DETROIT (AP) — The U.S. operations of electric car battery maker A123 Systems filed for bankruptcy protection and its automotive assets are being acquired by Johnson Controls for $125 million.

The announcement Tuesday comes one day after A123 warned in a regulatory filing that it likely would miss some debt payments and could be headed for bankruptcy court.

A123, based in Waltham, Mass., got a $249 million U.S. government grant to help it build a battery factory in Michigan.

The bankruptcy filings do not include A123′s subsidiaries outside of the U.S. But those assets also will be sold.