The end of diesel? Mercedes EQS covers a record-breaking 749 miles on a single charge

Mercedes has broken the EV endurance record for a solid state-battery, after an EQS saloon travelled 749 miles from Mercedes’ hometown – Stuttgart in Germany – to Malmö, Sweden, on a single charge.

The usual distance between the two cities is around 630 miles. But to showcase what a solid-state unit can do, Mercedes engineers plotted an alternative route featuring different topography and and traffic conditions, while avoiding ferry crossings.

Despite the additional 120 or so miles, the EQS finished its trip with 85 miles of range left in reserve.

The solid-state battery used in the record-breaking EQS is said to be “comparable” in size and weight to the EQS’ usual 118kWh lithium-ion unit, which yields up 481 miles of range.

The solid-state battery uses lithium-metal cells produced by US firm Factorial Energy and is co-designed with the Mercedes AMG Petronas Formula 1 Team.

Thanks to a clever floating cell case featuring pneumatic actuators responsible for managing the expansion and contraction of its cells, the solid-state is more stable and durable than a lithium-ion unit. It is also air-cooled, meaning it’s lighter than a lithium-ion battery, and doesn’t experience the power drain of a liquid-cooled system.

Given Mercedes expected the solid-state battery to offer 25% more energy capacity than its regular unit, the big battery EQS was initially expected to manage a range of 620 miles.

Mercedes chief technology, Markus Schäfer, described the tech as a “gamechanger” and that it plans to “bring innovations like this into series production by the end of the decade and offer our customers a new level of range and comfort.”

Solid state batteries are seen as the next big leap in EV powertrain technology. Theoretically, they offer far greater energy density, faster charging and better durability. Their development for mass production has taken longer than expected but there are signs that it is getting closer. Like Mercedes – which is currently in the midst of the biggest launch programme in its 99-year history – the Volkswagen Group announced a similar launch time for its solid state batteries at this year’s Munich motor show.

Rimac Technology also used the event to showcase its solid state battery and in-wheel tech, and Nissan, MG and Toyota are all also poised to launch solid state systems by 2030.