CAR tech: building the world's fastest EV

By Jesse Crosse

Motor Industry

07 October 2013 09:00

What if you could toss all the qualms about electric cars out the window and build one that doesn’t care one iota about range nor looking like a conservative marshmallow designed by styling clinics? The Drayson is exactly that: a Lola-chassised EV that’s been built with no intention of beating the London Congestion Charge, but instead with the sole aim of swallowing Tarmac as quickly as possible. Its top speed? A handy 204.185mph – the new World Land Speed Record for an electric vehicle, set by owner Paul Drayson. So what makes this electric supercar tick?

The Lola-Drayson B12/69EV, the official name given to this green monster, has not one but four aluminium, asynchronous, three-phase, permanent magnet electric motors. Each ‘pancake format’ motor, weighs 25kg and started out with 121bhp. Drayson’s coy on exactly what it’s done to develop them, but they now make 268bhp – each! The oil-cooled motors are mounted forward of the rear axle in pairs, each pair driving a rear wheel individually through a single speed reduction gear. Like the Audi R8 E-Tron and Mercedes SLS AMG E-Cell, the Drayson’s torque vectoring sends more or less torque to each wheel to improve turn-in and cornering balance. In ‘race qualifying’ trim, the motors develop 850bhp, where they deliver a Bugatti Veyron-busting 0-150mph time of 8.5 seconds.

The lithium-ion batteries pushing this 200mph EV aren’t the same as in your smartphone: phosphate was chosen as it’s more stable than other lithium-ion chemistry and safer as a result, plus it has a high energy density (stores a lot of energy for its size and weight). The 800-volt battery contains 2660 individual cells in two modules and weighs 200kg. Its capacity is 24kWh (the same as a Nissan Leaf, funnily enough) but because of its modularity, can be altered to suit the job at hand, for better range, power and/or weight.

It’s not just fast on the road: the Drayson takes a mere 40 minutes to charge from flat, using state-of-the-art conductive charging (something in the works at Audi, Nissan and other manufacturers). Plug in a Nissan Leaf when it’s flat, and you’ll wait eight hours before charging’s complete.

You’ve heard of regenerative braking, but the B12/69EV goes further, using its suspension movement to generate electricity. It only makes a small amount, but it’s enough to operate its own control systems. There’s great scope for this on the road, where there’s much more suspension movement.

By Jesse Crosse