Not everyone’s convinced by electric cars, but the E-Cell may go a small way in helping to improve their image.
The SLS AMG E-Cell is to Mercedes-Benz, what the i8 is to BMW and the R8 e-tron is to the Audi. The electric drivetrain system has been in development since 2010, and the electrified gullwing-coupe is powered by four synchronous electric motors, which develop 525hp and 649lb-ft of torque. Acceleration from zero to 62mph has been timed at 4.0 seconds, so almost on par with the SLS AMG 6.3-liter V8 that develops 571hp and that can do the century sprint in 3.8 seconds.
The motors are mounted in the chassis near each wheel, and torque vectoring from the individually-driven wheels helps to optimize the vehicle's cornering properties and significantly benefits driving dynamics, handling, driving safety and ride comfort. In addition to aluminum, carbon-fiber reinforced plastic (CFRP) has been used throughout, due to its high strength and 30 percent weight-saving over the metal. The battery is housed inside the carbon-fiber monocoque to both increase safety and allow the center of gravity to remain low and keep weight distribution to remain even.
To give you an idea how light the fibers are, Mercedes explains the each fiber is a tenth of the thickness of human hair, and if one was long enough to reach the moon it would weigh just 25 grams. The E-Cell is an engineering project rooted in F1 that extends beyond its carbon-fiber unibody structure. For example, the carbon ceramic brake roots are very powerful, resistant to fading, and also help keep the car's weight down. The standard SLS double wishbone vertically-arranged system is replaced by racing-style horizontal pushrod shocks, as the FWD electric drive system required a different axle setup.
Kinetic Energy Recovery Systems known simply as KERS are common to F1 now, where kinetic energy is turned into heat and electric energy upon braking and used to give a boost of power at certain points during a lap. In the liquid-cooled, lithium-ion, high voltage 48kWh battery at the heart of the SLS E-Cell, energy is recuperated when braking, just like the F1 KERS. Mercedes expects to launch the E-Cell as part of a small series-production run in 2013, when the naked drive system seen here will be wrapped in an SLS AMG body.