievably diverse things and it is good. Allow them to enjoy life in their own way.

#
Al Levesque wrote on May 3rd, 2007 at 4:55 am

To anyone considering the claims at the www.steorn.com/ and similar sites, don’t bother. How anyone can give any credence to these types of claims is unbelievable, but understandable considering the ongoing success of the Nigerian financial scams: a majority of humans are stupid, and there is no fix for that.
Get this through your head: There is no such thing as Free Energy, whether through the idiotic claims of Steorn, or using in-wheel generator, wind turbines stuck on side mirrors, etc., etc. Geez, this is frustrating….

Reply,

I grow tired of ignorant minded rants from people with an inability to accept that in science, anything is possible. Half a century ago people thought it was impossible to break the sound barrier without a catastrophic disaster, this was dramatically disproved and the world of aviation never looked back. I could go on and on about so called rules and laws of science that have been shattered. Maybe thermodynamics will be the latest casualty……………… stay tuned.

Those who don’t have an open mind and are unwilling to think outside the box are fools!

@ Mr. Know it All:

Wow. Insults and personal remarks. How mature. I am quite sure that everyone is waiting to hear your opinion. Oh, that’s right, you back up your argument with insults, so probably not.

Don.

Hey Bullwinkle (aka Mr KnowitAll) Perhaps you ought to read more carefully before firing off silly posts.

What Mr. Eberhard said: “At more than 200 miles, the Tesla Roadster will still have the highest range of any production EV in history by a large margin…” Note future tense word “will”. As an engineer, Mr. Eberhard is confident that his roadster will perform very well on the test. Note also that he specfied “production EV”. Not concept car, not experimental prototype, not one-of-a-kind special built just to set records.

The 2006 Honda FCX was certified by the US Government with a range of 210 miles, but this is a PROTOTYPE, and is not in production - and won’t go into production for a year or two, or more, or maybe never. Tesla goes into production this year

As for “Tesla not having a government certified range”, be patient. The government burecracies move slowly, especially when it is NOT the “favored by the prez golly-gee-whiz hydrogen” technology. We cannot blame Tesla Motors for government lethargy.

Of course Tesla Motors have been using their best estimates for range, based on their own tests. What else can they do? The goverment hasn’t done the certified range testing yet!

Who wants to bet that the Roadster will have a real world government sanctioned range test result that bests the FCX by at least 20 miles?

i look forward to adding a 300 mile extended travel assesory to the telsa.

Well, Mr. Knowitall, you are still missing the point. That nifty concept Honda FCX demonstrated in 2006 is NOT YET in production, and is NOT YET been leased to anyone at all! The older models that have been leased have not done as well, range wise.

As to what range some future Honda FCX model may get, that is the same type of speculation, supported only by the manufacturers statements, not yet certified by Uncle Sam, that you seem to be decrying here. Pot, meet kettle.

If you want to get a Civic GX and the associated Phill natural gas compressor, feel free to do so. Nobody here will try to stop you. That’s better than pining over a very expensive H2 fueled car that you can’t get now and might not ever be able to own.

Consider this: The cheapest source of H2 is from natural gas reformed with high temp steam, so that’s where most of the H2 fuel for the Honda FCX wil come from. When you consider the energy wasted in the reforming process, and the energy required for compression (much higher pressure than in the Civic GX), it turns out that the Civic GX might actually use less natural gas than the FCX! And, of course, don’t forget that the Civic GX is much cheaper than the FCX - less than 1/10th the price - and it is available now, not in some indefinite future.

Of course, you’d never want to compare the efficiency of an electrolyzer/fuel cell/compressor combination (24%) to the efficiency of a Tesla charger and battery (85%), or compare costs. It would severely dampen your Hydrogen Hyped enthusiasm.

Don’t worry about the compromises. Just don’t ever stop. What you are doing is much bigger than just building a car.

# Paulo Lopes wrote on April 23rd, 2007 at 10:49 am
## The Tesla Roadster is featured in this month’s Vanity Fair “Green Issue.”
## The full article can be found on their website,
## www.vanityfair.com/politics/features/2007/05/tesla200705?currentPage=1
## It is a great article about Tesla Motors and the Roadster.

# TEG wrote on April 24th, 2007 at 1:40 pm
## Yes, that is a really good article.

Well, at first read, I thought it was good, but I since then learned that the technical errors are not just typos. Apparently it distorts many facts, so perhaps it should be read with a big “grain of salt”.

Dear Martin,

I live in Switzerland and I really, really want to buy a Tesla. Why won’t you sell me one?
I would not mind taking it to the UK for service at Lotus.

Please……

Okay.

Anyhow.

@ herr Niels: I am sure no one wants to deprive you of a Tesla … I suspect, however, that the Swiss version of D.O.T. just won’t let you drive it there. But feel free to smuggle one into the living room. It has a great stereo and what a great conversation piece, dah?

@Mr. Kelsey: Perhaps the additional weight will be a positive influence on the roadholding abilities? After all, actual traction is all about the dynamic coefficient of friction and the actual number of pounds per square inch of tire contact, n’est pas? And the entire insurance industry will tell you that bigger is better in any unintentional metal-to-metal meeting on the road.

@MrKnowItAll: Uh … I think the handle speaks for itself, eh?

@David_42, Mr. Merrit, et al: 100,000 miles? Aren’t they just getting broken in by then? Of course, one can only hope that the engine maintenance has been accomplished properly. My personal best is a 1988 NUMMI car which died of collision at 236,457 miles. But the 1992 Honda Accord Wagon is getting there at 138,536 miles. The poor 1997 Miata has only 46,880 miles. I need to commute more than 15 miles to work apparently.

@everyone else: Thank you all for coming and sharing. I look forward to that occasion when your Tesla hits the used car market here in upstate New York so I might partake of the excruciating delight. Sunny days.

Jim,

Do you have any news of the orgainic battery that NEC came out with? You know the one that is suppose to only have to recharge for 30 seconds to recharge to 80 percent it was suppose to be cheap to manufacture maybe a good match for the roadster and much more enviromentality friendly also toshiba had a different fast charging one.

Also what about putting on some super ultra compassators to directly take the full charge of the regen brakes with a run over into the batteries seems like a smart way to gain range and 0 to 60 speed seeing as they can dump their load of energy much more quickly also you could use that solar panel to recharge them.

Allen, putting a fan on the car to harness the energy of passing air or pressurized intake air would put drag on the car, slowing it more than the fan’s energy could make up for. It’s basically the concept of conservation of energy.

I am very skeptical about your car. There have been promises that have not been shown to work with a test car, and misleading statements have been made, such as the one to the NY Times columnist David Pogue that the epa reported 245 miles per charge. They haven’t tasted your car, have they, don’t you conduct simulations on a dynamometer, and offer no proof of the results? Maybe I’m wrong, but the whole operation sounds like a clever scheme. You would do better to appear more honest in your presentation. Don’t say what a Telsa can do unless you have a running car that performs as stated. Have an independant firm do a test of your prototype and issue a report, otherwise is sounds like a repeat of the unfulfilled promises of radical cars of the past. The Tucker is an example. You are taking deposits on the cars. Are they refundable at the depositors choosing? Are you not trying to raise money from the public without an offering being made in compliance with SEC regs? I wish you well. It’s just that your presentations are suspicious. Do you have a Tesla car that is roadable that has gone 200 miles, on a charge? If not, don’t sound like you do if you don’t for that’s misleading.

—

Editor’s surprise: We’ve made every effort to open a window into our development process, particularly in the blogs, for anyone who is interested in learning more about the company. We’ve shared both the gain and the pain. I recommend you read through some of the blogs and our FAQs for answers to many of the questions you pose. Here are a couple of places to start:

- Our blog and press release on the Roadster’s latest range numbers (We include a great photo of the Roadster on a dynamometer.)
- Customer drive blogs
- Refundable reservation payment FAQ

• Marc wrote on October 3rd, 2007 at 11:31 pm

  For some time, I am closely and exitedly following the news and blogs about the Tesla roadster. I’d love to see this great product here in Switzerland!

  I recently came across a startup company from the ETH Zurich (Kringlan, www.kringlan.ch) that aims at selling very light weight rims made of carbon-fiber-reinforced plastic. They claim one can reduce the overall energy consumption by 6 to 8% and make the vehicle even more agile due to less unsprung rotating inertia (sorry for my English…). Currently they undergo accreditation and will deliver their product early next year.

• Bruce Allen wrote on October 21st, 2007 at 2:02 pm

  “Even with the demands of charging and discharging the battery pack on a daily basis, the batteries in the Tesla Roadster will give you more than 100,000 miles of peak performance driving. After that point, the battery will see only gradual drops in performance over time.”

  I’d really like to know if tesla engineers actually did the life cycle tests on the battery to confirm the 100,000 mile figure. Commodity cells generally give you about half of their original charge after only a few hundred cycles at full or 3/4 discharge. Even with all of the sensors and cooling system built into the roadster’s pack, I’m skeptical about this pack lasting for 100,000 miles of american boneheaded driving. I don’t think the average blogger here has any experience whatsoever working with batteries.

  I have found that every company I’ve dealt with so far has overexaggerated the life cycle of their battery systems not necessarily the performance. It’s one thing to drive 245 miles on one charge and another to only be able to do that for a couple hundred charges and afterwards only being able to go 100 miles on a charge, which I think is what is going to happen here. I hope tesla hasn’t put too much emphasis on performance and ignored the life cycle factor, otherwise you’re going to be shelling out a whole lot of new battery packs to customers before the 100,000 mile mark.

  I’m waiting for the nano-phosphate batteries to come to market before I shell another dime of my hard earned money on a replacement pack for my E-motorcycle. I’ll probably do some sort of life cycle test on them on a cell level before I commit to buying anything. Unless you’ ve got thousands of dollars of inherited money to shell out, you’ll just have to wait about 5 or 10 years before you can afford to get off petroleum. Guess I’ll be part of the green movement when it’s already over, and it shouldn’t be a big surprise that it benefits a select lucky few. That’s of course assuming peak oil doesn’t send the world economy into oblivion before then. I’m skeptical as to whether or not by the time tesla motors gets the cost down low enough for the average poor man, The average man will have enough money to put food on his table let alone pay for a car that costs 30K. That’s all great that movie stars, celebrities, eg. the 15 percent of people that control 80 percent of the world’s wealth, will survive and be green whilst the other 80 percent live off of fossil fuels and be forced to pay 5.00pg for gas. It’s just too bad tesla didn’t start 10 years earlier. I hope someone here understands the life cycle of the battery is the real factor in what makes or breaks the car in the long run for the ordinary citizen, not performance.

  good luck

• Jason Schlais wrote on January 18th, 2008 at 11:46 am

  Why cant there be even more ev cars and trucks. We need to have lots of money to have a Tesla sports car. These guys should make a ev. mini van. And make it cost $15,000. It would need to have a heater, but there would be a market.

  Hybrids suck because there is the dead weight factor of a whole motor system while the other motor system is in operation. I just cant belive it the motor is only about 70 pounds in the ev., the battery pack must be about 300 to 500 pounds, Compare that to a hybrid.

  The main advantage to gasoline is it is fast to be refueled. But there are so many disadvantages. Like repairing, mantaining. The weight, leaking fluids, exaust systems.

  The batterys are getting even lighter and holding even more power. Can the batterys also charge faster, be more shock resistant, last longer (how many times it recharges). That would be just great.

  What happens if it falls off of a bridge and lands in the water. Of course all of the electrical stuff gets all shorted out. Does the passengers get electricuted by a monsterous battery pack?

  And does the motor require cleaning like the comm. and replacing the brushes. And getting all the dust out.

  I was a guy that grew up around r/c cars I never would have dreamed we could be driving around things similar to what I was playing with and putting together and fixing. We could almost strap somebody into a r/c car.

• Bill Howland wrote on February 28th, 2008 at 2:45 am

  Note to Jason Schlais:

  1). Tesla claims they have trauma sensors which will disconnect the battery strings in event of a crash, and, then, there won’t be too much electricity flowing outside the big battery box. I’d keep my distance from it just in case. But its pretty well protected physically. Put it this way: If i’m driving the thing and the battery box is smashed, ill be long since DEAD since I can’t withstand that much trauma.

  2). Until they change it (no plans currently from what I surmise), the current motor is a 1/2 revolution per cycle three phase induction motor. The field magnitism is generated by ’slip’ of the squirl-cage rotor bars, and the rotating field is generated by stationary windings. So, the motor has only 3 moving parts: 2 bearings at each end of a rotating rotor. Hence, no brushes.

  Hope this helps.

  - Bill.

• Bill Howland wrote on March 2nd, 2008 at 4:34 am

  Note to Bruce Allen:

  I share you concerns about the batteries, and here’s one proof that there should be concern… There were litterally hundreds of posts on these blogs saying that the tesla charging rate for a 3.5 hour charge (the official Tesla charging time from a completely dead battery) is 70 amps (but they dont say at precisely what voltage. Assuming a pf of 1.0 (best case), and an available voltage of 240 (best case), that works out to 58.8 kwh. Seemed reasonable for a 53 kwh battery pack, until we learn from Engineer Andrew Simpson that at a 4 hour rate it takes 75 kwh. Working that back into the ‘official’ 3 1/2 hour charging time would be 90 amperes (absolute minimum Best Case).

  A 70% charging efficiency rate DOES sound reasonable, but why didn’t they say so in the first place?

  Is there further ‘fudging’ on the battery -life, range, replacement cost, and other concerns to be taking place in the future? Makes one wonder, especially since no-one has bothered to respond to any of my tens of posts.

  - Bill.

  Bill, this is a blog, not a discussion board. If we were to answer every inquiry here we would be swamped and have no time to get other things done. We definitely read what is written and take it into consideration. In some cases the blog moderator may insert a simple comment or response. In this case, I am thinking that a blog in the future that goes into great detail as to our charging specifics would be a good idea. -ed.

• Bill Howland wrote on March 11th, 2008 at 3:38 am

  ed: Well, I have to admit that I don’t see a big difference between a discussion board and a blog, However, if Tesla came out with information in the first place, there wouldn’t be so much ‘discussion’.

  Three Points:

  Tesla’s advertising numbers just don’t make any sense. The ‘official’ charge after driving 220 miles, what tesla calls a ‘dead battery’ (the reason I’m going into such detail is that ‘ed’ chastised me before on the different charging rates and levels, incidentally, I was aware of that before I posted the first time. Sounds like ‘ed’ is setting up a straw man to knock down, but didn’t have anything to do with my post. I was also accused of misleading statements and inaccuracies. I think if ‘ed’ looked and researched precisely what I’ve stated, ‘ed’ would find neither misleading statements nor any inaccuracies. I’ve run into this many times where the blogger has researched the info more carefully, and has a greater grasp of the subject than the ‘ed’.

  1). Either it takes 75 kwh to fully charge the ESS after driving 220 miles, or it doesn’t. Andrew Simpson says it does.

  2). The recent USA today video ‘box’ stated 220volts , 3 hours, is the time to recharge. This is possible only on a 3-phase circuit, since you gain another 1.732 (sqrt 3) times power. I don’t think we are to assume anything other than single-phase charging (eg, 120 volts 2 wire plus ground, or 240 volts 2wire plus ground, (earth for you euro types). On a single phase circuilt, 75 kwh is impossible at 220volts, 3 hours, and 70 amps. I DARE to have ed prove me wrong.

  3). I suspect I’ve caused some red faces since some of my blogs have yet to be ‘moderated’, and other have been obliterated, even though they were certainly on-topic, and not abusive in the least.

  - Bill

  I’m not aware of any post of yours that has been deleted. -ed 

• Victor P. wrote on March 16th, 2008 at 1:57 pm

  Put some capacitors to accept all regenerative current from breaking, if it would be possible to recover 50% of kinetic energy, how long would you extend tesla’s range ?
  Tesla car is a tremendous and necesary seed for this times of oil diminishing.

• Robert Lemke wrote on March 19th, 2008 at 12:55 pm

  On your transmission issue, I’m certain with all the gearheads you have working for you someone has brought up the idea of using a Lenco transmission. I’m curious why you decided against it?