Mercedes Going Electric in High Profile Way with SLS AMG

In 1954, Mercedes-Benz introduced the milestone 300SL with its gull-wing doors and a fuel-injected engine under the hood. Both were ‘firsts’ from a major automaker. Fast forward 55 years to the recently announced Mercedes-Benz SLS AMG Electric. It also has gull wing -doors and an industry pacing technology, battery electric drive.

Mercedes-Benz refers to its ‘new Gullwing’ as a swing-wing model. The SLS AMG Electric is based on the V-8 powered SLS AMG supercar shown at the 2009 New York Auto Show that’s destined to replace the SLR McLaren, probably in 2011. The electric version could be a 2015 model.

These two zero-emissions sports cars were developed by Mercedes’ performance subsidiary AMG. Deutsche Accumotive GmbH & Co. KG, a joint venture between Daimler AG and Evonik Industries AG, provides the liquid-cooled, high-voltage lithium-ion battery packs for the electric variant. Power is supplied to four electric motors located near the wheels rather than wheel hub motors, which would add substantially to the car’s unsprung weight. One transmission is used per axle.

The four motors provide a total peak of 526 horsepower (392 kilowatts) and a whopping maximum torque of 648 lbs-ft (880 Newton meters) of torque. In comparison, the Mercedes-Benz SLS AMG with its 6.3-litre V-8 has 571 horsepower and 479 lbs-ft of torque. Both should be capable of accelerating from 0 to 62 mph (100 km/hr) in about 4 seconds.

As expected in a super car, handling should be excellent. Intelligent all-wheel-drive is used with torque vectoring that provides targeted acceleration of individual wheels. A low center of gravity is achieved by placing electric motors and transmissions low in the vehicle. Likewise, battery pack modules are located in front of the firewall, within the center tunnel, and behind the seats for a low center of gravity and balanced weight distribution. The 40 Ampere-hour, 400 volt battery has an energy content of 48 kilowatt-hours. Regenerative braking is used to charge the battery.

The AMG SLS Electric is not a retrofitted gasoline vehicle. The purely electric drive system was factored into the car’s design early in the concept phase, so installation of its electric drive components require no changes whatsoever to the swing-wing V-8 model's aluminum spaceframe body.