Making the Vision EQXX the standard for EV performance means avoiding a downward spiral.
That’s one of the main reasons Mercedes-Benz stuck with the idea of an air-cooled battery pack in the Vision EQXX concept. Listening to project manager Malte Sievers, that was one of the key decision points on the project that helped allow it to go far beyond its original goal: 1,000 kilometers (621 miles) on a single charge, at real-world speeds. .
“The introduction of liquid cooling into that battery will start in a spiral — and you can see this with a lot of larger systems,” explains Sievers. Green car report last week, at Mercedes’ Immendingen proving ground, before I was allowed to take the driver’s seat of this futuristic car (and the only such car on Earth).
Bottom line: Liquid cooling adds weight and increases the height of the battery pack. That will increase the vehicle’s height to maintain interior space — which will increase frontal space and affect aerodynamics. And that combined will increase the required power and therefore the size of the battery required.
Mercedes-Benz Vision EQXX 1008 km
Mercedes-Benz Vision EQXX 1008 km
Mercedes-Benz Vision EQXX 1008 km
As we reported, the futuristic Vision EQXX is the most efficient car Mercedes-Benz has ever built. In April, EQXX did a real-world run, which included a 746-mile trip from Stuttgart, Germany, to Silverstone, England, with just one charge and have backup power for several winning rounds.
EQXX is not a manufactured vehicle in any way. It’s proof that the automaker’s electric vehicles can be made more efficiently — far more efficiently — in the future.
As Sievers outlined, the EQXX represents an all-hands approach that ensures every part of the vehicle — including but not limited to the propulsion system — follows the path of neatness and efficiency. possible.
“To make this a reality and make it the most efficient Mercedes we’ve ever built, you need to look at each area of the car that affects efficiency — and that’s basically all. everything,” he said.
Concept Mercedes-Benz Vision EQXX
From 20-inch forged magnesium wheels and slim Bridgestone Turanza Eco tires, specially developed for the EQXX, to fiberglass-reinforced plastic for the doors and mega-cast aluminum at the rear, with integrated throttle tower , EQXX is fighting for a different future, more effective in every way.
And when I turned to ask more about the cooling, Sievers quipped, with a smirk: “We really don’t.”
He is speaking right. The EQXX battery pack features a number of carefully selected cells, arranged in a way that doesn’t require anything more than outside air to enter. Sometimes.
Sievers says that at the demonstration facility, in the summer heat, the EQXX’s pack was not significantly higher than the ambient temperature — 86 degrees Fahrenheit while we were talking, with a peak of 99 degrees in the morning. that afternoon. He reports from remote sensing that the pack is currently at 90 degrees.
Mercedes-Benz Vision EQXX
As for those cells, Sievers commented that due to improvements in internal resistance, the cells simply don’t heat up as much during charging as they did in previous generations.
“It shows that there is a lot to be achieved, even in the realm of conventional chemistry today,” he said, perhaps a hint of what the automaker is looking at for the future. those electric cars of the future. “And it’s all not just solid state; There are a lot of new things popping up all around. “
Even so, the EQXX doesn’t completely avoid cooling. There is coolant for the electric drive and inverter, plus an oil-water exchanger that helps keep the motor bearings cool. Shutters open at the front of the car open only when needed, allowing a thin stream of air to pass through the battery and those systems, pulling heat out.
Mercedes-Benz Vision EQXX 1008 km
Mercedes-AMG’s high-performance powertrain, which works with Formula E and Formula 1, has designed a frequency converter for the car, which runs on a “900-volt plus system”. The inverter is heavily integrated with Formula E formulas and is an important part of the overall efficiency of the electric drive system to 95% from cell to wheel. The inverter looks “different from anything we’ve done so far,” says Sievers.
“We’re basically chasing every watt here,” said Julien Pillas, a principal engineer working specifically on electric powertrains.
Much of the powertrain development for the EQXX, which began in 2020, was done on a car nicknamed Emma — for upcoming MMA platform. Launching around mid-decade with models roughly the size of the Tesla Model 3 and Model Y, that platform will reap some of the benefits of the EQXX project. Emma, the burgeoning mule crossover, weighs almost 5,300 pounds with an EQXX’s approximately 100 kWh air-cooled package mounted underneath. That’s just a few hundred pounds more than the weight of the production EQB with its 70.5 kWh liquid-cooled package.
Thanks again to the air-cooling feature for the EQXX pack’s 1,089-pound weight — and by extension, for its under 3,900 lb total weight.
Mercedes EQB with EQXX powertrain and battery –
I had to shoot Emma first, on a closed course, to get a feel for the look and feel of the accelerator and brake pedals, which are exactly the same as the EQXX (albeit with more mass). Part of that has to do with getting used to regenerative braking, which is much more aggressive than Mercedes’ current electric cars – keeping modes from D- (moderate reverse) to D+ (glide) but added “D–” mode that allows driving with one pedal without holding the brake. Maintaining peak performance in the EQXX also involves keeping the accelerator lightly pressed and staying within the 25 kW power range.
In the data collection proof base with the engineers, they are keeping the telemetry for us. So I was able to effectively test — and more — for my drives. On a loop of approximately 16 km (10 miles) – covering a variety of terrain and speeds up to 100 km/h (62 mph) and averaging about 50 km/h (30 mph)—I reached averaged 12.1 kwh/100 km (5.1 mph) in Emma, almost double the performance I’d seen on the national detour in the EQB earlier that day.
That proved the value of the powertrain. Now I’ve gone out into reality — EQXX with nice body and drag coefficient 0.17.
I slid into the mushroom vegan leather replacement seats and pulled on the Biosteel fiber door straps, adjusted the seat and found it actually quite comfortable for my 6-foot-long frame.
Mercedes-Benz Vision EQXX
The EQXX certainly feels more comfortable and I found myself driving faster than the SUV, which requires the constant attention of the speedometer to stay within the speed zone of the proof zone. While I heard the whine of the powertrain and a bit of road noise, there was almost no wind noise – the bonus of the air-conditioned car.
After a bit of fun after effective revs, I got a chance to tap into the full 180 kw (241 hp) and verify that the contact steering and very low center of gravity make this car quite enjoyable. taste when driving fast.
Efficiency for EQXX . drives
And then, a final tally. In the EQXX, I averaged 8.39 kwh/100 km — about 7.4 mph, or about 45% better than what I saw in Emma. Or almost twice the distance on the same kWh that I can cover in most of the relatively efficient electric vehicles on sale today.
An interesting part of the EQXX efficiency puzzle is solar energy. In the EQXX, it only runs into a 12 volt system, with no power path to the pull pin. The system’s peak power is around 600 watts, with the system capable of achieving a range of about 16 miles during the day.
Mercedes-Benz Vision EQXX
Sievers admits that’s not necessarily a decision they would make in a production model — like skipping the built-in charger, for example. But for the EQXX and the purposes of running its range, it makes the best sense and frees up the pull pin for high voltage use—running a DC-DC converter occasionally as needed. In the EQXX, the heat pump is run off the high-voltage system, but the rest of the climate control, steering, controls, infotainment system and more all run at 12 volts.
Likewise, the EQXX is not built for fast charging. Though its air-cooled pack can charge at 140 kW without any heat build-up – enough to achieve a range of 186 miles in 15 minutes.
“We’re not trying to prove that fast charging is wrong,” says Sievers. “Although for the sake of efficiency, we quickly discovered that this actually helps with charging quite a bit — this is the interesting technical aspect of this, that we’re actually figuring out. new things we haven’t seen coming.”
While project participants hesitate to offer any further hints as to what exactly could make it to MMA electric vehicle production, we’ll take that as one of the suggestions.
Mercedes-Benz Vision EQXX
In some ways, EQXX is this decade VW XL1, like a super-effective poster car. Although VW has built the ultralight XL1 diesel-hybrid engine in very small quantities, like the EQXX, it is intended as a technology canvas.
That said, after learning why the EQXX exists — and driving it — I can say that while the EQXX won’t be produced, it makes a lot more sense in helping guide a generation of EVs out of that downward spiral.
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Mercedes-Benz provided transportation and accommodation so we could bring you this test drive review.
