Mercedes-Benz CLA EV Can’t Charge At 400-Volt Chargers

Mercedes-Benz launched the all-electric CLA in March, promising the most advanced EV platform to date. However, Mercedes-Benz screwed up big time, as the 800-volt EV is incapable of charging at 400-volt DC fast chargers. That’s because the carmaker skimped on a DC-DC converter, although it promised to offer one as an option in the future.
 

Mercedes-Benz wasn’t very successful with its EQ all-electric models, mostly because the customers did not appreciate the egg-shaped design. The German carmaker changed its strategy by ditching the EQ brand and launching EVs as part of its regular lineups. The first model to encompass the new ethos was the CLA, offered with all-electric and hybrid powertrains. The former is called CLA with EQ Technology, a complicated designation unlikely to become popular with customers.
 
The all-electric CLA promised to be Mercedes-Benz’s most advanced electric vehicle, sporting a cutting-edge 800-volt architecture. It allows charging at up to 320 kW, beating the 250-kW peak power that most Tesla EVs offer. The CLA is also one of the most efficient EVs on the market. In short, Mercedes-Benz finally has a winner if we overlook that sedans are no longer the public’s favorites. However, Mercedes-Benz failed monumentally in a key area, likely sabotaging CLA’s career.
 
All EVs sold nowadays can be charged on both 800-volt and 400-volt DC fast chargers and battery management systems or the chargers themselves make sure the battery is fed with the right voltage. Not the Mercedes-Benz CLA, though, which proved incapable of using 400-volt chargers. To be fair, the carmaker warns about this shortcoming in the owner’s manual and on its website, but it hasn’t been very straightforward about it in the press or promo materials.
 
The European-spec Mercedes-Benz CLA lacks a DC-DC converter or other method to boost the 400-volt voltage most DC fast chargers output. So far, it’s unclear whether the car sold in the US will include a booster. Most DC fast-charging stations in the US, including Tesla Superchargers, are 400-volt stations. However, even in Europe, there are many 400-volt chargers that Mercedes-Benz CLA owners will not be able to use.
 
Carmakers use several methods to accommodate 400-volt and 800-volt chargers. For 400-volt EVs, including all Tesla models except the Cybertruck, no conversion is needed, as the DC fast-chargers take care of this. Some 800-volt EVs, including the Cybertruck, split the battery pack into two 400-volt banks and connect them in series or parallel to match the input voltage.
 
Others use a DC-DC converter, which is a less efficient method because charging is limited to the power capacity of the converter. This is why most Hyundai and Kia EVs don’t charge very fast at 400-volt stations like Tesla Superchargers. The same limitations affect the Porsche Taycan, although Porsche offers higher-power DC-DC converters at least as an option.
 
Mercedes-Benz doesn’t offer any of these voltage conversion methods for the CLA sold in Europe, at least for the time being. However, it plans to provide one in the future as an option. It’s unclear when it will be available and how much it will cost. It’s also unlikely that the converter will be retrofittable to cars already on the road. Hopefully, Mercedes will not dare sell the CLA in the US without a DC-DC converter.