Toyota Takes the Stealth Approach

Amid the race among automakers to introduce a more powerful but possibly risky kind of battery to reduce emissions, Toyota has already been quietly offering a green technology based on the lithium-ion battery in Japan.

Lithium-ion batteries are considered critical in developing ecological cars of the future. The batteries are widely used in laptops and other gadgets. But they still aren't common in cars except in experimental electric vehicles.

Worries about the safety of lithium-ion batteries, which overheated recently in laptops and cell phones, are a major obstacle to introducing them in cars.

But the lithium-ion battery has been part of an "intelligent package" for Toyota Motor Corp.'s Vitz subcompact since 2003 -- although the feature is available in extremely small numbers at about 10 vehicles a month.

Toyota now uses a different kind of battery called nickel-metal hydride battery in its gas-electric hybrid Prius.

Still, the commercially sold cars with Toyota's own lithium-ion batteries might be its best-kept secret.

It underlines how Toyota is quietly but surely collecting information about the battery's performance under road conditions among consumers.

Toyota Executive Vice President Masatami Takimoto said recently the company hasn't marketed the feature aggressively because battery supplies are limited and the company can't respond to massive demand.

But the feature is available at dealers, and consumers can get it if they ask for it.

"We don't tell everybody about it," Takimoto said. "But we already have our own lithium-ion battery."

The Vitz with the lithium-ion battery delivers better mileage at about 60 miles per gallon, in Japanese testing, compared with the regular Vitz at about 53 mpg, according to Toyota.

The Vitz lithium-ion battery sits below the passenger seat. The car also has a regular battery under the hood. The ignition starts by using the regular battery.

When the car goes into idling, as when the driver shifts to neutral or park at a stop light or in congested traffic, the engine stops automatically.

While the car is idling, the lithium-ion battery keeps providing electric power to the car's air conditioning, radio and other equipment.

When the driver's foot is lifted from the brake pedal, the engine restarts from idling, using the lithium-ion battery. The lithium-ion battery recharges automatically as the car gets driven.

A Vitz with the "intelligent" feature costs about $10,200, about $870 more than standard models.

Other automakers, including General Motors Corp. and Japanese rival Nissan Motor Co., are all working on lithium-ion battery technology for green cars expected in the next decade or so.

Source: [url=http://www.forbesautos.com/news/headlines/2007/november/ap110607-toyota-lithium-ion-battery.html]ForbesAutos[/url]