Stellantis and Factorial Bring Solid-State Batteries to the Road with Dodge Charger Daytona Development Vehicle
Stellantis and Factorial Inc. have reached a major milestone in the evolution of electric vehicle technology: the integration of advanced solid-state battery cells into a Stellantis development vehicle and the commencement of real-world road testing. The announcement, made on June 11, 2026, marks the first automotive integration of solid-state battery technology in North America.
The development vehicle, based on the Dodge Charger Daytona platform, incorporates Factorial's proprietary FEST® (Factorial Electrolyte System Technology) solid-state battery cells. Road testing is now underway to validate performance, safety, and reliability under real-world driving conditions, bringing this next-generation battery technology one step closer to production-ready application.
Breakthrough Performance Metrics
In 2025, Stellantis and Factorial demonstrated that FEST® cells could achieve an impressive energy density of 375 Wh/kg, significantly higher than conventional lithium-ion batteries. The cells also demonstrated ultra-fast charging capability, going from 15% to 90% state of charge in just 18 minutes, while maintaining robust reliability across a wide temperature range from -30°C to 45°C.
Transitioning from lab-proven cell testing to an actual development vehicle required advanced engineering solutions from both teams. The FEST® solid-state battery cells were integrated into the existing battery pack using an innovative, patented new mechanical architecture designed by Stellantis engineers specifically to optimize solid-state cell performance. Engineers also adapted the vehicle's control systems and pack design to meet rigorous automotive requirements for safety and durability.
Industry-Leading Collaboration
“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 importantly, FEST®’s strong compatibility with lithium-ion manufacturing processes gives us a critical path to scale this technology.”
The battery pack's patented mechanical architecture is designed to accommodate the unique requirements of solid-state cells while maintaining compatibility with existing manufacturing processes. This compatibility is critical for scaling the technology to mass production levels.
“We are deeply honored to work alongside Stellantis, one of the world's great mass-market automakers, on this STLA Large-based development car,” said Siyu Huang, CEO of Factorial. “What we have built together, from cell chemistry to pack architecture to enable real-world road testing, is exactly the kind of deep, full-stack collaboration that solid-state has always required. This milestone doesn’t just validate FEST®; it sets a new bar for what automotive-grade solid-state batteries can deliver.”
What This Means for the Future of EVs
Solid-state battery technology has long been viewed as the “holy grail” of electric vehicle power storage, offering the potential for significantly greater energy density, faster charging times, and improved safety compared to conventional lithium-ion batteries that use liquid electrolytes. By replacing the liquid electrolyte with a solid material, solid-state batteries can store more energy in the same physical space while reducing the risk of thermal runaway.
For Stellantis, which owns brands including Dodge, Jeep, Ram, Peugeot, and Fiat, the successful integration of solid-state technology into a production-ready vehicle architecture represents a key step toward its electrification strategy. The Dodge Charger Daytona, already positioned as a high-performance electric muscle car, provides an ideal test platform for showcasing the performance potential of solid-state batteries.
This milestone marks continued progress on Stellantis and Factorial's previously announced multi-stage development vehicle program, as well as an important step in Factorial's ongoing development, calibration, and industrialization of solid-state batteries for automotive use. Factorial is backed by a consortium of major automakers including Mercedes-Benz, Stellantis, Hyundai, and Kia, along with In-Q-Tel, the not-for-profit strategic investor for U.S. national security agencies and America's allies.
The road-testing program will continue to validate performance under charging and driving conditions, bringing the automotive industry closer than ever to a practical, mass-produced solid-state battery electric vehicle.
Image Source: Stellantis Media
