It’s almost as slippery as a penguin, with a shape inspired by a drop of water, but it’s the 1,000km (620 miles) range of the latest Mercedes-Benz concept car, the Vision EQXX, which is capturing the headlines.

This sort of battery range between charges has been seen as something of a holy grail for electric vehicle (EV) developers, as it would put the vehicle’s utility in line with that of a good turbodiesel passenger car, without the exhaust emissions and with far less CO2 produced per mile. Even Tesla has yet to get near this kind of range, although in 2020 Elon Musk boasted about having the technology under development.

So, Mercedes has taken the initiative in what was to have been its centrepiece at the Consumer Electronics Show in Las Vegas (the company pulled out of full participation before Christmas). True, these range claims have not been tested in any sort of WLTP test, and instead are based on what are termed “internal digital simulations in real-life traffic conditions,” but it’s a bit more than just the usual Vegas vapourware we’ve become used to over the years.

“The technology programme behind the Vision EQXX will define and enable future Mercedes-Benz models and features,” says Markus Schäfer, the company’s director and chief technology officer.

He goes further, promising that the concept is also a precursor of a new medium-sized battery Mercedes model due in 2024. Quite whether this near five-metre long, four-seat saloon powered with experimental battery technology would make it largely unchanged to the showrooms remains to be seen. Nor are there any indications on what a car like this would cost.

So, what has Mercedes learned in the unusually short 18-month development period, during which suppliers, outside companies, start-ups and even the Formula One specialists at Mercedes-AMG High Performance Powertrains (HPP) in Brixworth, Northampton were pressed into service to speedily hone the efficiency of the EQXX?

The battery

This 900-volt lithium-ion battery drivetrain delivers an output of 201bhp from almost 100kWh of battery power. A similarly powerful battery lives in the EQS large electric saloon with a 453-mile range, which was launched last year, but this one is half the size and weighs 30 per cent less.

The pack weighs just 495kg and uses the ‘cell-to-pack’ technology pioneered by Catl, the Chinese battery supplier with which Mercedes signed a cooperative deal in August 2020. Cell-to-pack dispenses with the cell modules used in current cell designs and integrates the cells directly into the casing, which cuts down on weight and bulk.