Germany Automakers' Hybrid Efforts Plagued by Technical Problems

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http://www.spiegel.de/international/spiegel/0,1518,472189,00.html



Germany Automakers' Hybrid Efforts Plagued by Technical Problems


By Christian Wüst

German automakers will introduce hybrid cars into the market later than planned. Carmakers underestimated the difficulty of developing the sophisticated, environmentally friendly technology.

The first defeat was bad enough. It amounted to a collective recognition by executives at German car companies that they had misjudged the situation. More than two years ago they made a decision, a first in the history of the German automotive industry, to emulate the Japanese and build hybrid automobiles.

The issue could no longer be ignored. The savings that can be achieved with the hybrid gasoline and electric engine are simply too substantial. Porsche CEO Wendelin Wiedeking experienced the second setback more directly. Wiedeking wanted the best hybrid engine for his company's gas-guzzling Cayenne SUV, and he wanted it as quickly as possible. His first move was to contact Toyota, the pioneer in hybrid technology.

The Japanese told Wiedeking that they could help him, but only by providing the full package -- in other words, the platform for the entire vehicle. The Japanese insisted that merely buying the individual components, as Wiedeking had envisioned, made no sense. The Asians politely advised the Porsche boss not to underestimate the complexity of hybrid engines. Wiedeking's talks with Toyota quickly came to an end.

Today Porsche's engineers know that the Toyota executives were by no means trying to make fools of them two years ago. The engineers discovered first hand just how sincere the Japanese had actually been when they set out to develop, in a joint effort with Volkswagen, a hybrid engine at Volkswagen's research center in the town of Isenbüttel near VW's Wolfsburg headquarters. But the project failed to progress as smoothly as the Germans had expected.

German hybrids by "end of decade"

The original plan was to introduce hybrid versions of three SUVs: the VW Touareg, Audi Q7 and Porsche Cayenne. But that deadline has now proved to be unrealistic. VW will unveil its first hybrids next year, but they will not be available for sale by then. Wolfgang Dürheimer, who heads the research and development division at Porsche, has revised the predicted rollout to a vague-sounding "end of the decade."

The company has barely managed to come up with prototypes of the first construction stage, which suggests that actual production would not begin for at least another two years. System supplier Bosch has developed a power supply unit that can handle high-voltage current of up to 300 ampere, but it takes up most of the trunk. "Of course, it still leaves much to be desired," says Dürheimer, promising that the size of the wiring system will soon be reduced.

The biggest problem lies in the relatively crude drive train the German engineers have chosen. While Toyota uses a complicated engine-gearbox combination with two electric power units, the VW/Porsche system features only one electric motor between the internal combustion engine and the gearbox. This motor has to serve multiple purposes: acting as a generator and supplying the braking energy to the battery, powering the vehicle on its own when only the electric motor is operating and serving as a starter for the combustion engine. These processes are controlled by two automatic clutches.

Unappealing hiccups
The most difficult part of the system is achieving a smooth transition from pure electric mode to combined combustion engine and electric mode. The prototypes are still plagued by unappealing hiccups.

Eliminating this weakness could become a matter of destiny for this type of hybrid, to which the Volkswagen Group has fully committed itself. The system will also be offered for the Golf class, but a little farther down the road, because hybrid development at VW was put on ice until Martin Winterkorn took the helm as the company's new CEO.

DaimlerChrysler and BMW are leery of the more economical solution and, in a joint effort with General Motors in the United States, are developing a more complex full hybrid system. Though based on the Toyota model, the system's more ambitious mechanics will allow it achieve even lower fuel consumption.

But the gear train is extremely costly and will initially be used only in heavy SUVs.

The two competing German companies have also joined forces to create hybrid engines for their flagship 7 series (BMW) and S class (Mercedes). At first only a "mild" hybrid drive will be used in which the electric motor merely supports the combustion engine and never propels the vehicle on its own.

This less costly system produces almost the same reduction in consumption as a full hybrid, in which a lack of battery capacity prevents the more powerful electric motor from ever operating at its full potential. The only argument against the "hybrid-lite" solution stems from marketing experience. Honda has been selling cars based on this system for years, and yet the company is not perceived as a true hybrid manufacturer. The important factor missing in cars that are incapable of running purely on electric power? The wow effect.

But Mercedes does plan to attract attention in the industry with a breakthrough in battery technology. In early 2009, the mild hybrid S class will be one of the world's first mass-production automobiles equipped with lithium ion batteries.

This extremely efficient type of battery is already being used successfully to power mobile phones, but it is difficult to control at sizes required for cars. Even the Japanese are nervous about using lithium ion batteries. The supplier of the batteries for the S class will be French battery maker Saft, a company with experience mainly in the aerospace and defense industries.

Meanwhile Varta, a Hanover-based institution in the battery-making business, is trying desperately to keep up. Even German carmakers are buying nickel metal hydride batteries, currently the standard in hybrid automobiles, elsewhere. VW buys its batteries in Japan, from Honda supplier Sanyo.
 

TDIMeister

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Just have a fuel spill and ignition and see what happens... what's your point?

I'm typing this post in one of two laptops in my possesion with lithium batteries and I'm still fine.
 

weedeater

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And why did those computer companies have a massive recall of lithium computer batteries last year? Because they catch on fire, VERY robustly, and you can't put them out. Well, at least until they melt through your desk.

Even the Japanese are nervous about using lithium ion batteries.
And for a danged good reason
 

Kiwi_ME

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A reasonably technically-oriented article.

The most difficult part of the system is achieving a smooth transition from pure electric mode to combined combustion engine and electric mode.
I guess they didn't appreciate the complex speed/torque pattern that results when an engine is started. Trying to do it with clutches while on the move? - good luck! The servo actuator controlling a clutch could not be nearly as fast as the response from a servo motor, to say nothing of having to compensate for differing friction characteristcs due to wear and temperature. Without a fast response there is no way to have a seamless transition.

This smells like management trying to prove a point to a competitor (Toyota) without understanding the technical implications of taking a different path. It should have dawned on them that Toyota spent a lot of time and money on the Prius and the outcome was no accident.
 

weedeater

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This startup jolt was one of the things that turned me off when test driving the Honda Accord Hybrid.
 

oilhammer

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There are just too many to list....
People complained about that on the RX400h, too. But at least they couldn't complain about the herky-jerky shifts like the RX330 has. The RX400h's CVT is silky smooth.
 

AutoDiesel

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weedeater said:
And why did those computer companies have a massive recall of lithium computer batteries last year? Because they catch on fire, VERY robustly, and you can't put them out. Well, at least until they melt through your desk.



And for a danged good reason

Because they didn't use the most up-to-date safest technology?

Do a little research about lithium-ion batteries using phosphate based
cathodes instead of cobalt-oxide bases cathodes. Or even lithium-polymer with gel-type electrolyte.

Technology advances on as usual.
 

03_01_TDI

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The biggest problem lies in the relatively crude drive train the German engineers have chosen. While Toyota uses a complicated engine-gearbox combination with two electric power units, the VW/Porsche
system features only one electric motor between the internal combustion engine and the gearbox. This motor has to serve multiple purposes: acting as a generator and supplying the braking energy to the battery, powering the vehicle on its own when only the electric motor is operating and serving as a starter for the combustion engine.

Crude german drivetrain? Maybe the germans should look at how Honda's system works. Very simple idea. Use the Flywhee as the rotor/stator and build hybrid aroung that.
 

oilhammer

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There are just too many to list....
Some interesting observations:

Dr. Ferdinand Porsche himself designed and built the Porsche-Loehner "Mixt", which was a gasoline/electric hybrid of sorts back in the '20s I believe. I guess Porsche forgot about their cutting edge heritage.

The Cayenne/T'reg/Q7 use a pretty much out-of-the-box Aisin 6 speed automatic. Aisin is partly owned by Toyota, and also provides all Toyota transmissions, including the rear-drive/AWD longitudinally mounted 4, 5, 6 speed as well as MG (motor-generator) integrated versions of the 6 speed box for the hybrid GS400h and LS600h. So using something like that and integrating it into the existing VAG/Porsche platform should not be that complex since Aisin already has one on the shelf.

Panasonic provides most of the rest of the bits, and although Toyota's control and integration of the hybrid system is very complex, the "meat and potatoes" of the setup is not all that complex, especially in the GS and LS. Just like the Japanese copied (and continue to copy) with their diesel technology (the "Bosch under license" tags are on Denso, Zexel, Diesel-kiki, etc. components) it would seem Bosch, Siemens, etc. could do the same, or just contract to Panasonic if need be. I know there are anti-trust laws that might come into play, and Panasonic has been bought into by Toyota for hybrid development.

And the nonsense about Toyota insisting on a "whole platform", not just tech? Hogwash! They supplied Ford with the hybrid tech for the Escape, which is in no way on an Toyota platform, as well as Nissan/Renault, and last I checked the Altima has no platform sharing with any Toyota product.

Or, team up with the Koreans (Hyundai) who have a knack for back engineering everyone else's tech and making in their own! Hyundai must talk to Bosch, as they use their crappy MAFs on their newer cars, I replace them all the time!:cool:
 

njkayaker

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oilhammer said:
Dr. Ferdinand Porsche himself designed and built the Porsche-Loehner "Mixt", which was a gasoline/electric hybrid of sorts back in the '20s I believe. I guess Porsche forgot about their cutting edge heritage.
What was "cutting edge" in the 1920s isn't likely to be cutting edge now. It's possible that the German's problem is that they are using this 1920s technology.

oilhammer said:
And the nonsense about Toyota insisting on a "whole platform", not just tech? Hogwash! They supplied Ford with the hybrid tech for the Escape, which is in no way on an Toyota platform, as well as Nissan/Renault, and last I checked the Altima has no platform sharing with any Toyota product.
I don't think Toyota is referring to the car body when talking about "platform" (that interpretation clearly makes no sense). Toyota is talking about the combination of ICE/electric engines/transmission/control. It also appears that Ford is not using Toyota techology but rather the technology they also developed was first patented by Toyota. Thus, Ford is (supposedly) paying Toyota to avoid patent infringement problems not buying technology.
 
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