Stellantis and Factorial Inc. have reached a significant milestone: the integration of Factorial’s advanced FEST® (Factorial Electrolyte System Technology) solid-state battery technology into a Dodge Charger Daytona development vehicle and the launch of a road-testing program to verify performance, safety and reliability. Building on previous validation of automotive-scale FEST® cells, this achievement marks the first integration of solid-state cells into a Stellantis vehicle and a breakthrough step towards automotive-grade application.
“Battery development is a balancing act. It’s not enough to optimize a single metric. We need a system that delivers real benefits in a real vehicle,” said Ned Curic, Stellantis Chief Engineering and Technology Officer. “This milestone shows we are bringing solid-state batteries closer to our customers with the potential for longer range, faster charging and lower costs. Just as important, FEST®’s strong compatibility with lithium-ion manufacturing processes gives us a critical path to scale this technology.”
In 2025, Stellantis and Factorial demonstrated FEST® cells with an impressive energy density of 375 Wh/kg, ultra-fast charging from 15% to 90% in just 18 minutes and robust reliability from -30 °C to 45 °C.
Transitioning from these cell testing results to a development vehicle demanded advanced engineering solutions from Stellantis and Factorial engineers. FEST® solid-state battery cells were integrated into the existing battery pack using an innovative, patented new mechanical architecture, designed by Stellantis, to bring out the best of solid-state cell performance. Engineers also adapted the control systems and pack design to optimize cell performance while meeting rigorous automotive requirements for safety and durability. These technical designs and adaptations are essential for ensuring cell performance in all conditions.
With this integration milestone complete, Stellantis and Factorial have started a road testing and calibration program. The testing program will help tune and further verify pack performance and reliability under charging and driving conditions, in addition to vehicle safety.
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12 June 2026
