A Closer Look at the Mercedes Benz GLC F-Cell Technology

author: Eric Walz   

LOS ANGELES - Mercedes Benz was among the many automakers at this year's Los Angeles Auto Show. At the event, Mercedes showed off its entire lineup, including the GLC F-Cell compact SUV. The GLC F-Cell is the world's first electric vehicle with both fuel-cell and battery powertrain.

Also for the first time, a fuel-cell-operated electric car is using a lithium-ion battery as an additional energy source that can be externally charged by means of plug-in technology.

The GLC F-Cell has two energy sources to drive the electric motor - with zero emissions. The long range, short refuelling time, an output of 147 kW (200 hp) and the latest generation of assistance systems with powertrain-specific features demonstrate, based on the models on display, the GLC F-CELL will be a family-friendly electric vehicle for everyday driving.

For this world first, the Mercedes-Benz engineers cooperated closely with partners from the Daimler competence network to develop a completely new fuel-cell system. Compared with the Mercedes B-Class F-CELL, which has been on the market since 2010, the overall F-Cell drive system offers around 40 percent more output.

The fuel-cell system is around 30 percent more compact than before, can for the first time be housed entirely in the engine compartment and is installed on the usual mounting points like a conventional engine.

The lithium-ion battery in the preproduction vehicles on show has a gross capacity of 13.8 kWh and additionally serves as an energy source for the electric motor. For the first time, it can also be charged externally using plug-in technology.

Just like the drive motor, the powerful storage battery is space-savingly installed in the rear of the SUV. Using the 7.2 kW onboard chargers, it can be conveniently charged from a standard household power socket, a wallbox or a public EV charging station. The charging time is around 1.5 hours if the full capacity is used.

The Hydrogen Tanks

Two carbon-fiber encased tanks built into the vehicle floor hold around 4.4 kg of hydrogen. Thanks to globally standardised 700 bar tank technology, the supply of hydrogen can be replenished within just three minutes, which is about the same amount of time it takes to refuel a car with an internal combustion engine.

The Drive System

The F-CELL vehicles on show at the IAA are powered by an asynchronous machine with an output of 147 kW (200 hp) and a torque of 350 Nm. The electric drive requires no driveshaft this makes room for one of the two hydrogen tanks, while the second tank is installed under the rear seat bench.

The GLC has four operating modes. In HYBRID operating mode, the vehicle draws power from both energy sources. Power peaks are handled by the battery, while the fuel cell runs in the optimum efficiency range. The intelligent operating strategy allows both energy sources to be used simultaneously.

In F-CELL mode, the state of charge of the high-voltage battery is kept constant by the energy from the fuel cell. Driving almost exclusively on hydrogen is the ideal mode to keep the electric range in reserve for certain driving situations.

In BATTERY mode, the GLC F-CELL runs all-electrically and is powered by the high-voltage battery. The fuel-cell system is not in operation in BATTERY mode. This is the ideal mode for short trips.

In CHARGE mode, charging the high-voltage battery has priority, for example in order to recharge the battery for the maximum overall range prior to refuelling with hydrogen. This mode also creates power reserves for uphill or very dynamic driving.

In all operating modes, the system features an energy recovery function, which makes it possible to recover energy during braking or coasting and to store it in the battery.

For production the vehicle, Mercedes turned to its global partners. The centrepiece of the technology, the fuel-cell stack, was developed in Vancouver, Canada, together with partner Ford in the Automotive Fuel Cell Cooperation (AFCC) joint venture.

Production takes place directly nearby at Mercedes-Benz Fuel Cell (MBFC). The entire fuel-cell unit and the hydrogen storage system were developed by the Daimler subsidiary NuCellSys in Kirchheim/Nabern in Baden-Württemberg.

The Daimler parent plant in Untertürkheim is responsible for fuel-cell system assembly, also in Nabern. The hydrogen tank system, consisting of carbon-fibre-encased tanks, is produced at Daimler's Mannheim plant, while the lithium-ion battery comes from the wholly owned Daimler subsidiary ACCUMOTIVE in Kamenz, Saxony.

A nationwide infrastructure for charging and refueling is essential for the success of EVs and fuel cell powered vehicles. The growth of charging and hydrogen filling stations is proceeding around the world. Together with its partners in the H2 Mobility joint venture, Daimler has already drawn up a concrete action plan.

The network of H2 filling stations is scheduled to reach 100 by the end of next year. By 2023, there will be a network of up to 400 hydrogen filling stations. Similar infrastructure projects are being promoted in Europe, the USA and Japan.

Eric Walz

Originally hailing from New Jersey, Eric is a automotive & technology reporter covering the high-tech industry here in Silicon Valley. He has over 15 years of automotive experience and a bachelors degree in computer science. These skills, combined with technical writing and news reporting, allows him to fully understand and identify new and innovative technologies in the auto industry and beyond. He has worked at Uber on self-driving cars and as a technical writer, helping people to understand and work with technology.