Company President and CEO Fritz Henderson has called a news conference for Thursday at the plant site in Brownstown Township, 20 miles southwest of Detroit.
GM says in a statement the factory "will produce the lithium ion battery packs for GM's future extended-range electrical vehicles, including the Chevrolet Volt."
South Korea's LG Chem Ltd. is making the batteries. Two people briefed on the project said last month GM will invest $43 million and employ about 100 people at the plant. They requested anonymity because GM hadn't made an official announcement.