Range and charging infrastructure problems faced by electric heavy-duty commercial vehicles continue to be one of the most important issues on the agenda of the sector. To address these challenges, German automotive supplier Mahle has developed a compact electric truck range extender system that replaces part of the battery.

This new technology aims to increase the total range of electric trucks to over 800 kilometers. In a unique way, the system uses an internal combustion diesel engine to achieve this range increase.

Compact Generator System Instead of Battery

Designed by Mahle, the system can be installed directly in the space allocated for the truck’s battery. The company integrates the internal combustion engine, high-voltage generator, fuel tank, AdBlue tank, exhaust gas treatment system, and cooling unit into a single compact body.

This structure replaces approximately one-third of the truck’s existing battery capacity. Thanks to the miniaturization of the battery modules, the vehicle’s rear axle load is reduced by approximately 400 kilograms, and its total weight by approximately 600 kilograms.

In this structure, which Mahle describes as an EREV, or range-extending electric vehicle, the wheels are always driven by an electric motor. When the power in the battery decreases, the internal combustion engine kicks in, generating electricity by running the generator instead of transferring mechanical power to the wheels.

Similar in principle to plug-in hybrid vehicles, the drive system remains entirely electric. According to the company, the battery provides approximately 400 kilometers of driving range, while the range-extending system offers an additional 400 kilometers of range.

High Efficiency and Low Emission Target

At the heart of the range extender is a high-voltage generator with a constant output of 110 kW and a maximum output of 130 kW. The generated electricity is directly transferred to the electric powertrain, especially on long and demanding routes or when the vehicle is fully loaded.

Thanks to its innovative oil cooling system, the generator achieves a power density of over 7 kW/kg. For the thermal management of the system, 48 kW of high-temperature and 15 kW of low-temperature cooling capacity is provided.

Despite the addition of an internal combustion engine, Mahle states that the system offers a significant emission advantage compared to conventional diesel trucks. According to assessments made under real-world conditions, a truck using this system can have CO₂ emissions approximately 80 percent lower than conventional diesel trucks.

The engine is also designed to run on renewable fuels such as HVO100 biodiesel. Mahle says that using these types of fuels can reduce the vehicle’s CO₂ emissions to almost zero.

The company will showcase this range extender system at the IAA Transportation trade fair in Hanover, from September 15-20. Mahle will also introduce its new MCT E-Motor technology for heavy commercial vehicles, which is free of rare earth elements and offers 370 kW of power. Do you think such hybrid solutions should become widespread in electric trucks?