Aircraft battery developer Amprius has secured an order for $15 million worth of SiCore lithium-ion battery cells from an unnamed drone manufacturer. It expects to begin deliveries to the customer in the second half of 2025.

While Amprius did not disclose the customer or reveal any details about the drone that will use its SiCore cells, the California-based battery producer said the purchase order followed field trials with a “fixed-wing UAS platform.” Judging by the aircraft manufacturer’s battery selection, it could be a relatively large drone with high power demands.

The next-generation SiCore battery cells, which Amprius introduced in 2024, are designed for aircraft and other electric vehicles with high-performance specifications. With a power density of 3 kW/kg and an energy density of 370 Wh/kg, the SiCore cells provide rapid energy delivery without compromising on range and endurance, according to Amprius.

“This $15 million purchase order underscores the growing demand for Amprius’ next-generation battery technology and endorses the superiority of our battery performance in the UAS sector,” said Amprius CEO Kang Sun. “Our SiCore cells set a new standard for energy density and reliability in demanding environments, positioning Amprius to lead the rapidly expanding electric aviation sector.”

According to Amprius, the lightweight SiCore cells are ideal for eVTOL air taxis, which draw more power during takeoff and climb than conventional airplanes. Amprius has already secured orders from three electric aircraft developers for the SiCore cells, and those are already being mass-produced by contract manufacturing partners primarily for the EV industry. 

Meanwhile, in addition to the SiCore cells, Amprius has a separate line of high-performance battery cells under the name SiMaxx, which the company is producing at its laboratory in Fremont, California. The SiMaxx cells offer higher energy densities of up to 500 Wh/kg and only half as much power density as the SiCore cells—but with more than double the cycle life, meaning batteries don’t need to be replaced as often. 

Because the SiMaxx cells involve costly and highly specialized manufacturing processes, Amprius is producing them in-house in a limited capacity rather than outsourcing the work to its partners. For now, Amprius is focused on scaling the production of SiCore batteries, which are more profitable and in higher demand. Revenues from the SiCore line will support the expansion of the SiMaxx production line in Fremont as well as a new factory Amprius is building in Brighton, Colorado.