Mercedes SLS AMG E-Cell (2010): the electric SLS

Following the unveiling of Tesla's updated Roadster 2.5, Mercedes is showing off its iteration of an all-electric sports car: the SLS AMG E-Cell.

While the regular SLS pumps out 563bhp and 479lb ft from its 6.2-litre V8, the SLS E-Cell has four synchronous electric motors, powering all four wheels for a combined output of 392kW (equivalent to 526bhp) and a mammoth 649lb ft of torque.

Crucially, all of that power is accessible from zero revs, allowing the E-Cell to sprint to 62mph in four seconds dead. That's about the same as the petrol version, despite the weight penalty.

Powering the SLS AMG E-Cell is a bank of liquid-cooled lithium-ion batteries, which have been installed in front of the firewall, in the centre tunnel and behind the seats in order to offset the batteries' extra weight.

Bringing the electric car to a halt are massive 402mm energy-recuperating carbon-ceramic brakes.

Externally, the SLS E-Cell has received a few tweaks to differentiate it from the petrol car.

Aside from the radioactive paint job, the car receives energy-saving LED headlights, a wider grille and an automatically extending front splitter, which is deployed above 75mph to increase downforce at higher speeds. Handy for the speed police as well.

Inside the E-Cell the centre console has been redesigned to accommodate instruments specifically for the electric drive system. And Mercedes has installed a huge 25cm touchscreen, replacing almost all the dashboard buttons in the process.

Unlike most electric concepts, Mercedes has promised to have this on sale by 2012. Prices are still to be announced, but expect a heavy premium nudging the SLS nearer £200k for this futuristic electric supercar.

By Mark Passer