Mercedes Benz

In 1996 a first production vehicle followed. The Vito 108 E was equipped with a 420 kilogram zebra battery and had a payload of 600 kilograms. One battery charge sufficed to cover a maximum distance of 170 kilometers; the sodium-nickel chloride storage battery could be recharged at least a thousand times without any problem. Motive power was provided by a 40-kilowatt asynchronous motor that delivered its maximum output in the 2000 to 5000 rpm range. The nominal torque of 190 Nm already was available at very low revs, which is normal for electric motors. A five-speed transmission transferred the power to the front wheels. With this drive system the Vito 108 E attained a top speed of 120 km/h.

Unlike the Vito 108 E, the Vario Hybrid was equipped with two lead batteries 1.2 tons. To keep the cost down, no changes were made to the powertrain of the production diesel model, consisting of a 135 hp diesel engine (100 kilowatts) and six-speed transmission. Merely a 55 kilowatt three-phase asynchronous motor was added which in sensitive areas could provide the motive power by itself. It was good for a speed of 30 km/h and a range of 35 kilometers. Optionally, the electric drive and the diesel engine could work in tandem. In addition, the braking energy served to charge the batteries.

Another step forward was the Sprinter 311 with hybrid drive presented by the company in 2004 at the International Commercial Vehicle Show (IAA). This latest van with hybrid drive employs nickel-metal hydride (NiMH) or lithium-ion batteries with a capacity of 14 kWh. With NiMH batteries the entire electrical equipment weighs no more than 350 kilograms, with LI batteries only 160 kilograms. The electric motor develops 70 kilowatts. In this version the Sprinter attains a range of 30 kilometers in pure electric operation. Optionally, a version with 30-kilowatt motor and electrical equipment weighing 100 kilograms is available. In this case the capacity is three kWh, the range around three or four kilometers.

A particular advantage of the hybrid drive is that the vehicles can operate without problems not only in city centers but even in closed buildings. In the hybrid drive mode the batteries store the energy generated during braking and during downhill travel. This cuts diesel consumption by ten to 50 percent. Anyone operating the Sprinter mainly in the electric drive mode can recharge the batteries at night from a wall outlet. An optionally available plug-in function serves this purpose. If the driver floors the accelerator pedal, the booster function kicks in and the electric and diesel drives work in tandem.

Flexibility, efficient energy use and low emissions distinguish the hybrid Sprinter. On the other hand, the weight of the electric equipment detracts from the payload, and the batteries, particularly the light lithium-ion batteries, are still expensive. To make up for it, various countries encourage the purchase of hybrid vehicles with tax breaks and subsidies.