Daimler explains how winter can affect the operations of its new range of electric heavy goods vehicles
Regardless of which cell technology is installed, if the battery temperature drops due to the low outside temperature, the internal resistance of the battery increases. Power loss rises as a result, and slightly less energy content can be used. In order to reduce negative impacts on the range in cold ambient temperatures, you can use a selectable charging mode to precondition the battery at the charging station. The battery is heated, which reduces the internal resistance and enables maximum power consumption.
Auxiliary climate control
On the Mercedes eActros, the use of auxiliary climate control means that If the vehicle is parked in cold or warm ambient temperatures for a longer period of time and the battery reaches its optimum temperature after many hours, the driver can set a an appropriate departure time by which the battery is heated, cooled or brought to the optimum temperature.
Without auxiliary climate control, the battery is automatically brought to the optimal operating window during operation. This occurs while driving or parking with the high-voltage on-board electrical system switched on.
At low temperatures, the heater switches on automatically during the charging process. The heating then warms the battery until current can flow again and the battery can be recharged. At temperatures below minus 19 degrees, the high-voltage battery system goes into self-protection mode in order to preserve the cell service life.
Charging time and range
The amount of time required to charge the battery is influenced by the ambient temperature with increased charging times associated with low temperatures. Charging times can also have a negative impact on the maximum available charging current of the charging station or the settings for the charging process in the onboard computer with regard to the charging limit.
Temperature also has an impact on the vehicle range and although it isn’t possible to estimate this impact precisely, there are many factors that play a role. If it’s very cold, it makes sense in any case to heat the cab and the battery. Also, the rolling resistance of the tyres and the oncoming aerodynamic flow of cold air are higher at low temperatures. Cold drive bearings also have greater resistance, which also increases consumption. However, this additional consumption evens out with increasing mileage and operating heat after having driven off. Overall, in wintry conditions, consumption will be higher at the start and improve during operation throughout the day.
Electric Vs Diesel
Intelligent thermal and energy management of the eActros ensures that both the drivetrain and the driver’s cab are energy-efficiently pre-conditioned to the correct temperature, even at low temperatures. Thanks to its smaller, high performance heating circuit, the eActros heats the cab faster than a diesel-powered vehicle. However, since the energy for this is taken from the batteries installed in the vehicle, thus reducing the range, auxiliary climate control is once again recommended at the charging station. For the time after having driven off, it is also advisable to use only the panel heaters, such as seat heating or the windshield heater in order to save energy.
As far as road performance is concerned, extensive winter testing of the vehicle has shown that the eActros can prove its worth on snow covered roadways. Especially thanks to the lower centre of gravity as a result of the positioning of the batteries, the eActros also has excellent traction in addition to its high vehicle dynamics. As with all Actros vehicles, the installed driver assistance and control systems can also contribute to safety.
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