The Gullwing Goes Electric
By Gizmag Team
The Audi e-tron has been at the top of our list of awesome electric cars for some time. Now there's a new contender — the SLS AMG E-CELL. Mercedes-AMG hinted at the possibility of an electric drive SLS gullwing last year and has now rolled-out a prototype which looks set for small series production. Along with a very hard to miss fluorescent "AMG lumilectric magno" paint job, the prototype features four electric motors positioned near each of the wheels which produce 392 kW and 880 Nm of instantaneous torque and acceleration of zero to 100 km/h in 4 seconds — just 0.2 seconds under the performance of the 6.3-litre V8 SLS AMG.
Instead of hub motors, the gullwing SLS E-CELL uses four compact electric motors positioned near to the wheels (two for each axle) to reduce unsprung weight. Each motor achieve a maximum rpm of 12,000/rpm for a combined output of 392 kW.
The electric-drive SLS retains the lightweight aluminum spaceframe as its petrol driven sibling but the suspension has been altered to accommodate the electric drivetrain. The double wishbone axle makes way for an independent multilink suspension with horizontal damper struts operated via separate push rods and transfer levers.
In addition to regenerative braking in the motors, the SLS E-CELL gets over-sized, carbon fibre-strengthened ceramic brakes which reduce weight and improve stopping distance and steering response through high speed bends.
The prototype is powered by a liquid-cooled, 48 kWh lithium-ion battery pack with a capacity of 40 Ah (at 400 V). The three battery modules are positioned in front of the firewall, in the center tunnel and behind the seats which keeps the center of gravity low for better handling.
Power is delivered to the wheels via an electronic control system that converts the direct current from the high-voltage battery into three-phase alternating current for the synchronous motors. The use of four motors allows for an intelligently controlled, permanent all-wheel drive system that maximizes traction, handling and safety.
There are two separate cooling systems — one for the electric motors and the power electronics and one for the battery. An electric heating element helps get the battery up to operating temperature when the weather is cold and on the other end of the scale, battery cooling can be boosted by the air conditioning system on hot days.
Extending front splitter
In addition to the in-your-face paint job, the SLS E-CELL features a wider radiator grille with transverse slats instead of a diamond-pattern, full LED headlamps and an extending front splitter that drops down seven centimeters at speeds above 120 km/h. The air outlet openings on the bonnet and the vehicle sides have also been tweaked and with no exhaust, the rear diffuser has been designed on a steeper angle to increase downforce.
Interior design elements
Inside the E-CELL, a redesigned instrument cluster displays speed, battery charge and estimated range and a 25 cm touch-screen on the center console gives access to infotainment and climate systems as well as information on the flow of power from the four electric motors. As well as push button start, buttons replace the gear shift for selecting the three drive modes - Drive, Park and Reverse.
"The gullwing offers the prospect of a possible small series production run and at the same time reflects the innovative strength and development competence of the AMG performance brand," says Ola Källenius, chairman of the board of Mercedes-AMG GmbH. "We take social responsibility very seriously and with the SLS AMG E-CELL we are demonstrating a further milestone in our 'AMG Performance 2015' strategy. It is our goal to continually reduce the fuel consumption and emissions of new models in the coming years, while at the same time enhancing the core brand value of performance."
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