GM's top battery executive for the Volt to join California startup

General Motors's top executive in charge of developing batteries for the Chevrolet Volt plug-in hybrid is leaving to take a position with an unnamed startup battery company in California.

Denise Gray, 46, global director of rechargeable energy storage systems, will step down March 5 after more than three years in the post.

This was “an opportunity that I could just not resist,” Gray said in a phone interview. “The good thing is I will be in the energy, advanced-battery area that I really truly believe has a promising future.”

Gray added that she is “a strong supporter of the Volt and what GM is doing” but that she will be cheering from “a different seat.”

Ronn Jamieson, director of global battery systems engineering, will temporarily assume reporting responsibilities for Gray's staff. Bill Wallace, manager of the Volt Battery System Engineering Group, will take on technical and program management responsibilities.

The Volt, GM's flagship for a fuel-saving future, is designed to travel 40 miles on its battery before the gasoline engine starts. The vehicle will roll out slowly, starting in California. Production is targeted at 8,000 to 10,000 in the first full year. GM plans to ramp up to 50,000 to 60,000 annually.

Gray said “there is never an ideal time to leave.” She noted that GM built the Volt's first production battery pack in January.

“The heavy lifting when it comes to the battery design is complete,” she said. All that remains “is fine tuning to make sure our manufacturing processes and all of our testing is in place.”

She will be the third key executive to leave the Volt team in the last six months.

In September, Bob Kruse, executive director of vehicle engineering for hybrids, electric vehicles and batteries, left to start a consulting firm. A month later, Frank Weber, the German-born engineer in charge of the Volt program, announced his return to Germany. He was named Opel's vice president of global product planning in late November.

Gray worked for GM as a high school senior in 1980. She has directed a variety of engine and transmission activities in more than 25 years at the automaker.

By Rick Kranz- Automotive News