Mercedes-Benz will start production of its all-electric eActros 19 and 27-tonne GVW trucks in October, but warns the success of the concept depends upon the creation of a business-oriented electric vehicle eco-system, which it would facilitate via an eConsulting team.
Battery-powered, the eActros uses paired asynchronous motors in the rear axle, which incorporates a two-speed gearbox. Containing the driveline entirely within the axle not only liberates more space for batteries but also reduces mechanical losses as there is no power-sapping differential gear. The motors recover energy from braking, with five different retardation stages available.
Key claimed performance figures for the eActros are a range of up to 400 km on a standard charge, and, thanks to an increased one-tonne allowance for electric trucks, comparable payload with diesel 18 and 26-tonners. Front-end cost is three times that of the diesel equivalent, but operators can take the gamble out of the purchase by opting for an operational lease giving a guaranteed residual value.
A service contract to cover all workshop maintenance and repair costs is also available, and technical data from the trucks, covering everything from battery status to tyre pressures, can be monitored remotely and used to schedule workshop time.
Director of Mercedes-Benz Truck Europe and Latin America, Karin Rådström, told Transport Operator that the total cost of ownership of the eActros should be compatible with that of a diesel by 2025, but this was dependent upon many external factors including energy prices and government support.
Mercedes has created eConsulting teams to help operators navigate through these choppy waters. These will assess the routes the customer plans to run the truck on to ensure its suitability, review any government subsidies or incentives that may be available, and assist in the process of integrating the etrucks into the existing fleet and optimising the total cost of ownership.
Customers can also get help from Mercedes partners Engie and EVBox Group with the installation of charging infrastructure and software at their depots.
Trucks can be specified with three or four battery packs, each of around 150 kW/h capacity. These are protected by an aluminium structure incorporating impact-activated isolation switches. Manual isolation switches are also provided for use by maintenance and emergency crews. Within a few seconds, any residual current within the high-voltage system outside the batteries is removed. Battery temperatures are also constantly monitored, even when the vehicle is switched off.
A conventional electrical system, using two 12v batteries, powers lights and other accessories, including power-steering and the air-compressor. This is recharged via a DC/DC convertor from the traction batteries, and the lights and other systems can remain operational even when the high-voltage system is isolated. The electrical system can also power a cargo refrigeration unit for temperature-controlled transport.
Many key components are stored in an easily-accessible undercab compartment fitted to the space that would be occupied by the engine on a diesel truck. These include the heat exchanger, water pumps, cab electrical circuits, DC/DC converter, valves, and the two low-voltage batteries, and this helps optimise weight distribution across the axles.
Mercedes uses the proprietary Combined Charging System (CCS). The eActros can be charged with up to 160 kW: when connected to a regular 400A DC charging station, the battery packs need little more than an hour to charge from 20 to 80 per cent. To charge the eActros, a CCS Combo-2 type connector is required and the charging station must support DC charging.
The eActros employs the full suite of Mercedes driver support systems including MirrorCams and brake assist and turn assist, plus there is a wealth of information concerning the state of the batteries, power consumption, and projected range available to the driver via the Multimedia Interactive Cockpit.
Maximum output of the drive axle is 400 kW, with 330 kW continuously available. Cab noise is half that of a diesel truck, and vibrations are considerably reduced.
Although early versions of the truck used a ZF axle originally developed for city buses, Mercedes appears to have taken production of this in-house with components being produced in Gaggenau for assembly in Kassel. The battery packs will be assembled from components imported from China in Mannheim.
Final assembly of the trucks will take place at the Mercedes truck factory in Wörth, on the same production line as the diesel trucks, although high-voltage equipment will be installed away from the main production area.
An electric version of the Econic municipal vehicle will follow the launch of the eActros. Hydrogen fuel cell versions of eActros won’t appear until 2024. Karin Rådström explained that the fuel cell would complement, rather than replace, the battery electric technology.
“The fuel cell offers a bit more range, but uptake depends on available infrastructure,” she cautioned.