Exclusive Interview With Honda’s Chief Engineer – Part 1: Ultracapacitors

Editor’s Note: This is the part one of an interview Tetsuya Yokoyama recently had the opportunity to conduct with Honda R&D Chief Engineer, Mr. Yamamoto at Eco-Products 2008 in Tokyo, Japan. Mr. Yamamoto is greatly involved in the development of Honda’s hybrid technology including the upcoming 2009 Insight.

Honda Insight Concept FrontI’d like to thank all the readers who responded to my previous article with questions I could pose to Mr. Yamamoto. I’d also like to thank InsightCentral.net members for responding to that article too! I really appreciate your input, and apologize for taking so long to write this article.

After talking a bit about Green Options Media, Gas 2.0 and Insight Central, the very first question I asked him was about the possibility of using an ultracapacitor in a future Honda hybrid. More than ten years ago, the Integrated Motor Assist (IMA) power train was first introduced with the J-VX concept and was originally developed with an ultracapacitor instead of NiMH batteries.

Mr. Yamamoto explained that Honda engineers have researched ultracapacitor technology in the past but that the technology, although promising, is still too new and has several challenges to overcome. In the end, Honda decided to go with NiMH batteries on the first generation of Insight in consideration of mass production and quality control.


Honda has continued to do research into ultracapacitors and the FCX (pre-Clarity model) used to have it in production models. He pointed out that the ultracapacitor has great characteristics, such as low internal resistance and high output power, and therefore, the technology is still the subject of Honda’s research and development even though further advancement is needed for practical application. Considering various factors and the recent advancement of lithium ion and NiMH battery technology, relatively speaking, the ultracapacitor technology has taken a backburner at the moment, he added.

I have much more information to share from this interview, and will post it as I have time to translate and write it. Stay tuned to Gas 2.0 for more…

Honda Insight Concept Rear

Honda Insight Concept, five minutes before the opening of the final day at Eco-Products 2008.

Honda Insight, Mr Yamamoto, Me and Friends of Peanuts at Eco-Products 2008

Honda Insight Concept, Mr. Yamamoto, Me and Friends of Peanuts at Eco-Products 2008.

* Please note that my interview with Mr. Yamamoto was conducted in Japanese and this post represents my best effort at translating his Japanese into English. Keep in mind that some of my translation may express a slightly different meaning from what Mr. Yamamoto intended to explain, and I may have a misunderstanding on some technical topics because I have no technical education in this subject. Please feel free to point out if you find an incorrect description. I do appreciate it because my intention of writing this article is to share correct information on this interesting topic.

* I brought all questions I got from readers, and basically asked him these questions as much as possible. Please understand I could not ask all questions because of a limited interview time.

Image Credits: M. Koguchi

Tetsuya Yokoyama

Originally from Kanazawa, Japan, Tetsuya graduated with honors and distinction in major from the University of California, Santa Barbara in Environmental Studies, and also completed a Global Operations Management certification program at the University of California, Irvine. He loves biking and playing soccer, and very interested in all kinds of green products and services. He used to drive his beloved hybrid car, Honda Insight in Southern California. Tetsuya currently writes about green matters from Tokyo, Japan. He hopes to make our planet a little more human and environmentally friendly place by spreading and sharing green stories.