Bus companies place the same demands on electrically powered buses as on their counterparts with conventional diesel engines. Even in difficult weather conditions such as cold, ice and snow, the vehicles have to do their job reliably. Against this background, the current winter tests of two near-production Mercedes-Benz eIntouro vehicles in Rovaniemi, Finland, once again proved to be important endurance tests. Under extreme climatic conditions such as snowy and icy carriageways, biting winds and temperatures down to minus 30 degrees, the development and testing team put the first battery-electric intercity bus from Daimler Buses through its paces in order to probe for further optimisation measures.
All new bus types from Daimler Buses undergo an extensive test routine before the start of series production, which includes safety tests and load tests as well as driver tests under extreme heat and in extreme cold.
Battery-electric intercity bus tested under the toughest conditions at the Arctic Circle
During the trip to Finland, the engineers closely examined all the functions and systems of the two eIntouro in practice. For example, the coordination of the drive control and the central drive module were also part of the team’s tasks, as was the gearshift coordination of the three-speed transmission integrated into the central drive module and the optimisation of the brake management, in which the recuperation of the electric motor plays a decisive role.
At the same time, the eIntouro was able to prove its long-distance capability during the winter test drive: test engineers from Daimler Buses drove the eIntouros the 3,000-kilometre route from Neu-Ulm to Finland and back again on their own wheels. They only used publicly available charging infrastructure for recharging. The quick-charging capability of the batteries enabled short charging breaks and a swift continuation of the journey.
Focus on energy management, charging capability, electric drivetrain and brake system at sub-zero temperatures
On site in Rovaniemi, the experts paid particular attention to the behaviour of the batteries and the electric drivetrain of the eIntouro in adverse weather conditions. For this purpose, they checked, among other things, the cold-starting characteristics, the charging capability of the high-voltage system at extremely low temperatures, and the cold protection of the drive components, software and interfaces. In addition, the thermal and energy management systems were tested intensively. Both ensure that the batteries and the drivetrain, as well as the passenger compartment and the driver’s workplace, are kept at the right temperature, correctly and energy-efficiently, even at low temperatures.
The winter test also included numerous tests on driving and braking characteristics on surfaces with varying grip. Among other things, these tests were used to coordinate all the safety-relevant systems, such as ESP and ASR, and the driver assistance systems.
Results prove operational capability even in winter conditions
Martin Teigeler, Head of Product Engineering Daimler Buses: “Our extensive tests on the behaviour of the batteries and the electric drivetrain at extreme sub-zero temperatures, and on the handling characteristics of the vehicles on polished icy roads or in slush did not simply yield important findings for further optimisation. They also showed that the battery-electric eIntouro is fully operational even in winter conditions.”
Mercedes-Benz eIntouro: first electric double earner from Daimler Buses
The Mercedes-Benz eIntouro is based on the familiar diesel-powered high-floor Mercedes-Benz Intouro bus, but is equipped with a battery-electric drive instead. As a result, Daimler Buses is now able to switch to electric mobility for classic interurban routes, school buses and shorter long-haul trips for the first time. In addition to the 12.18-metre-long eIntouro, the eIntouro M with a length of 13.09 metres will also be available. This allows seating variants from 50 up to a maximum of 63 seats. For the first time in a European bus, software updates can be installed in the eIntouro “over the air” without a workshop visit.
SOURCE: Daimler Truck
