Hyundai and LG Energy Solution are spending an additional $2 billion and hiring an extra 400 workers to make batteries at the automaker's sprawling U.S. electrical vehicle plant that is under construction in Georgia.

Hyundai Motor Group and LG Energy Solution said Thursday they will spend an additional $2 billion and hire an extra 400 workers to make batteries at the automaker’s sprawling U.S. electrical vehicle plant that’s under construction in Georgia.

The announcement by the South Korea-based companies — one a major automaker, the other a leading producer of lithium-ion batteries used to power electric vehicles — expands on a partnership they launched three months ago to produce batteries at the same site west of Savannah, where Hyundai plans to start EV production in 2025.

The news Thursday brings the companies’ total investment in the Georgia plant to more than $7.5 billion and the site’s overall planned workforce to 8,500.