Honda FCX-V3

Automotive Industries,  Jan, 2001  by Gerry Kobe

• E-mail
• Print
• Link

Honda's third generation fuel cell vehicle shows many improvements and uncanny sophistication.

FCX-V3 uses the body of Honda's EV Plus electric vehicle. And because its V1 and V2 predecessors did the same, it helps illustrate the impressive advances the company has made. Specifically, the latest car has made improvements in three critical areas: packaging, ease-of-use and performance.

From a packaging standpoint, Honda's FCX is now a four-passenger vehicle instead of two. In the V1 and V2 versions of the car, the fuel cell system was packaged under the floor and extended to the trunk. A huge battery pack and CPU occupied the back seat area, and the engine bay was stuffed with a bully 49kW motor and an air compressor.

On the V3, the motor is 25 percent lighter, 21 percent smaller in diameter, three percent more efficient and packs a 60kW punch. Its compact size, combined with a smaller air compressor, allowed the CPU to move into the engine bay. The Ballard-supplied fuel cell stack shrank by 20 percent and is also higher in output (62kW), which provides enough power for Honda to replace the battery pack with an internally developed, compact, ultra capacitor. Lastly, a compressed hydrogen tank behind the rear seat replaces a bulky and heavy metal-hydride storage.

Going to compressed hydrogen contributed substantially to the second major improvement: ease-of-use. With the hydride storage tank in the V2, it was necessary to heat the system to get release of hydrogen. This forced a 10-minute start-up time before the car could be driven, compared to a 10-second start-up now.

Refueling is also down to about five minutes compared with the 20 minutes it took to refuel the V2's hydride tank. In addition, unlike a hydride, the compressed hydrogen tank does not require external cooling during the refueling sequence.

From a performance standpoint, the previous generation Honda FC cars used batteries to provide power assist when the fuel cell alone wasn't adequate and to reclaim energy during braking. But as energy output from today's fuel cells approaches the maximum needs of the motor, the need for a full battery pack is eliminated. So the V3 uses a Honda-developed ultra-capacitor instead.

Aside from the weight and volume savings, capacitors don't need voltage controllers, resulting in increased efficiency of the system. Also, capacitors have an instantaneous response rate and high current. And because it can charge much more rapidly than a battery, it can reclaim higher amounts of energy during braking. Honda claims that testing shows fuel efficiency and acceleration are both improved using a capacitor.

In addition to developing its own capacitor, Honda says it is developing its own fuel cells for the future as well. After praising Ballard for cutting edge technology and reliability, Honda R&D chief engineer Shiro Matsuo says it's not about Ballard, it's about Honda.

"Honda wants to control the driveability aspects of all of its vehicles," Matsuo explains. "Electric motors normally feel the same, but they can be made to feel better if they have a better power source, so we want to control that. Also, please remember what Honda does well and that is manufacture. Even if we could only match Ballard for efficiency, we think we can manufacture a fuel cell cheaper, faster and with higher quality."

Based on Honda's track record, there's no reason to doubt it.

COPYRIGHT 2001 Diesel & Gas Turbine Publications
COPYRIGHT 2008 Gale, Cengage Learning