Daimler Vito E-Cell
We take a look at Daimler’s first mass-produced electric commercial vehicle, Vito E-cell van
- Published in Vehicle Development.
City worker
The Vito E-Cell has enough range and power to function in the city
Charging and range are the two key issues for electric vehicles and their potential to provide a real alternative to the internal combustion engine. People use cars for mobility, whether that means nipping out to the local shops or a cross-country trek to see relatives. Battery power isn’t always able to meet those demands because vehicle ranges are too short and recharging times too long.
In the confines of a city, however, the benefits become clearer, especially if you use the technology for commercial vehicles. Many smaller delivery vans travel less than 80km a day – well within battery range – and fleets have easy access to charging points at their depots.
Daimler is building a fleet of 100 electric vans this year, which will grow to more than 2,000 by the end of 2011. The Vito E-Cell, based on the OEM’s long-wheelbase Vito panel van, uses a permanent synchronous motor that produces 70kW of peak power, 60kW continuous power and 280Nm of torque. This is coupled with a 36kWh lithium manganese oxide battery.
The vehicle is said to have a maximum range of 130km, though Daimler suggests the average driver will travel only 50km-80km a day.
Andreas Pohl, project co-ordinator for battery-electric vehicles, says: “Passenger cars and commercial vehicles have different certification processes but in general all of our electric vehicles – such as the electric Smart and the Vito E-Cell – work on the same level. Fundamentally there is no difference between the two technologies.”
The base technology may not be far removed from passenger vehicles but commercial vehicle usage is quite different. How often do you have to transport hundreds of kilograms of goods in your car?
The Vito E-Cell can carry a payload of up to 900kg, close to the 980kg capacity of the combustion engine versions. It’s quite an achievement given that the electric powertrain weighs close to 900kg itself, largely because of the battery.
“The weight of the battery unit is roughly 500kg, but that includes the frame round the battery, the management system, and the water cooling unit. The battery itself weighs below 300kg,” says Pohl. Reducing that weight further will improve the payload capacity, and Pohl and his engineers are already focused on the problem. “Right now the powertrain uses a water-cooled system but we’re working on an air-cooled system that will reduce weight by roughly 60kg,” he says. Energy recuperation will also help, and here Pohl is ambitious: “Our goal is to achieve roughly 40% energy recuperation over the working day, which we could recharge the battery with.
“It depends on customer behaviour, it depends on the route, it depends on battery conditions. It’s a huge target, but we have a big 36kWh battery and if we could achieve our target of 40% then we could reduce the size of the battery.” The first E-Cell vans off the production line had no brake engery recuperation because the electronic stability control required had not been installed. So, on my drive through the streets of Stuttgart there was no indication of how that amount of recuperation might feel. The system used on the Mini E was so strong that the car slowed quickly once your foot left the accelerator pedal, without applying the brake. Its system could achieve 20% recuperation. The Nissan Leaf compact electric car can achieve 30%.
