Mercedes will be trailing its eActros with customers in Europe over the next couple of years. Picture: DAIMLER
Mercedes will be trailing its eActros with customers in Europe over the next couple of years. Picture: DAIMLER

Five years after we first saw it, the Mercedes-Benz Actros will launch in SA in a couple of months’ time.

With SA increasingly behind the curve when it comes to future transport solutions, it could be another five years before we see the recently unveiled electric eActros.

Daimler Trucks is synonymous with innovation leadership, allied to a realistic and pragmatic attitude, says Martin Daum, the Daimler board member responsible for Daimler Trucks and Buses. This is particularly true when it comes to electric mobility, he says.

"We now want to work together with our customers to move swiftly forward with the development of our Mercedes-Benz eActros to the point where it becomes a viable proposition in tough everyday operations — both technically and commercially" says Daum.

Innovation fleet

The company is beginning this process by creating an innovation fleet and will be supporting its testing in the day-to day logistics environment of its customers, he says.

"This will enable us to establish what remains to be done, in terms of technical matters, infrastructure and service, to make our eActros competitive."

Stefan Buchner, head of Mercedes-Benz Trucks says the company has developed a vehicle that has been configured from the outset for electric mobility. "Compared with our prototype, quite a few technical changes have been made: the power supply is now ensured by 11 battery packs in all — and wherever possible we have used proven components that are ready, or very close to ready, for use in series production."

These customers distribute goods via the road network — but in different sectors and categories. The palette ranges from groceries to building supplies and raw materials. The vehicles are being used by customers for tasks that would otherwise be completed by vehicles with conventional diesel engines.

The range of requirements means that the vehicles are fitted with a variety of bodies. According to need, refrigerated box bodies, tankers or tarpaulin sides are used. The drivers of the eActros are trained specially to work with the vehicle.

Batteries are stored in the centre of the chassis for increased safety and best weight distribution. Picture: DAIMLER
Batteries are stored in the centre of the chassis for increased safety and best weight distribution. Picture: DAIMLER

The pilot customers will be testing the vehicles in real-life operations for 12 months, after which the trucks will go out to a second round of customers for a further 12 months.

The basis for the eActros is provided by the frame of the Actros. Otherwise, the vehicle architecture has been configured specifically for an electric drive system, with a high proportion of specific components.

The drive axle, for example, is based on the ZF AVE 130 that has been used as a low-floor portal axle in hybrid and fuel-cell buses from Mercedes and is now being fundamentally revised for the eActros. The axle housing has been redesigned and is mounted in a higher position, increasing ground clearance.

The drive system comprises two electric motors located close to the rear-axle wheel hubs. The three-phase asynchronous motors are liquid-cooled and operate with a nominal voltage of 400V. They generate 125kW each, with maximum torque of 485Nm each. The gearing ratios convert this into 11,000Nm each, resulting in driving performance on a par with that of a diesel truck.

The maximum permissible axle load stands at the usual 11.5 tonnes. The energy for a range of up to 200km is provided by two lithium-ion batteries with an output of 240kWh. These have proved their worth in service with EvoBus, so can no longer be considered as prototypes.

The batteries are accommodated in 11 packs: three in the frame area and, the other eight underneath. For safety reasons, the packs are protected by steel housings. In the event of a collision, the mountings give way and deform, so diverting the energy past the batteries without damaging them.

High-voltage batteries

The high-voltage batteries do not just supply energy to the drive system, but to the vehicle as a whole. Ancillary components such as the air compressor for the braking system, the power steering pump, the compressor for the cab air-conditioning system and, where relevant, the refrigerated body, are also all electrically powered.

Discharged batteries can be fully recharged within three to 11 hours, assuming a realistic charging capacity of 20 to 80kW from a mobile charging device at a fleet depot.

With Volvo set to launch its electric trucks in 2019 and Tesla aiming to fulfil its promises of delivering its electric Semi, the days of the electric truck for distribution and urban usage are not far off. How far off they are for SA is another matter.