Stellantis and battery developer Factorial have officially moved solid-state battery technology onto the street, announcing that a Dodge Charger Daytona development vehicle is now undergoing testing with advanced solid-state battery cells.The milestone marks the first integration of Factorial’s FEST (Factorial Electrolyte System Technology) solid-state batteries into a Stellantis vehicle and the first automotive application of the technology in North America.The companies said the Charger-based prototype is being tested in a calibration program designed to evaluate battery performance, safety, durability and reliability under real-world driving and charging conditions.Solid-state batteries are widely viewed as one of the most promising next-generation EV technologies because they could deliver greater energy density, faster charging, safer everyday use, and lower costs than the lithium-ion batteries currently found in most electric vehicls. In 2025, Stellantis and Factorial demonstrated FEST cells capable of 375 Wh/kg energy density, charging from 15 percent to 90 percent in just 18 minutes, while operating in temperatures ranging from -22 degrees F to 113 degrees F.battery module designed for electric vehiclesStellantis said integrating the cells into a production-based vehicle required significant engineering work. The automaker had to develop a patented battery-pack architecture designed specifically to accommodate the solid-state cells while maximizing their performance. Engineers also modified battery controls and pack systems to meet automotive safety and durability standards.“Battery development is a balancing act,” said Stellantis Chief Engineering and Technology Officer Ned Curic. “This milestone shows we are bringing solid-state batteries closer to our customers with the potential for longer range, faster charging and lower costs.”Autoweek SOC EV Newsletter sign upThe Charger test vehicle is the first step in a previously announced multi-stage development program between Stellantis and Massachusetts-based Factorial, which counts Stellantis, Mercedes-Benz, Hyundai ,and Kia among its strategic investors and partners.The companies said the road-testing phase will help validate the technology as they continue working toward future production applications.