Kreisel Introduces 2-Speed Auto Trans For Electric Cars

SEP 10 2018 BY MARK KANE 16

2-speed transmission in an electric car is a rare sight.

Kreisel Electric automated 2-speed transmission for electric mobility applications

From time to time, news about 2-speed transmissions for electric cars appears and we’ve seen several prototypes over the years. The main advantage of having more than a single-speed is fun… that it enables to have both – high acceleration at low speed and higher top speed (without oversizing the motor).

The efficiency also should improve a little, but there are drawbacks such as higher costs, probably lower reliability, need to switch gears sometimes (not that often as in ICE) and slightly higher weight.

Recently, Kreisel Electric presented its own automated 2-speed transmission for electric vehicles, developed in partnership with Sala Drive. The transmission finds its way in sports car conversion that does 0-100 km/h (62 mph) in 2.5 seconds, reaches more than 300 km/h (186 mph) top speed and, using 54 kWh, can go up to 350 km (218 miles) on a single charge.

Kreisel’s 2-speed transmission is production ready, according to the press release, and can be used with one or two motors, for rear-wheel, front-wheel or all-wheel-drive configurations. Input power and torque stands at 600 kW and 900 Nm, respectively.

Not only halo cars could benefit from such a system, as according to Kreisel, small and medium-sized transporters up to 3.5 tons or trucks and buses up to 15 tons also could be handled.

Kreisel Electric automated 2-speed transmission for electric mobility applications

More about the transmission:

“„We have set ourselves the demanding task of building an ultra-light, electric supercar based on a historic sports car as the ideal application for our transmission,“ says Markus Kreisel, CEO of Kreisel Electric. The challenge here is that there is nothing even remotely like a standard component available here, no matter where you look. „So we developed the essential components ourselves on the basis of our own requirements profile,“ Markus Kreisel continues.

For example, the automated 2-speed transmission not only had to be able to guarantee unique acceleration values and top speeds, but also act as a reliable link between a high-performance powertrain and a correspondingly powerful and lightweight battery, which was also specially developed for the vehicle. The result is at the same time an experience in itself and very impressive. The sports car, which was already on show at Techno Classica in Essen in April 2017, sprints from 0 to 100 km/h in around 2.5 seconds, achieving a top speed of above 300 km/h. And all this with a range that is not only impressive in the supercar category: with a single battery charge you can easily break the magic range limit of more than 350 km.

So what are the ingredients for the success of the Kreisel Electric 2-speed transmission? „An electric lube oil pump with integrated oil reservoir that self-enables on demand for maximum efficiency. Massively reduced drag losses due to a friction-optimized bearing arrangement. Electromechanical gear synchronization, which ensures the shortest torque interruptions through optimized torque and speed control of the electric drive during lightning-fast, 0.25-second gear shifts. In this way, any thermal impact by friction elements and possible wear effects on the shift components can be practically eliminated. A limited slip differential lock, which is also integrated, ensures uninterrupted torque transmission even in slippery road conditions. And last but not least, a modular interface that supports a wide range of applications for motor and transmission arrangements,“ explains Philipp Kreisel, who is also a CEO of Kreisel Electric. In a maximum expansion stage, e.g. through the use of more powerful electric motors, breathtaking output values of 600 kW and an input torque of up to 900 Nm can be managed in this way. Using innovative approaches to complete vehicle integration, the center of gravity of the lightweight sports vehicle was lowered even further to achieve optimum handling with a weight ratio of 37% (front): 63% (rear). There is also a great deal of intelligence, variability and flexibility in the entire setup. A large number of sensors continuously monitor all relevant components and combine the collected data in real time in a transmission control unit (TCU). The modular powertrain arrangements allow for 1 or 2 motors per axle just as easily as a single motor. And for applications that also require high torques, such as small and medium-sized transporters up to 3.5 tons or trucks and buses up to 15 tons, the automated 2-speed transmission can be easily be adapted to match.

All this is rounded off by the integration of the world’s leading battery solution from Kreisel Electric, with a nominal capacity of 54 kWh, which is exclusively used in the electric sports car. „Thanks to our patented technologies, unique thermal management and the laser-welding process of the battery packs, we are now able to offer the lightest battery with the highest energy density for the most diverse applications, whether mobile or stationary. This in turn results in unrivalled, fast charging times, long ranges and a long service life of our battery solutions,“ says Johann Kreisel, the third CEO in the Kreisel Electric group, completing the overall picture.”

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16 Comments on "Kreisel Introduces 2-Speed Auto Trans For Electric Cars"

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A simple hi low range would work wonders, low for city and hills hi for freeway driving, I know many of the transmission manufacturers say just a two speed could increase miles driven per charge by 20 percent or more!

I just wonder, how reliable are statements from a company that sees its business endangered?

They had a great time with ever more complex gearboxes to eke out just a tiny bit more km’s from a litre of fuel. But now these EV’s need no gearbox at all.

It will all be down to price and weight: If the weight of the gearbox is less than the weight of cells you save due to lower consumption, that’s one win. If the cost of the gearbox is less than the cost of the extra cells you’d need, that’s another win. The cost savings for electricity do not count for much, since people aren’t really good at factoring these variable, future costs.

You should look up the company 🙂

This was reported on here in 2015 where ZF transmissions reported a 20% inrease in miles driven per charge using just a 2 speed transmission and that was three years ago, multi speed trannies are coming hope sooner rather than later!
Currently driving my Leaf up the slightest hill feels like a 3400 pound car with a 20 h.p. motor!

They could put their engineering time to develop better batteries instead, there is much more to gain there.

There is a good reason that no modern production EV has a transmission; that they all use a fixed ratio reduction gearset.

Those who have followed the history of EVs since 2008 or before, will remember Tesla’s woes with trying and failing — twice! — to get a supplier for a reliable two-speed transmission for the original Roadster.

That’s not to say it’s impossible to build one which will last, but it’s obviously quite an engineering challenge. We’ll need to wait to see how well Kreisel’s transmissions perform in service before pronouncing them a success.

Tesla’s failure was 10 years ago. I suspect companies with transmission experience can build multi speed transmissions that would work with an EV and handle the torque load. The question is, At what cost?

It can certainly be done, I just don’t think it is worth the trade-offs. Transmissions are expensive, complex, and extremely difficult/expensive to fix when the break. Just get rid of it. The lack of any kind of clutch system is one of the things that makes EVs so much more reliable than ICE cars.

You present a compelling argument. Thanks for your comments!

Maybe there are some niche applications. But I just really don’t see the added cost, complexity, and something that will eventually break down ever making transmissions worth putting in light-duty consumer cars.

Efficiency gains have been solved with all wheel drive.

You have one pair of wheel gear for torque and acceleration and the other one for range and speed.
You gain all wheel traction, regeneration and redundancy, add efficiency and reduce brake and tire wear with it.
Much better than a two speed gear box

Very impressive – BUT Kreisel are conspicuously silent/cagey on the question of price – especially of their battery packs.
It all looks like premium priced high-end market EV tech. Just too many EV startups out there wanting to serve the already spoilt-for-choice wealthy elite.
If any EV startup wants to be truly transformative / disruptive in 2018 – low prices and high production volumes are everything.
Kreisel seems to prefer the infinitely easier premium/prestige, rich-niche route.
Am I right, Arnie ?
Paul G

Beside several other single show projects for car conversions, Kreisel were replacing an E-Golf (24KWh) pouch pack with their 18650 cell pack (55KWh) and offered their laser welding and submerge of those cell assemblies into a isolating coolant to VW for licensing, but VW declined. Kreisel opened a China office and was hoping to find pack assemblers for low cost mass license production, without success. So all those awards for highest volume & weight energy density they grabbed in Austria and Germany were not leading to mass production.

Now Kreisel Electric is mainly focused on fleet conversions (20 units and up) from ICE to EV for commercial fleet operators. They also selling their version of a Powerwall. End customers with single car conversions or single ‘make to order’ battery packs are not served. The Porsche 910 replica production selling at 1 million Euro a piece is just some lighthouse project.

I hope the figure it out for the e Golf battery they developed. I’d live to be able to put in the 55 kWh (or better) battery with 100kW DCFC in my e Golf in a few years after I pass the 100k warranty.

What is the gain in efficiency?

What is the gain of torque?

Does it include a differential?

Are the half shafts equal length?

It looks to be pretty large relative to the motor(s). If you have two motors, then why not just use one per wheel, and gain torque vectoring?

As of late are most DIY builds dropping the transmission? My 2002 Chevy blazer is RWD and Automatic. DUMB NOOB questions for 2019… but if I can go w/o transmission (for simplicity and weight reduction) possible to move the electric motor under the truck closer to the rear axel? And if I’m also hoping to do without Air and going to Rack and Pinion and electric braking might I have enough space under the hood for all components and Lithium batteries? Also can I consider lifting the body to make more space under and inside the engine bay? I’m good with 70mph, 70 mile range and charging in 7 hours.