A 2-seat electric car concept recently unveiled by a major automotive supplier — best known for pistons and other power-cylinder components — is capable of making inner-city jaunts for up to seven days on a single battery charge.

Mahle showed its MEET (Mahle Efficient Electric Transport) technology demonstrator during AutoMobili-D activities at the recent 2019 North American International Auto Show in Detroit.

“This concept is really a proof-point for Mahle’s commitment to meet the demands of future urban mobility,” said Dr. Jorg Stratmann, CEO of Germany-headquartered Mahle. The supplier’s wide portfolio includes powertrain and HVAC technologies for electrified and internal combustion engine (IC)-powered vehicles.

MEET’s propulsion power is derived from two Mahle Interior Permanent Magnet (IPM) synchronous motors. Although engineered for inner-city use, the IPM can hit speeds up to 100 km/h (62 mph).

The car’s traction drive system comprises a 48-volt twin-power drive unit with torque vectoring capability. Because separate motors drive each rear wheel, a differential isn’t needed. Peak power output for each motor is 30 kW (40 hp) and 110 N·m (81 lb·ft). MEET’s central axle transmission has an 11:1 ratio.

When the 48-volt twin-power drive is paired with a 15.4 kWh lithium-ion battery pack, the concept demonstrator provides an estimated 120-mile (194-km) driving range. That translates to more than 13 miles (20 km) a day for a week of urban-only driving on a single charge, Mahle offered.

The city car is designed as an all-weather commuter. “As in all vehicles with a purely electric powertrain, one of the biggest challenges with respect to energy storage is heating the interior, particularly in the winter,” Dr. Stratmann said, noting the importance of thermal management.

A thermoelectric coolant-to-coolant heat pump extracts waste heat from the electric motor, the power electronics and the battery for use by the vehicle’s HVAC system. Inside the car, thermoelectric heating and cooling elements — located within the instrument panel, door trim, and armrests — can be activated to provide surface heating and cooling in direct proximity of the occupants.

In comparison to a positive temperature coefficient heater, the thermoelectric heat pump can extend the car’s driving range by 30% with an ambient temperature of 0 degrees C in Europe's recently-adopted Worldwide Harmonized Light-Vehicle Test Procedure (WLTP) and an estimated 50% based on Mahle’s simulated and actual urban test drives.

The MEET and its modular drive unit, which also can be used as an e-axle for a 48-volt hybrid system, serves as a precursor to other Mahle demonstrator concepts. “There is more to come,” Dr. Stratmann said. Continue reading »