A 2025 Mercedes-Benz EQS fitted with an experimental solid state battery pack has driven 1205km from Stuttgart in Germany to Malmo in Sweden on a single charge, with more than 137km of range remaining.
The result beat the previous record set by the Mercedes Vision EQ XX concept car by 3km. The German brand’s chief technical officer Markus Schäfer said the prototype EQS used for the validation drive would have been capable of covering as much as 1400km if the team hadn’t stopped.
Developed in partnership with US battery-maker Factorial Energy and the Mercedes-AMG F1’s High Performance Powertrain division in the UK, Schäfer would not confirm any details of the new powerpack.
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But he did admit the tech would not arrive until 2030 in production models.
“The solid-state battery is a true game-changer.
“We’re showing it’s possible. We can handle it. It [solid-state batteries] works in a car, it drives perfectly, so we took a big step here but now we have to mature it to series production.”
The engineering chief said that one of the biggest problems of the new tech is the tendency of the cells to swell in size and expand as it gets hotter.
Engineers are working around the issue by using pneumatic actuators that respond to the change in volume as the battery discharges and charges.
Despite using the same casing as the standard 108kWh (usable) battery, Mercedes says the usable energy content of the solid-state power pack increased by 25 per cent even though its weight and physical size remained the same.
Engineers also said that they developed a new “passive airflow cooling” system that helped boost efficiency further.
There’s no mention of safety or charging speeds, but without a liquid electrolyte it’s understood the new tech will be more resistant to thermal runaway, fires and explosions while being capable of charging speeds above 1000kW.
It’s expected that Mercedes will reveal a new concept powered by the battery tech in the near future, previewing an advanced all-electric production vehicle.
It’s been tipped that car will be the first to receive the tech before the end of this decade. That could coincide with the next-generation S-Class limo’s arrival.
