REEV stands for Range-Extended Electric Vehicles. The idea behind this technology, which involves charging the high-voltage (HV) battery of electric cars using a combustion engine while driving, thereby increasing the range, is not new. However, MAHLE is now taking this technology to the next level. With MAHLE components in the system, the capacity of the HV battery can be reduced, which not only lowers costs but also shortens charging times on longer journeys. Demand for this technology is growing, especially in China. With the diversity of drive technologies proclaimed by MAHLE, this technology could accelerate climate protection, strengthen the European automotive industry, and preserve jobs there.
Up to 1,350 kilometers with an electric car on a single charge! That's something for drivers who are not yet so open to electric vehicles because of their (apparently too low) range. To give stalling e-mobility a boost, range extenders such as the MAHLE range extender system are a good approach to accelerating the spread of electric vehicles.
The principle is clear: the electric car runs purely on electricity until the HV battery is almost empty. Then the range extender kicks in and recharges the battery to supply the electric motor with power. Depending on the vehicle and battery size, this allows for up to 1,350 kilometers in WLTP (Worldwide Harmonized Light Vehicles Test Procedure). The range extender's combustion engine is completely decoupled from the wheel drive—in contrast to the classic plug-in hybrid. And when it is powered by renewable fuels, it runs almost climate-neutrally.
The range extender system consists of a supercharged high-tech combustion engine with MAHLE Jet Ignition, direct injection, and Miller valve timing. The efficiency of this compact powerhouse is more than 42 percent. It is a scalable engine platform for a wide range of vehicles—from 30 kW to 120 kW, as a 2-, 3-, or 4-cylinder (500 cm³ per cylinder).
The second main component of the range extender is an efficient HV generator with an integrated cooling system. It converts mechanical energy from the engine into electrical energy. At the heart of the 800-volt generator is a permanently excited electric machine with a peak efficiency of more than 97 percent and a rated continuous output of 85 kilowatts. One of its special features is the effective direct rotor cooling via the cooling circuit, which, among other things, significantly reduces the need for heavy rare earths.
"Small, lightweight, easy to integrate, and resource-efficient—the range extender with MAHLE components is a compact, efficient powerhouse," says Dr. Marco Warth, head of Group Research and Advanced Engineering at MAHLE.
The technology kit for range extender engines is supplemented by specially developed engine components such as pistons and valves.