Stellantis and Factorial have begun public road testing of solid-state battery technology using a Dodge Charger Daytona development vehicle, marking what the companies described as the first automotive integration of the technology in North America.
The programme represents the next stage in a multi-year collaboration between Stellantis and Factorial, which first announced plans in 2024 to deploy a demonstration fleet equipped with the US company’s FEST (Factorial Electrolyte System Technology) cells.
According to the companies, the road-testing programme is intended to validate battery performance, safety and reliability under real-world conditions. The cells have been integrated into a modified battery pack featuring a patented mechanical architecture developed by Stellantis engineers.
“Battery development is a balancing act. It’s not enough to optimise 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.”
Factorial’s automotive-scale FEST cells were validated in 2025. The 77Ah cells offer an energy density of 375Wh/kg and can charge from 15% to more than 90% state of charge in 18 minutes at room temperature. They have also demonstrated operation across temperatures from -30°C to 45°C and discharge rates of up to 4C.
Stellantis said adapting the cells for use in a vehicle required extensive changes to battery-pack architecture and control systems to meet automotive safety and performance requirements.
The Charger Daytona development vehicle is the first phase of a broader programme aimed at bringing solid-state batteries closer to commercial production. Factorial also counts Mercedes-Benz, Hyundai and Kia among its strategic partners.
Siyu Huang, chief executive and co-founder of Factorial, said: “Bringing solid-state batteries from the lab to the road is an achievement few thought possible just a few years ago. This milestone with Stellantis demonstrates that next-generation battery technology is no longer just a promise, it is becoming a reality.”
Effect on Factorial’s share price
The announcement did not produce a positive share-price reaction, however.
Factorial only recently completed its Nasdaq listing under the ticker FAC, and its shares had risen sharply following the debut, gaining roughly 40% over the week.
However, despite the significance of the Stellantis milestone, investors took profits and the stock fell sharply on the day of the announcement. According to Benzinga, Factorial shares were down almost 20%, to around $17.60, on 11 June.
The decline appears to have reflected volatility following the company’s recent market debut rather than any negative interpretation of the road-testing programme itself. In other words, the announcement was viewed as technically positive, but it coincided with a pullback after an exceptionally strong post-listing rally.
Photo: this Dodge Charger Daytona EV is powered by Factorial Energy’s FEST technology
Credit: Stellantis
