Will the New Mercedes-Benz CLA Skip Liquid Cooling Like the Vision EQXX Did?

Mercedes-Benz could have helped more to clarify that with the info it disclosed about the Concept CLA Class. It does not mention anywhere how the Battery Management System (BMS) keeps the battery pack at ideal temperatures. Air-cooled systems fail to keep the temperature down in fast charging – which slows the process down – and are not very good at heating it in cold weather. If they are too hot, performance issues are the least of the owner's concerns: lifespan may drop as well. In extreme cases, they may even catch fire.

The last electric car with air cooling to be put for sale was the Dacia Spring. GreenNCAP considered it the most efficient vehicle for sale, but a unit caught fire in Romania. The Romanian brand never gave us any explanation for the blaze. The first was the Nissan LEAF, which was involved in the Rapidgate episode. Nissan limited the charging speed of the vehicle when the battery was already hot. As owners discovered the trick, the Japanese company called it a safeguard, proposing to remove it from the cars of owners who gave up on that "protection." That is the perfect excuse to void the warranty, but I have not heard of any such cases. Summing up, air cooling for electric cars may improve efficiency, but there's a cost.

First of all, it is crucial to remember how the Vision EQXX achieved its impressive energy-consumption numbers. Mercedes-Benz tackled the three pillars of automotive efficiency: aerodynamics, mass, and powertrain optimization. In internal combustion engine (ICE) cars, the inherent gluttony of their mills makes efforts in the first two factors the ones that really pay off. The Achille's heel of battery electric vehicles (BEVs) is weight.

The Vision EQXX had a drag coefficient of only 0.17 and a small frontal area, which made it an aerodynamic beast. Its electric motor was also highly efficient, transforming 95% of the energy stored in the batteries into movement. However, its main effort in reducing mass and increasing energy density was achieved by eliminating liquid cooling.

According to Mercedes-Benz, the Vision EQXX can run 10 kilometers per kWh, which is equivalent to 6.2 miles/kWh. The most efficient electric car ever sold was the Lucid Air Dream Edition, which achieved 4.4 miles/kWh (7 km/kWh). Lucid still sells the most efficient battery electric vehicle (BEV): the Air Grand Touring. With a range of 469 miles and a battery pack delivering 112 kWh, it reaches an energy consumption of 4.2 miles/kWh (6.8 Wh/kWh. The production CLA should beat that, but we have yet to understand how it will pull that off.

Mercedes-Benz said that the Concept CLA Class spends 12 kWh/100 km. That is equivalent to 5.2 mi/kWh (8.3 km/kWh). All we have to justify that figure are some clues about what the production version of this vehicle should offer when it arrives in 2025. We do know that it will work at 800V, which allows BEVs to charge at higher speeds. The higher voltage suggests liquid cooling is a must.

Something else reinforces that: Mercedes-Benz should adopt BYD's Blade Batteries on the CLA. CarNewsChina shared a report from the China Battery Enterprise Alliance (CBEA) that states the German carmaker will adopt these LFP cells in its entry-level BEV. That makes sense for several reasons, starting with the lower price for these components.

Blade Batteries have a reputation of being extremely robust. They accept to be fully charged constantly – that's even advisable for LFP cells. BYD also states they have a life cycle of 8 years or 1.2 million kilometers (745,650 miles). The Chinese carmaker also claims they are not prone to fires, but there have been some blazes that it never cared to explain – and it should.

Mercedes-Benz and BYD are no strangers, either. They are partners on Denza, a luxury car company they founded in 2010 that never went that well when the German carmaker ruled the show. The Chinese luxury brand had a single model that did not sell as much as Mercedes-Benz wanted. That changed when the German automaker decided to reduce its stake in the joint venture to 10% and left BYD with the other 90%. The brand is now blooming in sales, with three models in its lineup and some others in the pipeline.

Blade Batteries are placed in BYD cars in two kinds of construction: cell-to-pack (CTP) and cell-to-body (CTB), which increase energy density. Cooling relies on liquids, which suggests Mercedes-Benz may have also adopted it in the Concept CLA Class. That could explain why this vehicle is less efficient than the Vision EQXX, but not why it is so close: it presents 83% of the efficiency of its older brother. If it really has liquid cooling, that's an amazing accomplishment.

Mercedes-Benz said the Concept CLA Class can travel 750 km (466 miles) under the WLTP cycle on a full charge. Should the production version present the same numbers and confirm it will use Blade Batteries, these LFP cells will be only for the entry-level derivative. That means the German carmaker will have at least two different battery pack options. This 750-km range should come from an accumulator with ternary cells, which have a higher energy density. Another hypothesis is that it just gets there through efficiency and a larger battery pack than BYD products currently have. We'll have answers for that until 2025.