Many car brands are busy electrifying their range. That sometimes misleads consumers, because this does not mean that the cars become fully electric.

In some cases, electrification is about the introduction of a plug-in hybrid drive line, but often it involves nothing more than the addition of a mild hybrid system with a 48-volt network. What is that exactly?

The mild hybrid system means a new addition to an already complicated list of abbreviations. Mild hybrids are known as MHEVs, while the regular hybrid is called HEV. The plug hybrid is called PHEV and the fully electric car BEV.

Abbreviations, meanings and examples

  • MHEV (mild hybrid electric vehicle): Ford EcoBoost Hybrid
  • HEV (hybrid electric vehicle): Toyota Corolla
  • PHEV (plug-in hybrid electric vehicle): Mitsubishi Outlander
  • BEV (battery electric vehicle): Tesla Model 3

Audi, BMW, Ford, Hyundai, Kia, Mercedes-Benz and Volvo are just a few brands that have introduced mild-hybrid technology to their models in recent months.

The new Volkswagen Golf is also equipped with the system, which uses a 48-volt lithium-ion battery that is connected to a belt-start generator. Among other things, this part takes over the task of the starter motor. In addition, the mild hybrid system provides support during acceleration.

Volkswagen initially supplies the technology in combination with the 115 hp three-cylinder petrol engine and the 1.5-liter four-cylinder petrol power source (150 hp). The engines are linked to an automatic. Ultimately, the mild hybrid system must become available for the entire model range. The brand claims a fuel saving of 0.4 liters per 100 kilometers depending on driving behavior.

The new Golf was caught during a photo shoot some time ago. (Photo: AutoWeek)

"Borders of the onboard network have been reached"

However, many systems still operate at 12 volts. That is why most manufacturers who use the technology work with a double system, whereby 48 volts are converted to 12 volts via a direct current inverter and vice versa. For example, electronics that require a low voltage will not break from the 48 volts generated by the new types of starter generators.

"The limits of the 12-volt battery have been reached pretty much. Not from the battery itself, but rather from the on-board network. That peaks at around 250 amps, it can't handle more. If you want more, you need thicker cables Considering the amount of cables already installed in a vehicle, that means a lot of extra weight and costs. The solution that is now increasingly being chosen is not to increase the current but the voltage, "says AutoWeek journalist Cornelis Kit, who focuses on technology.

The 48-volt network makes applications of things like an electric compressor possible. (Photo: Audi)

"Increasingly larger energy consumers on a car"

This makes applications of more powerful power generators possible. That works out well, since even the dynamo of a car cannot deliver much more than the aforementioned 250 ampere. In addition, the brands increasingly assemble larger power consumers. You can think of the electric compressor that Audi screws on the diesel engine in some models.

"You can see that there are already cars with electrically operating stabilizer bars. Such shock absorbers are also in the offing. Both require a lot of power. A 48-volt network is ideally suited for all these kinds of things," says Kit.

The electrically operating stabilizer bar on the rear axle of an Audi Q7. (Photo: Audi)

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