Mercedes-Benz Begins Solid-State Battery Road Tests

Mercedes-Benz engineers from the road and racetrack have teamed up with Factorial Energy to develop an all-new solid-state battery test program, which has brought the first car powered by a lithium-metal solid-state battery to the road. Road tests with the new solid-state battery in a '1,000 km' EQS test car started in February 2025.

Mercedes-Benz joined forces with Factorial in 2021 to develop a new generation of battery technology.

The all-electric car from Mercedes‑Benz was slightly modified to fit the solid-state battery and was equipped with all accessories to operate it.

The first laboratory vehicle tests were already conducted in Stuttgart at the end of 2024 to prepare for the road tests.

The solid-state battery in the EQS-based vehicle allows for up to 25 % more driving range compared to the same battery weight and size of a corresponding standard EQS battery.

Mercedes AMG High Performance Powertrains (HPP), a 100 % subsidiary of Mercedes-Benz Group specialising in industry-leading Formula 1 technologies, and the Mercedes‑Benz Center of Competence for Battery Systems designed and developed the battery system. 

Markus Schäfer, Member of the Board of Management of Mercedes‑Benz Group AG. Chief Technology Officer, Development & Procurement, says: “Developing an automotive-scale solid-state battery underlines our commitment to innovation and sustainability. We’re therefore excited to announce that we’ve started road testing with a prototype vehicle equipped with this advanced technology. We will gain crucial insights into possible series integration of this cutting-edge battery technology.” 

Siyu Huang, CEO and Co-Founder of Factorial Energy, adds: “Being the first to successfully integrate lithium metal solid-state batteries into a production vehicle platform marks a historic achievement in electric mobility. This breakthrough demonstrates that solid-state battery technology has moved beyond the laboratory and into real-world application, setting a new benchmark for the entire automotive industry. Our collaboration with Mercedes-Benz proves that the future of electric vehicles is not just a vision, but a reality we're delivering today.” 

Mercedes-Benz will further test the solid-state battery and its overall performance in an electric vehicle with extensive laboratory and road tests.