The group, which operates under the auspices of the United States Council for Automotive Research (USCAR), is trying to standardize development of components such as connectors and fuses, while Japanese automakers are charging toward separate designs.

"We knew that if we didn't move soon, we'd have chaos," said Norman Traub, technology integration manager for Delphi Automotive Systems (Troy, Mich.), speaking at the IEEE Workshop on Power Electronics in Transportation held Dec. 5-6. "We were worried that every automotive company would develop its own prototype solution. And once those prototypes went to tooling, no one would want to go back."

The group hopes to help the auto industry deal with the technical issues that go hand-in-hand with the adoption of 42-V systems. Safety and compatibility are key issues.

Engineers at the workshop expressed concerns over the safety of consumers who try to jump-start vehicles by connecting to cars that use 14-V systems. They want to ensure that cables and battery terminals are designed so that 42-V and 14-V vehicles can't be connected.

"Most of today's systems are protected against a 24-V jump start, but not a 42-V jump start," said Paul Nicastri, project leader for 42-V architecture and drive development for Ford Motor Co. (Dearborn, Mich.). "People who try to jump a 42-V system with their 14-V system will have problems."

Engineers also expressed concerns that Japanese automakers are developing 42-V systems that employ a threaded fastener, or battery post, that is unlikely to meet future standards. Some fear that the battery post would make it too easy for determined consumers to attach a jumper cable and mistakenly connect 42-V systems to 14-V systems. "We need to eliminate the post," Nicastri said. "If we leave something that people can attach to, we run the risk that someone will get hurt. These are high-voltage systems that can be lethal."

Japanese automakers are concerned over safety issues as well but plan to deal with the problem by surrounding the posts with plastic to prevent any such mistaken connections, speakers said. Ultimately, USCAR members said they expect Japanese automakers to comply with whatever standards are developed but believe those standards may not be available early enough for their initial 42-V products. "The Japanese automotive companies are not opposed to what we are doing," Nicastri said. "But our impression is that they need to have a product plan now. We're too late for them."

U.S. automakers expect the new working group to have a significant effect on global standardization, however, even if Japanese companies are not initially on board. Companies such as Aston Martin, Jaguar, Mazda, Mercedes-Benz, Mitsubishi, Opel and Volvo all have ties to U.S. companies, providing significant global muscle to a U.S.-based effort. "If we can get Ford, General Motors and DaimlerChrysler together, then we can will have a good chunk of the automotive world market agreeing on one standard," Nicastri said.

Vendor compliance needed

One of the USCAR effort's key goals is to ensure uniformity among the components. "We need to have a common jump-start system so that a GM vehicle can jump-start a Mercedes-Benz, or vice versa," said Anson Lee, engineering supervisor for advanced powertrain electronics at DaimlerChrysler Corp. (Auburn Hills, Mich.). Uniformity among components would also make servicing and diagnostics simpler, Lee said.

The USCAR group, which works in conjunction with the Massachusetts Institute of Technology (MIT)/Industry Consortium on Advanced Automotive Electrical/Electronic Components and Systems, was formed to have a more direct effect on vendors. "MIT, being a university, does not have a lot of pull with suppliers," Lee said. "But when the Big Three tell suppliers to do something, the suppliers listen because they see an opportunity for business."

If automakers can foster more cooperation among suppliers, they believe they can speed development of 42-V technology. "We need this effort to move along faster, especially on the supplier side," Lee said.

The working group said its first step is to cooperate with fuse manufacturers on the design of new fuses for 42-V systems. "A fuse is a trivial item," Lee said. "But right now, some fuses burn up during arcing and some don't. We want everyone to design parts that won't burn up."

The group also plans to work with suppliers of batteries, connectors, wires, relays, switches, fuse boxes and jump-start cables on the design of common products. USCAR intends to fund studies on arcing and on the effects of 42-V systems on aftermarket products, such as conversion vans and campers, as well.

USCAR's 42-V specification will include both text and drawings. The organization hopes to use its ties with standard bodies, such as the Society of Automotive Engineers, to have the specification written into an automotive standard. "If you want to create a global standard, then you have to have a means of feeding your specification to a standards organization," said Traub of Delphi Automotive.

Ultimately, U.S. automakers hope to create a worldwide standard and then begin producing single-voltage (as opposed to dual-voltage) 42-V architectures in vehicles before 2010. They are leaning toward adoption of 42-V systems because they believe such systems will enable them to deal with higher power needs of future vehicles more effectively, particularly those that incorporate steer-by-wire, brake-by-wire, integrated start-stop systems, heated seats and heated windshields. Most of those features cannot be successfully incorporated with today's 14-V systems, which work with 1- to 2-kilowatt generators.

Skeptical engineers

First, however, the group must convince the automotive community that 42-V is necessary and cost effective. Many engineers at the workshop remained skeptical about the concept and peppered speakers with questions about the systems.

"Give me three good reasons why we should even consider using a 42-V system," demanded one audience member. When panel members mentioned integrated start-stop capabilities and heated seats, some in the audience remained unconvinced.

Still, the working group plans to continue its efforts because it doesn't want the world's automakers all heading in divergent directions. "There are some main issues we need to standardize on," Nicastri said. "If we all take different positions on those issues, no one gets any utility."