Why the Mercedes CLA electric 800 km of autonomy already disappoints

It is a small line in the French brochure of the new Mercedes CLA electric. A technical clarification that looks like nothing, but that changes a lot to use: the new Mercedes electric car can only recharge on fast 800 volts. It’s written black on white: ” Charge system for DC MOTHERS (DC) 800V only ».

Concretely, this means that this Mercedes is today incompatible with a vast majority of rapid terminals deployed in Europe, including those of Tesla, whose supercombtors still operate in 400 volts as confirmed by the specialized German blog MB Passion.

To go further
Why the 800 volts electric cars will be line up the current models

Note that it is always possible to recharge on slow terminals by alternating current (as at home), at a maximum power of 11 kW. We are talking here only about fast terminals, like those found on the highway for example.

An ambitious electricity CLA … but capricious

Announced as a technological showcase of Mercedes on the compact sedans segment, this new electric CLA is not lacking in arguments. A brand new MMA platform, a content rate, a very low consumption, announced at 12 kWh/100 km (it’s better than on the Tesla Model 3, however excellent on this game) and an ultra-fast recharge possible up to 320 kW, thanks to 800 volts architecture. Or a 10 to 80 % shipped in just 22 minutes, as on an Ionity or Fastned terminal.

For comparison, a Tesla performs this exercise in 20 to 35 minutes depending on the model, in 400 volts.

But this flash recharge promise has a price: the car simply does not know how to adapt to lower tensions. In the absence of a DC/DC converter on board, it is impossible to recharge on the many stations which still cap at 400 volts, and therefore on a beautiful part of the current network.

Competitors are however capable of this. Like the Porsche, which integrate a converter (booster), or like the Kia and Hyundai, who use the engine for the conversion of 400 to 800 volts.

Mercedes is already working on a solution

Mercedes recognizes the limit, and plans to offer a 400 -volt compatibility option in the future. But in how long? At what price? Will it be possible to add it in the second rising?

Concretely, this means that the Mercedes CLA will not be able to recharge on the Tesla Superchargers, currently limited to 400 volts, and many terminals of the same kind. They are often recognized by their maximum limited power around 150 kW. But sometimes it is not clear, because a terminal can announce a higher power (for example 300 kW), but by dividing it into 2 x 150 kW with two charging points.

In short, it may be a headache for the first customers of the electric CLA. Fortunately, Mercedes reassures and indicates that the route planner integrated into GPS does not redirect the driver only to 800 volts.

The good news is that Fastned has already been able to test the Mercedes CLA on a 400 kW terminal. The maximum power reaches 353 kW as we can see on the image, with a rather good charging curve.

Note that the Tesla Superchargers will switch to 800 volts in a few months. But only the V4 superchargers, provided that the American manufacturer changes power cupboards. The former supercombling will always be limited to 400 volts.

As Bloomberg recalled in February 2024, in Germany, out of a total of 16,300 charging stations over 100 kW of power, there were 8,000 400 volt terminals against 7,300 800 volts terminals.