Bob Kruse, who recently led a critical Chevrolet Volt team and devised the automaker’s long-term electric vehicle strategy, has resigned months before the vehicle’s debut, The Detroit News has learned.

Kruse’s resignation, effective end of September, comes at a crucial time for General Motors Co., which is banking on the Volt to change public perceptions of the company and also help meet stringent new fuel rules.

Kruse, 50, executive director of global vehicle engineering for hybrids, electric vehicles and batteries since early 2008, left to start his own consulting company, E V Consulting LLC. He will provide automotive and vehicle electrification expertise for companies looking to seize a piece of more than $1.3 billion in federal grants available to Detroit’s Big Three automakers and the state.

“My departure from General Motors has nothing to do with my view of the future success for the Volt,” Kruse said on Tuesday. “I’ve left on very good terms. I have a lot of respect for the leadership of General Motors.”

But, he added: “I’m not going to lie. Are they happy about my departure? Probably not.”

GM said the extended range electric Volt remains on target for production in November 2010 and stressed that Volt battery testing was under way when Kruse was promoted. The team is largely responsible for designing and testing the Volt’s lithium-ion battery. Kruse’s team also focused on integrating the battery into the vehicle, and he developed GM’s battery and electric vehicle strategy beyond the Volt.

The company will soon have 80 pre-production Volt vehicles on the roads.

“There’s no good time to lose good people,” GM spokesman Rob Peterson said. “But that said, the Volt team goes way beyond one person.”

Kruse’s move is understandable given the amount of federal money available, cuts imposed on white-collar workers and retirees by GM and government restrictions on executive pay, said analyst Joe Phillippi of Auto Trends Consulting Inc. in Short Hills, N.J. More