Japan Pioneers Two Good Ideas: Fast Charging and Battery Swapping

REYKJAVIK, ICELAND -â€" In an interesting twist, Japanese companies are leading the way on two diametrically opposed EV charging techniques, 480-volt DC fast charging and battery swapping. One of them is likely to fall by the wayside, but there's no harm in pioneering both.

Fast-charging advocates say that if you can fully charge a battery electric car in 30 minutes, then you may not need swap stations -- whose primary virtue is speed (automated, in the Better Place model demonstrated in Tokyo, it takes less than a minute. The program was so successful, it was extended). But 30 minutes is still a long time compared to the three to five minutes we spend at gas station pumps. What do you do at a gas station for half an hour?

My own take is that fast charging may triumph for consumer cars, but battery swapping could win out for fleets, which could swap at central depots and use standardized batteries. That's why Better Place's Tokyo taxi program makes eminent sense. It's far more challenging to keep a huge stock of incompatible batteries on hand to swap whatever comes by at highway stations.

Ichiro Fukue, senior executive vice president at Mitsubishi Heavy Industries, said at the Driving Sustainability 2010 conference in Iceland last week that the company will roll out a test fleet of EV buses in Kyoto next February, followed by mass production in 2013.

The 65-person buses have 160-kilowatt motors, and 60-kilowatt-hour lithium-ion batteries. They have a range of just 16 miles, followed by a quick swap at the battery station. Fukue said that swapping batteries makes sense for bus fleets, because even half an hour is too long to keep the buses out of service.

There are some big advantages to zero-emission buses: Mitsubishi's concept designs included the buses arriving inside the terminal like trains, instead of outside it as polluting buses normally do. In the illustration, a string quartet was providing music. The concept also included using the buses to send power back into the office tower to which they're connected.

Mitsubishi also produces the I-MiEV battery car, which is making inroads into the Japanese market. Fukue said the company's business model includes the concept of "co-ownership" of expensive lithium-ion battery packs, with the cost spread across two consecutive owners before a resale to utilities for stationary power. Fukue didn't explain how the "two-owner" concept would work, but it might be predictive of a secondary market for used batteries comparable to the way people save money today by buying used cars.

The i-MiEV doesn't swap batteries, but it is fully compatible with the CHAdeMO fast charging standard created by Tokyo Electric Power (TEPCO). The CHAdeMO standard was first out of the gate, and governments and trade associations in Europe and the U.S. are haggling over whether to adopt it or develop their own version. If they do develop their own protocol, the "not invented here" principle will be at work, since CHAdeMO is very workable internationally.

In Iceland, Hiroaki Takatsu, executive director of TEPCO, said the company was moved to act on EVs by the stark fact that it produces 10 percent of the carbon emissions in Japan. Takatsu said the company has put in place a dramatic emissions reduction target of .33 kilograms of carbon dioxide per generated kilowatt hour of electricity by 2020. "Achieving a low CO2 target from the current fuel mix is very challenging," he said. "It's hard to get there on the supply side, so we're looking more on the demand side."

EVs are an answer, and CHAdeMO makes them work better, Takatsu said. "Your charging will be complete while you have tea," he said. Takatsu also chided the lack of standardization among charging companies, which included the use of incompatible conductive and inductive plugs on an earlier generation of U.S. EVs. "It wasn't useful for EV drivers, and it did not remove range anxiety," he said.

CHAdeMO has won some prominent partners, including Think (the Norwegian EV maker), Bosch, utilities in Italy and Ireland, and charging companies Aker Wade (which makes fast chargers for forklifts and airport vehicles) and AeroVironment. Takatsu said that modern batteries were in some cases "overdesigned," and there are no cases I Japan of packs being damaged by fast charging.

There has been some speculation that Mitsubishi was working with Better Place on battery swapping, but Takatsu denied it in Iceland.

Takatsu said that 50-kilowatt DC fast chargers could cost $25,000, which is half of the figure I've seen quoted from western companies.

The TEPCO standard has gotten off to a fast start. There are 153 DC fast chargers in TEPCO's service area, and 254 in Japan. The company is gaining valuable fast charging experience, and it has already reached some interesting conclusions. According to TEPCO, many EV drivers have depended less on public fast charging after they got over their "range anxiety." Once drivers realize they can make it home on the charge they got overnight, they're less likely to stop at a public station for a top-off. That could happen in the U.S., too, especially since public charging is likely to be more expensive than charging at home.

Both fast charging and battery swapping have roles to play, and those roles will become clear very quickly now that the cars are finally rolling out.

Related:

• Better Place's Tokyo Battery Swap: A Test to Show the World
• Better Place Extends Tokyo Battery Program, and Still Lacks an Automaker Partner