Filed under: EV/Plug-in, Tesla Motors
Tesla Roadsters reportedly experience glitches during Euro test drives
Ever since Tesla Motors started letting outsiders actually drive the Roadster late last year the reviews of the over-the-road experience have been largely favorable. In recent months, Tesla has been taking the Roadster on a European tour trying to drum up sales on the continent. One of the people who drove the Roadster was Guido Reinking, editor of Automobilewoche. Reinking praised the performance saying "the car offered the emotional, heart-pounding ride of a street racer." However, he also highlighted powertrain and battery issues we haven't heard about before, aside from the well-documented transmission issues.
Of the three cars available for the test drive, one apparently didn't run at all, while a second reportedly emitted smoke from the battery compartment. Reinking uses these issues to highlight the problem of battery reliability and why the Roadster might not be ready for mass production. However, we checked with Tesla SVP of marketing Darryl Siry who was also on hand for these 16 days of media and prospective customer drives. According to Darryl, two of the three cars on hand were equipped with the new 1.5 drivetrain while the third had the 1.0 interim drivetrain. Siry tells us that the car that wouldn't go had a faulty parking pawl sensor. The parking pawl is essentially a locking mechanism for the transmission that keeps the car from rolling when the gear lever is in park just as it does on a conventional automatic. The sensor erroneously detected park being engaged and prevented the car from moving. Read on after the jump for more on the "smoky" battery.
[Source: Automotive News - sub. req'd]
Reinking was present only on the first of 16 consecutive days of drives. Another driver had taken out one of the drivetrain 1.5 cars. Siry responed to Reinking's description of the incident as follows:
One of the test drivers took one of our prototypes on the Autobahn and drive it at vMax with repetitive hard accelerations. As the car is designed to do, it gave several successive warnings that temperature levels in the motor and electronics were reaching high levels (we know this from the computer logs). Since the driver continued the top speed runs, the computer slowed the car down as it is designed to do to protect itself. After that reporter (I don't think it was you, but someone else who experienced this, but please correct me if I am wrong) reported to us that he thought he had seen smoke coming from the back of the car, we were, of course, concerned. Even though the smoke alarm in the battery pack had not detected smoke, we decided to check it out thoroughly. Tesla technicians removed the battery pack and inspected every aspect, finding nothing wrong with the battery pack. In fact, it performed flawlessly for dozens of other test drives over the next 2 weeks (Munich was day 1 of 16 days of straight media drives). I still don't know what might have caused the journalist to report smoke - perhaps something like a wet leaf came into contact with the very hot motor - but the safety systems and powertrain performed as expected. All things considered, not bad for a full speed run on the Autobahn for a car that was admittedly not designed for sustained top speed.This is the first battery related issue that we're aware with the Roadster. Although in this case there was apparently no issue with the battery pack, the fact that something like this could potentially happen gives some credence to the approach being taken by major automakers like GM, Toyota and Nissan. All of the established manufacturers are developing batteries specifically for automotive use with larger format cells that would use far simpler construction than the Tesla battery pack. Major automakers are also pursuing different types of battery chemistry that sacrifice some energy density in favor of additional safety margins.
In this case being reported by Reinking, he appears to have something of an initial bias against electric drive given his opening sentence, "I have to admit that I don't find it appealing to consider a future in which we'll all be driving electric cars." Perhaps he should have done a little more checking before writing his column.
Reader Comments (Page 1 of 1)
Serge 9:17AM (8/26/2008)
Smoke could have been coming from all that burned rubber ...
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GoodCheer 9:31AM (8/26/2008)
I neither want to excessively defend Tesla, nor totally lambast this column, but how can this be
"the first battery related issue that we're aware with the Roadster."
when
"in this case there was apparently no issue with the battery pack"?
So this was the first reported instance of the battery not having any problems? That is factually inaccurate.
Furthermore:
"the fact that something like this could potentially happen gives some credence to (...)"
Unless you're talking about journalists with anti-EV bias reporting battery failures where none exist, then I don't know what you mean by "like this".
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Doug 12:44PM (8/26/2008)
After reading this article, GoodCheer said exactly what I was going to say. Regardless of the truth, the juxtaposition of these sentences makes no logical sense. I'd suggest revising.
EVan 9:34AM (8/26/2008)
Negative press about technology spreads very quickly.
I would really hope that one journalist's assumption won't cause an army of naysayers to start rampantly posting all over the internet that the Tesla battery packed is faulty and doomed.
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Darryl 10:06AM (8/26/2008)
Sam - we tore the battery down and there were no issues with the battery, so I don't think you can say this is the first battery issue you are aware of. The reporter in this case was reporting hearsay from someone else who claims to have seen smoke. The hottest part of the drivetrain - by far - during sustained acceleration and high speed like you would see on the autobahn, is the motor, not the battery. It is very likely that something else caused smoke (or steam, as it was a rainy day) and the person was pre-disposed to think it was a battery issue. You've seen the packaging of the powertrain - it would be difficult to specify where you see smoke coming from. In addition, the battery pack is sealed, so if there was smoke from the pack it wouldn't likely even escape to the outside. Hard to say what the guy saw because we weren't out on the Autobahn with him so we only have his description to go on. Regardless, we took the battery out and opened it up and found nothing out of the ordinary.
Regarding your conclusions, I would only say that thermal management becomes more difficult, not easier, with larger format cells.
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stevefazek 7:02PM (8/26/2008)
Great car how many amps does the controller pull from the battery pack under full load?
andrichrose 11:20AM (8/26/2008)
In 2001 I bought one the then new "Ipod"s
about two months later my neihbour told me
that he had seen a repoprt on the BBC that
they were all failing due to battery problems ,
I am glad to report that the one I bought is
still working and with the original battery !
these people will find something wrong with
everything that does not conform to their
own mindset.
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why not the LS2LS7? 12:39PM (8/26/2008)
The pawl issue just shows how complex it is to make any car. You can try to write off the pawl as a minor thing, but if I can't drive my car to work, it's a pretty major thing.
My Saturn never had a mechanical failure that made it undriveable in the 8 years/82,000 miles I had it. My Audi has done the same in 9 years/98,500 miles (although it's had a lot of non-critical failures). The engineering required to pull something like this is huge, and difficult for a small company to accumulate rapidly.
This also makes people's claims that the automakers were trying to keep the electric car down because they're so simple they'd never need repairs and thus the automakers would be deprived of repair income look even more silly.
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jake 1:39PM (8/26/2008)
Saturn last had a recall for faulty airbag sensors in 2007 so it's not like faulty sensors are unheard of even in larger automakers. Since Tesla Motors source a lot of their normal parts from the same suppliers as larger automakers, of course they aren't immune from the same problems (I'm not implying that this parking prawl sensor is serious to the level of a recall if that's what it sounds like, esp given these are prototypes and not customer cars they are driving).
The "battery issue" didn't sound like it was the battery. Like the article said it's most likely steam from water or a wet leaf hitting the outside of the motor, given that they are all located in the same general area of the car.
Richard 3:38PM (8/26/2008)
I don't see how your comment is pertinent, aren't electric cars simpler? That's what the whole propaganda on EV is about...simpler systems. I would think the gasoline cars, with it's thousands of components would have a much harder time of being built reliably! Electric cars have been around a long long time, engineers know them like they know gasoline cars. It doesn't make sense.
I think, on the other hand, that the reporter was trying to sabotage this movement. His intentions were clear from the onset with his preface. He should be held responsible for creating arousal for non pertinence.
vfx 1:55PM (8/26/2008)
My hood will steam when rain hits it. A hot motor would certainly do the same.
Considering the trunk lid is one big piece there's no way of telling if the vapor coming out the sides is from water coming off the PEM, ESS or the motor/gearbox.
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Whopper 2:03PM (8/26/2008)
When performing an FMEA (Failure Mode Effect Analysis) study one of the key multipliers making a failure a major occurance is the useability of the product in spite of the failure. In the case of the parking pawl, the failure is Major because it renders the vehicle inop. The whole point of performing an FMEA is to identify and categorize potential failure modes and eliminate them if possible or reduce the impact if elimination is not possible.
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stevejust 7:39PM (8/26/2008)
I was reading on Macrumors.com the other day about the existence, or future existence of "silver-zinc" batteries that have a much higher energy density than lithium-ion batteries. It pains me to know that if there is a problem with the Tesla battery pack, by the time Tesla figures it out they might be contending with a brand new technology with a whole new set of issues.
But thankfully they're doing it. I'm glad someone is. How come ABG isn't talking about silver-zinc batteries for automotive applications yet?
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Chris M 9:15PM (8/31/2008)
Silver-zinc batteries have been around for a very long time, and have some excellent properties, such as good energy density and high charge cycle count. Unfortunately, they are also expensive due to the silver, costing much more per Kwh stored than LiIon or NiMH.
While the cost is far too high for EV usage, silver zinc batteries have been used for certain specialized applications where the advantages outweigh the high cost. GM once built an experimental prototype EV using silver zinc batteries, it performed well and had an excellent driving range, but was too costly to consider producing.
Paul Sallmen 5:38AM (8/27/2008)
stevejust said: "How come ABG isn't talking about silver-zinc batteries for automotive applications yet?"
The answer to your question: Silver. Have you checked the price of this precious metal lately? I imagine silver in batteries would be cost prohibitive.
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BlackbirdHighway 8:35AM (9/02/2008)
Silver-zinc batteries have lower energy density than the lithium ion batteries that Tesla is using now.
A new company, ZPower is claiming that their new silver-zinc batteries have much better energy density. The information on their website is not clear about whether they have addressed the other problems with silver-zinc: high cost and the use of mercury. The mercury is a really big problem, because it is a highly toxic environmental hazard and tends to make the batteries corrode and leak. If ZPower is still using mercury I doubt you will ever see those batteries used in a commercial electric vehicle.
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