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Although the summer time is coming up slowly, it’s cold in Arjeplog – very cold. During the last winter testing of the eSprinter in January, the temperature hovered at around minus 30 degrees.
We are in a region that is close to the Arctic Circle, the Swedish Lapland. This is where the new eSprinter is to pass its winter endurance trials. Daimler is a regular guest at Arjeplog, it even has its own test track that puts our vehicles to the “ice-cold test”.
It’s eight o’clock in Arjeplog and the weather is still relatively humane at “only” minus four degrees so you don’t have to dress with as many layers as the days before. Everyone in the team came here with at least two caps, seven sweaters, three jackets and five pairs of gloves. This is the “running gag” for the entire time the winter test team is in action. And, at minus 15 degrees, the clothing inventory, worn on top of each other, is put to optimal use. Now and again, we unwillingly play “glove memory” when the other glove is accidentally left in one of the vehicles and then has find its owner again at the end of the day.
The eSprinter has a full schedule
The whole thing started after breakfast, with the proverbial crisp bread – the “moose sausage” was unfortunately already gone . The eSprinter was courageously waiting for another day of testing. We discussed what was to happen that day: what tests would be carried out, what routes, which engineer would go where to monitor the respective tests.
After the cold start of all vehicles, partly with ambient temperature, partly cooled down to minus 30°C in the cold cell, the colleagues split up to do their different tasks for the day. One of the engineers went to the frozen ice lake in Arjeplog, one of Sweden’s nearly 9,000 lakes, in order to test driving behavior and assistance systems.
Others took up their position at other points on the test track. Besides the driving, testing the charging process under extreme conditions is certainly just as important for the eSprinter – and must also be ensured under extreme cold conditions. This is done best in the aforementioned cold cells, where the batteries are cooled down to minus 30°C. At the end of the day, the results were collated and evaluated. We maintained continuous contact within the team, on the experiences that are made and things that can be improved.
The performance of the eSprinter was tested on gradients, among other things: – Can the eSprinter climb mountains easily even on icy roads? Yesterday, we drove up gradients of up to 15%, and the eSprinter also handled this challenge well even with a front-wheel drive. Let’s see how things turn out today. The journalists, who were exclusively invited, accompanied the team up to the “Galtis”, the highest mountain in the vicinity of Arjeplog.The eSprinter arrived at the top of the mountain without any difficulties – and even the steepest last passage was not a problem for our electric Large Van.
Since the batteries are located in the lower part of the vehicle, the center of gravity is very low.This ensures that the very high vehicle stands stable on the road and hardly wobbles even in curves.Besides the good results of our eSprinter, after the “summit climb” of the Galtis, we got one more reward : A Swedish-style picnic with – here we go again – crisp bread and sausages. And a breathtaking view of the lake panorama of Arjeplog.
Thermal management: Defrosting in minutes with heat pump and electric heater
All data, including the data of the “mountain test” was collected and checked for trends. Most of all, the so-called “thermal management” is very important. Later on, the eSprinter must function reliably and heat up as quickly as possible in daily use in cities, for example in the CEP sector (courier, express, parcel). This is because for our customers,time is money.
Therefore, the focal question in thermal management is: How can the driver’s cab warm up even faster at minus 30 degrees – and stay warm efficiently? As a comparison, when you get into a car with a combustion engine in the morning, it takes a bit longer for the engine to warm up and then for the interior to warm up.The electric car can react much faster, similar to an electric water heater, the heat is available almost immediately after the start without having to heat a massive engine block first. This means that it only takes a few minutes for the car to warm up and the windows to de-ice even at extreme temperatures.
When the system and the cabin reach a certain minimum temperature, the heat pump jumps in, which brings the residual heat available in the vehicle to a higher temperature level in a very energy-saving and simultaneously dynamic way, and it can be used to heat the cab. Briefly explained: As we already know, it is cold in the refrigerator because the heat is extracted from the refrigerator and is then released at the back at a higher temperature.
For practical purposes, the heat pump is a component that effectively pumps the heat to a higher temperature level. Conversely, it also works to get the car warm efficiently and to keep it warm.If you already know the time, at which the vehicle is to be warmed up, you can also store the information in the eSprinter for the “preheating”.The large van is then already warmed when you get in the car.
Charging at extreme temperatures
Since the vehicle is usually parked in this mode at the charging station, early heating can also have a positive effect on the range since the energy required for the heating is still drawn from the charging station and you can start off with a warm vehicle and a full battery.
The engineers tested and checked the eSprinter in Arjeplog up to and including mid-March, after which they returned to Stuttgart. But, as we all know, after the winter test is also before the summer test, which will be held in Spain again.There, the eSprinter will be exposed to the next temperature extreme of up to 40 degrees plus. Thermal management will also play an important role there, this time under the aspect of how the vehicle can be kept cool. Then we might play “sunscreen memory”.