Mercedes-Benz and AMG have been teasing us with the prospect of an all-electric supercar since the SLS AMG E-Cell concept broke cover in 2010. Now at the Paris Motor Show, Mercedes has presented the public with an all-electric SLS that's set to become the fastest production electric supercar in the world when it hits the road next year.
In designing the Mercedes-Benz SLS AMG Coupé Electric Drive, Mercedes-AMG took a few crib notes from the Formula 1 racing world. Not only does the body and drivetrain use F1 technology, the designers also adopted the racing maxim of starting with the the drive engineering and working their way out. For the SLS, the electric drivetrain is the focus. The battery is located within a carbon-fiber monocoque that acts as the cars spine around which the aluminum spaceframe body is built. To keep the center of gravity low, the battery compartment is close to the ground and spread along the length of the car to keep the weight distributed.
The profile shows the SLS’s heritage with echoes of the Mercedes-Benz SL marque of the 1950s. There’s the same balance between cab and body that says that this thing moves like a stabbed rat. Never mind that when you lift that landing-deck sized bonnet you'll be greeted by a set of carbon fiber panels instead of a V8 engine.
The interior has a definite racing cockpit feel to it and for all its stitched black leather and carbon-fiber trim elements, the atmosphere is one of of German engineering efficiency. This being an electric, the instrument cluster doesn't have a rev counter. Instead, there’s a power display that goes on about power requirements, recuperation status, transmission modes and battery charge. There’s also high-speed internet access and a range of system data displays that will tell you more than you probably want to know about the car’s status and performance.
But the center of all this is what makes the SLS go. Instead of a massive petrol engine, there are four synchronous electric motors weighing 45 kilograms (99 lbs) each turning at 13,000 rpm. Combined they put out 740 bhp (552 kW) and 1000 Nm (727 foot pounds) of torque. Taking full advantage of the fact that electrics have maximum torque when taking off, the SLS does 0 to 100 kilometers per hour (62 mph) in 3.9 seconds. Top speed is 155 mph (250 km/h), which is pretty good while hauling 548 kilograms (1,208 lbs) of lithium-ion batteries. The maximum range of the SLS is 250 kilometers (155 miles).
This quartet of motors are linked selectively by an axially-arranged transmission design for something called “AMG Torque Dynamics.” This allows individual control of the electric motors and selectively distributes the forces for each individual wheel. which can be individually driven and braked. This improves handling and performance, especially on corners where battery-heavy supercars have a hard time of it. There are also three transmission modes - Comfort, Sport and Sport Plus.
The Mercedes-Benz SLS AMG Coupé Electric Drive’s uses Formula 1 high-voltage lithium-ion batteries rated at 60 kWh and 400 volts and were developed by Mercedes-AMG GmbH in Affalterbach, Germany and Mercedes AMG High Performance Powertrains Ltd. in Brixworth, UK. The twelve modules of batteries are liquid cooled and have a heating system to keep them at an optimum temperature in cold weather. While driving, the SLS increases range by charging the batteries through electrical recuperation during deceleration. At home, the SLS charges in 20 hours from a standard mains outlet and can charge in three hours with an optional 22 kW wall box.
Of course an electric supercar isn't going to sound as fearsome as its ICE powered brethren, and since this isn't any fun, Mercedes AMG has installed eleven loudspeakers in the SLS that makes it sound like a “real” car; all coughs and growls tuned to the appropriate driving conditions. The Mercedes-Benz SLS AMG Coupé Electric Drive may make a satisfactory bellow when roaring down the Autobahn, but bear in mind that its prerecorded.
The Mercedes-Benz SLS AMG Coupé Electric Drive hits the market in 2013. The price in Germany will be 416,500 euros (US$ 535,869). And if the "AMG electricbeam magno" matt paint finish doesn't appeal, there are five other colors to choose from.
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