Detroit show: Mercedes flicks switch for electric SLS
BY JAMES STANFORD | 11th Jan 2011
The company first presented the AMG-developed electric SLS E-Cell gull-wing midway through last year as a concept car but was not ready to commit to a production plan.
This week at the North American International Auto Show, Daimler AG board chairman Dieter Zetsche said the bold electric supercar would be available in showrooms in just two year’s time.
The announcement comes just weeks before the 125th anniversary of the first car, made by Gottlieb Daimler and Karl Benz.
“The Mercedes-Benz SLS AMG E-Cell is the most technically advanced super sportscar in the 125-year history of the automobile and shows just how fascinating electro-mobility can be,” said Mr Zetsche.
“Our customers will be able to order it from their Mercedes-Benz dealers from 2013 onwards.”
The SLS is normally powered by a 6.2-litre V8 that generates 420kW of power and 650Nm of torque.
For the E-Cell concept, the fossil-fuelled engine is replaced by four electric motors placed at each corner of the car, close to each wheel but not inside them.
This solution was chosen over the in-wheel motor system used by some other electric carmakers because it reduces the amount of un-sprung mass (the weight of components not supported by the vehicle’s suspension) and therefore does not compromise the vehicle’s handling.
The electric motors generate a combined power output of 392kW, while the torque tally hits an impressive 880Nm, which is available almost instantly.
This is enough to sling the E-Cell supercar from 0-100km/h in 4.0 seconds, just 0.2s slower than its V8-powered sibling.
The E-Cell concept car has a 400-volt liquid-cooled battery pack made up of 324 lithium-ion polymer cells containing 48kWh of energy and benefits from regenerative braking.
Given the car’s size, the battery pack’s modules are located in the engine bay, down the centre transmission tunnel and behind the seats.
Mercedes said it mounted the battery modules, as well as the two transmissions that control the wheels, very low in the vehicle to lower the centre of gravity for improved handling.
The front suspension had to be changed, though, from a double-wishbone set-up to a multi-link system using pushrod dampers with horizontal struts to accommodate the battery pack.
While the SLS E-Cell shows Mercedes is serious about electric cars, it is still keen to promote its fuel cell technology.
Dr Zetsche announced at the Detroit show that Mercedes will circumnavigate the world with its first production fuel cell vehicle, the B-class F-cell.
It says the idea behind the drive is to demonstrate that it is useable everyday technology while also calling on governments around the world to press for a fast roll-out of a hydrogen fuel infrastructure.
The 125-day road trip will start on January 30 and run through 14 countries, including France, Spain, Portugal, China, Australia, the US and Russia.
“With this unique circumnavigation of the world, we are emphasising the high level of technical maturity of our electric vehicles with fuel cell,” said Mercedes research and development chief Thomas Weber.
“Such an undertaking would not be possible using purely battery-powered electric vehicles.”“Today, as with the invention of the automobile 125 years ago, the issue of a corresponding fueling infrastructure arises. But I am confident that, together with all of the parties involved, we will find a solution that enables us to fully exploit the tremendous potential of this technology.”
