Ultium LLC has announced publicly that it has already started production of batteries for the Hummer EV SUT and SUV. https://www.freep.com/story/money/cars/general-motors/2022/08/31/gm-batteries-ohio-plant-hummer-ev/65466256007/#l7i0w73ead13z7xee0u
https://www.ultiumcell.com/newsroom/News/2022/08/31/Ultium-Cells-Welcomes-Ohio-Governor-Mike-DeWine-to-Tour-Warren-Facility