Trade Secrets

Motor, May 2008 by Cerullo, Bob

The world's transportation needs continue to grow, good news for automotive techs. But you'd better be flexible because many vehicles now being introduced dont have conventional propulsion systems.

I can't imagine a better endorsement for a car manufacturer than to have General Electric invest $4 million in the company. Generally, you don't think of GE as being involved in vehicle manufacturing. But there is a. logical connection. (More on that later.)

TH!NK is a Norwegian company that unveiled a new two-door all-electric car as well as a concept car at the Geneva Motor Show in early March. The THINK city and the THlNK Ox, the concept car, are both all-electric. The THINK city has a top speed of 65 mph and can travel about 120 miles before it needs recharging.

(Editor's Note: Actually, we first told you about the THINK city mini car in our March 2000 issue. It was supposed to come to the States "within the next two years," a separate brand of Ford Motor Co., to become Ford's environmentally responsible mobile division. To make a long story short, the car is still scheduled to be introduced here, although the company is no longer owned by Ford.)

The THINK people say they have 1400 vehicles already on Norwegian roads. Sjur Heglund, Sales Manager of THINK, told me the THINK city will be distributed in the Scandinavian region in 2008, in Great Britain in the beginning of 2009 and in the U.S. market in mid- or late 2009.

The THINK city is not a production car retrofitted with an all-electric power plant. It has been designed as an all-electric vehicle from the ground up. The main parts of the electric vehicle system are: a traction battery, drive train, motor, motor controls, vehicle controls, charger, DC-to-DC converter, reduction gear and high-voltage system. The traction battery module is located underneath the seats in a position the carmaker says provides the best protection for the battery. It also gives good distribution of the weight between the front and rear axles and provides the vehicle with a low center of gravity.

There are three battery options. THINK offers the Zebra sodium battery manufactured by MES-DEA. THINK is also cooperating with two suppliers of lithium-based battery systems. A123Systems supplies a lithium-based Nanophosphate system and EnerDel, Inc., supplies a lithium manganese battery system.

According to information obtained from THlNKs website, the Zebra sodium battery has high-energy density and provides long-range performance regardless of the ambient temperature. It's a "hot" battery, which means that the operating temperature is between 270° and 350°F. This option is ideal for regular and frequent usage patterns. Active materials in the battery are salt, nickel and iron. The hot materials are contained in a vacuum-sealed and insulated container. The Zebra battery operates efficiently in very hot and very cold climates.

The lithium-based systems operate at ambient temperatures and do not require the car to be plugged in when not in use.

On its website, the company states: "We will own the battery and take full responsibility for its performance. The customer will only pay a monthly mobility fee, which includes a full maintenance service agreement, carbon offset payments and in some countries, even all electricity used, and insurance. In other words, customers can drive with the peace of mind that everything is taken care of. We will continue to take responsibility for battery performance through the car's life span, and exchange the battery when necessary."

Historically, the weakness of electric vehicles has been the battery, but battery technology has advanced by leaps and bounds. Finding a battery that would provide a range practical for the average car buyer has been a major difficulty. In the case of the THINK city, the 120-mile range could work for the average commuter, whose drive to work is about 30 miles.

The relatively short 120-mile range (compared to hybrids) may soon be solved through the efforts of Dean Kamen, the inventor of the Insulin pump and the Segway personal transporter, now all the rage with police epartments and the idle rich. It seems Kamen has spent some $40 million developing Stirling engines. The Stirling heat engine can use virtually any fuel source to heat a sealed container containing a gas-hydrogen or helium, for example-that expands and contracts to drive a piston and produce electricity which, in the case of the THINK city, could be used to trickle-charge the battery and extend the range.

General Motors is reaching for the same electric vehicle market with its introduction at the North American International Auto Show of the Chevy Volt. The Volt is a batterypowered, four-passenger, extendedrange electric vehicle with 40 miles of driving range, with a gasoline/E85 FlexFuel on-board engine to create additional electricity to extend the range. The Å-Flex electric propulsion system allows driving past the 40-mile mark, at which time the system kicks in to provide electrical power until the battery can be recharged. Fuel economy could be over 100 miles per gallon. The Volt can be fully charged in six hours by simply plugging into a 110-volt outlet.