In preparation for the next generation of electric vehicles and advanced battery technologies, General Motors will invest $449 million to upgrade manufacturing processes at its Detroit-Hamtramck Assembly and Brownstown Battery Assembly plants.

The investment is the largest to date at both facilities and includes $384 million at Detroit-Hamtramck for new body shop tooling, equipment, and additional plant upgrades to build the next generation Chevrolet Volt and two future products. This brings GM’s total investment at Detroit-Hamtramck to more than $1 billion over the last five years.

GM’s $65-million investment at its Brownstown Battery Assembly will support the next generation of lithium-ion battery production and future battery systems.

Since 2009, GM has announced more than $5.4 billion in US facility investment for vehicle technologies that benefit customers. This includes more than $2.8 billion invested in Michigan-based facilities alone.

The Detroit-Hamtramck Assembly Plant is the only automotive plant producing GM’s extended-range electric vehicles—including the Volt, Cadillac ELR and Opel Ampera—for markets in 33 countries.

Detroit-Hamtramck also builds the Chevrolet Malibu and Impala sedans and is home to a 264,000-square-foot photovoltaic solar array that can generate up to 516 kW of electricity, or enough to charge 150 electric vehicles per day.

Brownstown Battery Assembly’s 479,000-square-foot, landfill-free facility south of Detroit produces the lithium-ion battery packs for GM’s extended-range electric vehicles. It started mass production in October 2010 and is the first high-volume manufacturing site in the US operated by a major automaker for automotive lithium-ion battery production. The site was made possible with the help of American Recovery and Reinvestment Act funding through the US Department of Energy.