Industry Nears Plug Standard for EVs

The auto industry is closing in on a standard for connectors that will be used to link full electric and other plug-in vehicles to the power grid, says an executive heading up an industry group chartered with developing the protocol.

The EV conductive charge coupler standard, known as SAE J1772, has been in the works for about two years, says Gery Kissel, engineering specialist-chargers and cord sets for General Motors Corp., who headed the industry committee to establish the standard.

Kissel delivered an update on industry standard activities at the recent SAE World Congress in Detroit.

The text of the final connector proposal now is being prepared and “we hope to have a ballot” this month, he says, adding the whole process should wrap up by summer.

The industry wants to set a standard for electrical connectors to ensure manufacturers don't have to tool up for a variety of devices all meant to do the same basic thing — get electricity from the grid to the vehicle — and consumers don't have to worry about changing interfaces every time they buy a new car.

In addition to GM, nine other auto makers are participating in the standards project, including Ford Motor Co., Chrysler LLC, Toyota Motor Corp., Honda Motor Co. Ltd., Nissan Motor Co. Ltd., Mitsubishi Motors Corp., Daimler AG, BMW AG and Tesla Motors Inc. Utility companies and connector manufacturers also are involved.

France's PSA Peugeot Citroen and Renault SA both say they will put plug-in vehicles on the market in Europe that use the J1772 connectors.

The process began with a connector competition, in which the committee took a look at components already on the market.

“None (of the suppliers) had what we wanted,” Kissel says. “We wanted a small connector with as much power as we could get. And we wanted to make sure it was a design a number of companies would be able to make.”

A concept was settled on in January 2008, and the connector has been in testing since late last year. Kissel expects that process to be completed and the connector to get Underwriters Lab safety certification in the next month.

The connector used for testing was produced by Yazaki Corp.

The new standard, which applies to connections made to both 110- and 220-volt lines, will be adopted for all of North America, not just the U.S., and Kissel says Japan also appears ready to jump on board with the new requirements. It is unclear whether the European Union, which has a different electrical infrastructure, will follow suit or adopt its own standards.

J1772 calls for a 5-pin design with a charging level of up to 80 amps/240 volts and 16 amps/120 volts. It also sets parameters for power delivery and limiting electromagnetic interference, as well as complying with Federal Communication Commission frequency standards.

It does not specify the shape of the handle for the plug.

“We wanted to allow for some design flexibility, but we do provide some boundaries on what that design can be,” Kissel says.

The connector is being certified for 10,000 mating cycles.

“People say, ‘Why can't you just use the type of connector you have with an electric stove?’” Kissel says. “But those aren't designed to be plugged in and out repeatedly.”

The validation testing under way puts the J1772 connectors through much harsher environments than they are likely to see in the real world. “They're being dragged through dust and saltwater,” he says.

The standard sets requirements for the latching system on the vehicle, itself. It requires levels of communication that enable the vehicle to detect when a charge connector is attached in order to prevent it from being driven away while plugged in.