Case Study

Smart Electric Drive

Zytek converted an initial 100 smart fortwos to fully electric versions at their production facilities in Fradley, Staffordshire. These vehicles took part in a market trial by selected British customers as lease vehicles from 2007 to 2009.

The drivetrain installed in the smart electric drive utilizes state of the art brushless DC motor technology that is designed and manufactured in house by Zytek. The award winning innovative drivetrain design integrates the electric motor, power and control electronics, into one compact assembly with only three connections: water, High voltage(300V) and low voltage (12v).

The smart fortwo ev sets a new benchmark in the electric vehicle sector, the 55kW drivetrain producing a top speed of 120km/h. 12 kilowatt hours per 100 kilometres gives it a range of 110 kilometres. These figures indicate that the smart fortwo ed is a vehicle that is ideal for short journeys in urban traffic.

It only takes three and a half hours to charge the battery from 30 to 80 percent of its capacity. An empty battery can be fully charged in no more than eight hours, for example overnight.

The electric engine is located in the rear, installed into the three engine mounts exactly where the combustion engine would be in a conventional vehicle. The transmission, which has been locked in second gear, is likewise in the rear of the car. The smart fortwo ed therefore does not need the smart fortwo’s gearshift knob, since it only uses one forward and one reverse gear.

The charge level indicator for the battery is where the rev counter would be in other vehicles in a central position on the instrument panel, together with the analogue clock. But that’s all that has changed. The interior and the luggage compartment are just as spacious as before, and even the smart fortwo ev’s power storage unit – a sodium-nickel chloride battery manufactured by MES- DEA of Switzerland, is positioned centrally in the car’s underbody.

The success of the UK trials led to the next generation smart 451 electric drive rolling off the production line from October 2009 through to April 2011. During this time over 2,000 smart EDs were produced at a dedicated Zytek facility at the smart fortwo assembly plant in Hambach, France.