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Tesla Downgrades Range of Electric Roadster

18 April 2007

To improve safety and durability, design changes were made during the building of the first validation prototypes of the Tesla Roadster. As a result, the company has downgraded the electric vehicle’s range from 250 miles to “greater than 200.”

Changes made to increase the car’s safety and durability increased the weight by several hundred pounds. In addition, the company selected li-ion cells with a slightly lower capacity than the largest cells available because the smaller and more mature cells have better long-term durability and higher abuse tolerance.

Writing on his company’s blog, CEO Martin Eberhard said that the company sent letters out to the company’s customers last week informing them of the decisions. As he describes in his post, it was not one or two large additions but a long list of small items, all of which added up to the additional mass.

Maybe I was a bit naive expecting to hold the line on mass. Those of us at Tesla Motors who have a long automotive experience say that fixes to problems discovered [at] this stage of the program always adds mass.

The upside of all this is that the Tesla Roadster will be a much more reliable car for having added this mass.

At more than 200 miles, the Tesla Roadster will still have the highest range of any production EV in history by a large margin, and we will continue working hard to deliver even better range in the coming months.

      

Eberhard said that the company is holding to a floor of a 200-mile range, and striving for upward revisions. The target for acceleration remains the same, because improvements in the drivetrain have offset the additional weight.

April 18, 2007 in Electric (Battery) | Permalink | Comments (25) | TrackBack (0)

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I hope Tesla can hold the line, like they claim. But as the roadster is their first product they're for some rude awakenings like this one.

This was exactly what I expected. With luck a second model later on might hit 250 again. The question now is what other sur[tises lurk ahead. Its quite common for these things to pop up at every stage and its the reason many said wait till its on the road. By then it will be a very differebt car.. they always change alot.

200 miles versus 250 miles is still just fine I would think.

The addition of several hundred pounds is the tough item to swallow. Colin Chapman just turned in his grave. Acceleration may be the same, but this type of car is begging for corners not straights...and "adding lightness" is the best way to improve your cornering abilities.

any range above 150 miles is great, i still want one

Yes, I want one too...but who knows what other type of "bad" news Tesla will come out with before the real launch of the car.

FS

does any one know the cost of a new battery pack today and what would the cost be in 5 years

Looks as if Tesla is learning what Detroit (and Japan and Germany for that matter) already know, in that its not easy to deliver claims made before the final design. Thats why the major automakers show restraint, and because of that are chastised for appearing to drag their feet.

But if GM announced these sort of "adjustments" in an offering of theirs, they would be soundly beat up on. I guess the playing field is still not level.

But I do feel the future of our transportation is EV's of this type, and that Tesla should be applauded for their offering. I just wish their offering would be for us regualr Joes, and not the Jay Lenos and George Clooneys of this world.

On the Tesla site there is a video of what looks like the car running on a very large snow packed parking lot. The traction looks excellent. Just that video would make anyone that drives in those conditions want one.

Most likely hey had to beef up the crash frame and the frame around the battery. On top of that ill bet many parts simply were too weak and showed too much wear or stress in testing. Even something as simple as making the seats stay in place better in a crash could add 30 lb.

Telsa:Why not play it safe? NANOSAFE that is.
Dr Gotcher's has the cure.

SJC: The large parking lot is a frozen lake in Arvidsjaur, Sweden.
Nanosafe has half the energy density and is too expensive. But economies of scale may change that...

Half the energy density, but you can cycle from 0-100%, rather than 20-90%, so the overall difference in available energy density isn't that great (50 units vs 70 units).

Also, the A123 and Altair cells are currently designed for power, not energy. With thicker electrodes and compromise on power they could probably creep up to 150 Wh/kg. I heard a rumour that A123 have a high energy battery on the way.

I cringed when I saw the headline for this article, but after reading it, I am little more at ease. This is definitely a sizeable decrease, but not enough to sink their boat in my opinion.

Mark A had a good point in that we are all quick to jump on the bandwagon when the big Automkers have to make concessions due to unforeseeables. We say they are dragging their feet, or they're in cahootz with big oil, or they have the technology already and don't want to use it, etc. etc. This should be a good lesson here for many of us, in that it is an extremely difficult proposition to build a vehicle in this day and age, that satisfies all of the needs and requirements of the masses. It's laughable to me how easy many here make the business of building cars sound in their posts. It is far from easy, and I think Tesla is seeing that now first hand. I sincerely hope Tesla as well as GM and others succeed in their EV endeavors. I guess things like the range decrease suprise have to be expected as growing pains.

"But economies of scale may change that..."?
Lithium batteries are already one of the most prolific batteries on the earth. Virtually EVERY portable electronic device and power tool now has Li-Ion batteries.
Yet the economies of scale of how Lithium is mined or extracted from brine pools will not change....there is only so much of it.

We already have the economy of scale to lower Li pricing and it's supply and demand in effect. Li, just like fuel cells and other esoteric technology, won't be affordable for a long time.

Lith: re economies of scale: the Swede was referring to the Altair battery which is definitely not produces in any kind of quantity. I also recall (can't find the links) that there has been progress on methods of cheaper Lithium extraction from sea water. It's still very possible that the future my belong to somthing like the firefly battery or the MIT carbon nanotech ultracap.

Swede,

Thanks for the information. I thought it might be a frozen lake, but I could not figure where one would be close enough to the company.

With the independant motors, traction and stability control do not seem to be a problem on a frozen lake. Some would say that they do not drive on frozen lakes, but they may drive on frozen streets and this car looks like it handles frozen surfaces very well.

If ya bash GM ya gotta bash Telsa. Some how I just bet that when the vehicle finally hits the street it'll be under 200 after all!! Especially after the typical lead footed gear heads that buy it and drive it with their foot glued to the floor. Good luck to Telsa. I'm sure they'll do just fine cause it still looks like a tricked out, pocket rocket ride!!

There is only one reason the Tesla has had to make these design changes and lower the range - Bob Lutz made 'em do it.

Mark A - when the first PCs arrived in 1983 they cost $4-5,000.00 each; business, Jay Leno, George Clooney and a bunch of other unnecessarily lucky SOBs bought 'em - proving the market and driving production costs down. A fully loaded PC costs about 5 bills these days. Gotta hate those guys.

You gotta bash GM. Although Tesla had to readjust their claims for distance, GM has NO distance to claim. How can you bash Tesla when they are bringing a product to market. GM still has no product. No even a working prototype! C'mon people GM sucks. They are full of BS. If GM would just say that they will bring an EV to market although the batteries are expected to last only 6-7 years, they could, by then, have found a better battery. You can't even claim you're green if you don't put anything to market. Oh by the way, how many Hummers are still going on the streets?

One way to solve the range problem:

use A123 battery having much higher power output than regular Li-ion battery, allowing reduction of battery size to less than 1/3, thereby saving a lot of weight and space and cost. 10kwh A123 battery ought to provide a range of ~up to 40 miles, enough for daily commute, with proven high durability.
Instead of 0-60mph in 4 seconds, 2 more seats could be added to the back of the front seats, greatly improving the car's utility.

Then, drop in a 15kwh genset using lightweight jetski engine & high-speed generator, weighing not much above 100-150 lbs for the entire package, for range extension with quick fillup with gasoline for the occasional need to exceed to 40 mi electrical range. Problem solved.

Tesla will likely have more adjustments to make on their specs before the vehicle is on the streets, but after that major hurdle is achieved, just the "tweaking" design process will result in improvements that will likely exceed the original specs, even without major innovations like wheel motors or large format Li-Ion batteries. Remember this is new technology, check out the first ICE vehicles put on the road and how rapidly they improved in capability.

The argument that Li-Ion cells are already mass produced so vehicle batteries are already at rock bottom price is utter nonsense. Large format batteries are an entirely different animal, and are not produced in anywhere near automotive volumes as yet. You might as well say that a Lead-acid storage battery at $60 / kwh is impossible because small format lead-acid batteries run about $1500 / kwh.

The price and supply of lithium has little to do with Li-Ion battery cost, the amount of lithium carbonate in a Li-Ion battery is from 220-1400g / kwh which @ <$2.50 per lb is like $1 to $3 for a kwh of battery, if only we could get Li-Ion for $10 / kwh rather than $600 / kwh, it would be wonderful. Here’s a good commentary by Wayne Brown on the availability of Lithium:

“…First, I was erroneously using US tons vs. metric tonnes. I checked the actual USGS report & like you the USGS is using metric tonnes so, I apologize for that. I went ahead & ran just the numbers from ANL & the USGS. ANL pretty much sticks with 35kWh as being the average EV Battery size in the article so, I will use that rather than your 32.4 kWh size which overall, should deplete the world reserves faster & provide support for the point you are making in your article being featured here at EV World.
One very important thing we need to figure out though is why the Argonne paper thinks world supply is not a problem. Let’s take a good close look at their numbers & see why.
USGS (2000) says USA used 2,800 tonne in 1999 & that was enough to make 290,000 EVs or 6,000,000 HEVs.
2,800 tonnes = 2,800,000 kg
290,000 EVs X 35 kWh each = 10,150,000 kWh
2,800,000 kg / 10,150,000 kWh = 0.276kg/kWh or 276 g/kWh
276 g/kWh is much closer to R Smith’s final analysis above where he comes up with 250 g/kWh than 1,400 kg/kWh in the above article.
Argonne paper says world reserves exceed 12,000,000 tonne of lithium. Let’s just say there are only 12 million tonne.
12,000,000 tonne = 12,000,000,000 kg
12,000,000,000 kg of lithium / 0.276 kg/kWh = 43,500,000,000 units of lithium available to make 1 kWh each.
43,500,000,000 / 35 kWh per EV = 1,242,857,143 EVs or 1.2 Billion EV.
43,500,000,000 / 9 kWh per PHEV = 4,833,333,333 PHEVs or 4.8 Billion PHEV.
43,500,000,000 / 1.7 kWh per HEV = 25,588,235,294 or 25.6 Billion HEV. (Current Prius HEV has 1.3kWh vs. 1.7kWh shown here)
Just for the fun of it, let’s do the Prius….
43,5000,000,000 / 1.3 kWh per Prius HEV = 33,461,538,462 or 33.5 Billion Prius HEV
The ANL article very clearly states when referencing the world lithium supply; “Therefore, long-term supply should not be a major concern.” …”

If GM was really serious about the Volt, they could easily produce it as a standard series hybrid, with a 5 kwh battery pack, which would be quite sufficient for this vehicle, and could be made in NiMH like the Prius, just 4 times the size of the Prius' battery pack. The battery pack would be very lightly used since only about 1 kwh is needed to absorb and supply the normal acceleration & hill climbing energy, the other 4 kwh would be needed occasionally for hill climbing in the mountains and passing at high speed. Even in NiMH the battery would last in the range of 1 million km's like the Prius' has and would cost about $1100. When the Li-Ion batteries are ready for full scale production, the plug-in series HEV version of the Volt would be a trivial upgrade, actually could be even be made as a customer installed option. GM touts their so-called E-Flex architecture but doesn’t use it. Now why would that be.

Should be obvious. GM hates profits.

They need to make a 150MPG version for less than $50,000.

A car like that would sell 500,000 units every year.

GM loves profits, or at least their shareholders do. They just can not figure a way to make fat profits off of expensive large SUVs that fewer people want to buy.

This “Tesla” car and company is a joke - or worse.

They are using standard consumer item Lithium Cobaltite cathode 18650 cells. So these are the most widely available and mass produced cells avalable - and they are totally unsuitable for use in a motor vehicle. Never mind the standard inbuilt short circuit protection Mr Eberhard - that hasn’t stopped numerous fires with laptop batteries of only 96Wh capacity maximum. 56,000Wh capacity in this car - it is a DISASTER waiting to happen.

When you add on the over hyped claims on the website about rapid recharging at home (not possible from their figures) and the outright lie that gasoline cars need servicing every 3,000 - 5,000 miles - their credibility rapidly tends to Zero.

How dare you appropriate the name of the greatest electrical engineer the world has ever seen - plagiarism in the extreme.

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