Automotive group Stellantis and technology company Factorial have achieved a significant technological breakthrough by integrating Factorial’s advanced FEST (Factorial Electrolyte System Technology) solid electrolyte battery technology into the Dodge Charger Daytona development vehicle. This marks the first integration of solid electrolyte cells into a Stellantis vehicle and the first automotive application of this technology on North American soil.
At the same time, a road test program was launched to confirm the performance, safety and reliability of the new system under real driving conditions. All this builds on the previous tests of FEST cells and represents a key step towards their serial application in the industry.
New architecture
The transition from laboratory testing to installation in a functional vehicle required complex solutions from the engineers of both companies. The solid electrolyte battery cells are incorporated into the existing battery pack housing using a patented mechanical architecture designed by Stellantis. The main aim of this adaptation was to get the most out of the cells’ performance, while the control systems and the design of the package itself were modified to meet the strict automotive safety and durability standards.
During previous tests conducted in 2025, Stellantis and Factorial demonstrated that FEST cells achieve energy densities as high as 375 Wh/kg. The technology enables fast charging, whereby the battery is charged from 15% to 90% capacity in just 18 minutes. Also, the cells showed a high level of reliability in a wide temperature range, from -30°C to 45°C, which is essential for stable operation in all climatic conditions.
The currently launched road test and calibration program will serve engineers to precisely adjust and verify the operation of the battery pack. By driving on public roads, the behavior of the system during charging and different driving modes will be checked, with continuous monitoring of the car’s general safety.