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Forty years ago, Mercedes-Benz presented the prototype 307 E, a 100% electric experimental van, at the Envitec Show in Düsseldorf. It was February 1980. In October of the same year, the vehicle was also making a presence at the Drive Electric 80 Show in London. But this was not the brand's first utility prototype with a 100% electric drivetrain because eight years earlier, Mercedes-Benz had developed the LE 306, an experimental vehicle of which 60 were produced. Already, the manufacturer realized, after more than 900,000 kilometers of testing aboard the LE 306 until 1979, that electric traction was ideal for travel in urban areas. For the next prototype, the 307 E, a series of full-scale tests was also carried out in the early 1980s. The Federal Ministry of Research and Technology (BMFT) tested 10 electric vans in a strictly urban setting in Berlin and the German post office (Deutsche Bundespost) has had 22 307 E vans spread across the city of Bonn for mail delivery over five years. These two practical tests led to the same conclusions about the usefulness of electric technology for transporting goods in urban areas, a finding that is still valid today.
A little bit of technique
Photo Credit – Daimler AG
Obviously, the main problem with electric vehicles 40 years ago was the performance of their batteries, which still consisted of lead and acid. A peculiarity which made them not very powerful while greatly limiting their lifespan. Lithium-ion technology is also currently experiencing its limits, but is still showing much better performance.
The Mercedes-Benz 307 E prototype was based on a TN series utility vehicle, also known as the “T1”. It loaded under its floor two rows of lead-acid batteries each supplying 90V (180V in total) between its two axles, themselves spaced 3.35 meters apart. The utility vehicle offered a cargo space that was no less bulky than on the equivalent model with combustion engine. Its payload was 1.45 tonnes and its range was only … 65 km at a constant speed of 50 km / h. Compared to the 184 km of range of recent Mercedes eVito and eSprinter, the value is not that ridiculous, knowing that 40 years separate them.
The 307 E's direct current “shunt” motor developed a power of 30 kW, or barely 41 hp, enough to reach a maximum speed of 70 km / h. You should not want to engage in a climb of more than 20% under penalty of staying put! A true research laboratory, the 307 E allowed engineers to test other technologies such as the “route planner”, a precursor of GPS that takes into account information on traffic jams to potentially change lanes. A body of fundamental research from which current Mercedes-Benz vehicles are still reaping the benefits.