Shares of Amprius Technologies rose after the company got a grant of up to $75 million from the Defense Department to retrofit an existing production line from electric vehicle batteries to high-energy density batteries for drones.

The stock gained 8.7% to $10.60 in premarket trading Monday. At Friday's market close, shares were up 24% year to date.

Amprius said it plans to use the funds to reconfigure a battery production line operated by a major South Korean manufacturer.

The company expects the conversion project to cost about $100 million, including in-kind investments from Amprius and its South Korean partner, and to be complete in early 2028. It expects the line to have the capacity to produce 12 million Amprius cells annually once the transition is complete.

"Our technology, combined with the U.S. manufacturing prowess of our South Korean manufacturing partner, positions us to accelerate adoption of standardized, high-performance pouch cells in a fast-growing market," Amprius Chief Executive Tom Stepien said.