[motorcyclistonline] - Battery Technology vs. Gas Engines: Can They Compete In Racing

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The Mission R looked the part of a competitive racebike, but even cutting-edge battery technology is no match for gas engines.




The title of the ’60s-era TV show Mission: Impossible was, of course, ironic. The mission always turned out to be possible, at least for the heroic protagonists. That hasn’t been the case for Mission Motors, maker of the Mission R electric superbike. The company recently closed its doors following two failed investment deals in just six months.

I started working with Mission as a contractor in 2009, designing the Mission R concept then acting as lead designer for chassis and powertrain development. The first prototype was completed in early 2011, followed by a very successful race debut at the Laguna Seca USGP where the Mission R, ridden by Steve Rapp, beat a field that included the leading entrants in the European electric bike championship by a 40-second margin.

"There’s no question an electric motor can make MotoGP level power and do so with far less waste."

Shortly afterward, Mission Motors dropped motorcycle development completely to focus instead on the then-burgeoning automotive electric field. That field is incredibly tough, and a breakthrough for Mission never happened. The company returned to motorcycle development in 2013. We started design work on an updated version of the Mission R in 2014, but early this year we were told that the project wouldn’t go forward. Mission: impossible?

What, if anything, does Mission’s failure say about the future potential for high-performance electric motorcycles? Just what are the possibilities? To answer that question, I propose a very specific thought experiment: Could an electric motorcycle ever compete on equal terms with an internal-combustion MotoGP racer? In other words, what would it take to build a credible eMotoGP bike?

There’s no question an electric motor can make MotoGP level power and do so with far less waste. A factory MotoGP bike uses 20 liters of gasoline in a race, but 70 to 75 percent of that fuel energy is wasted, mostly as heat (an internal-combustion engine is only 25 to 30 percent efficient at turning fuel energy into motion). An electric motor is more than 90 percent efficient. For the purposes of our experiment, let’s call electric 3.5 times more efficient than ICE. That means that if the MotoGP bike uses 20 liters of fuel in a race, the eMotoGP would use about 5.7 liters of equivalent energy (20/3.5).

Converting 5.7 liters first to kilojoules then to kilowatt-hours (kWh), we find that 55 kWh of electrical energy are equal to 5.7 liters of fuel. The Mission R battery weighed just less than 20 pounds per kWh. Zero Motorcycle’s accessory “Power Tank” battery is listed at 2.8 kWh and 44 pounds—that’s 15.7 pounds per kWh, a significant improvement over six-year-old Mission technology. Let’s say our new eMotoGP racer could use a super-lightweight battery that weighed just 12 pounds per kWh. That would still add up to a battery weight of 660 pounds (12 multiplied by 55). Whoa!

The current MotoGP weight minimum is 348 pounds. An educated guess might put the combined weight of the engine/transmission, cooling system, exhaust, fuel system, etc., around 160 pounds. That leaves 188 pounds for the rolling chassis. The electric bike will need essentially the same rolling chassis, and the electronic motor/trans combination might weigh around 70 pounds. That leaves just 90 pounds for battery weight.

The 570-pound difference between a current-tech, 660-pound, 55-kWh battery and some yet-unknown technology could carry that same amount of energy in a 90-pound package is where our thought experiment ends for the time being. The battery would have to be improved in its power-to-weight ratio by a factor of more than seven. For now, at least, that’s clearly mission: impossible.

Outside of Grand Prix racing, of course, absolute equivalence with ICE vehicles isn’t necessary. What the eMotoGP thought experiment does show is a quick estimate of the distance separating the two technologies. Shortening that distance remains the challenge—one that I believe is possible, though it is definitely going to take some time.

Did you find this article interesting? Get more "Drawing the Line" HERE

James Parker designed his first original motorcycle in 1971; his most recent design is the Mission R electric superbike. In between, he worked on multiple other motorcycle projects, including 30 years spent evolving the RADD front suspension system used on the Yamaha GTS1000 and various other prototypes.




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