The Mighty MINI "Wow" Demo

Green Car Congress
August 29, 2006
Michael Millikin

British electric-motor developer PML Flightlink unveiled an in-wheel, plug-in series hybrid conversion of a MINI--the MINI QED--at the British Motor Show in July.

The impressive MINI QED supports an all-electric range of 200-250 miles and has a total range of about 932 miles (1,500 km). The car accelerates from 0-62 mph in less than 5 seconds.

The car will not be sold. Its purpose is to serve as a testbed and demonstrator for technologies that PML hopes to commercialize, such as the in-wheel motors. The QED provides a terrific proof point of what is now feasible technically, if not economically.

The QED is a series hybrid; all traction is electric, powered by a large battery pack that is periodically recharged by a small engine functioning as an electric generator (genset).

This initial version of the car uses four 750 Nm brushless permanent motors in its wheels, a 21 kWh lithium-polymer battery pack from an unnamed Asian provider, and a 250cc two-cylinder, four-stroke engine as the genset.

PML also incorporated a 350V, 11 Farad ultracapacitor to discharge the high current for acceleration and to accept the regen power back from braking. This design protects the batteries from high current spikes.

PML is working on the engine component and may change it in the near future.

The car has three operating modes:

· Eco, in which the engine will not start unless directed by the driver;
· Normal, is which the genset starts when the battery drops to a 50 percent state of charge (SOC); and
· Sport, in which an enhanced performance profile is laid onto the Normal mode.

Anti-skid and traction control capabilities are built into each wheel.

On paper, the MINI QED sounds like an absolute delight. The major barrier to actually commercializing it now would be, of course, the cost of the battery. That battery cost, however, would be much lower than the current cost of a hydrogen fuel cell.

The most likely car of the future will be electric: electric motors for traction, electric subsystems for all other functions. The big question is whether the electricity needed to power the vehicle will be stored in an advanced battery, or carried in the form of hydrogen, that then flows through a fuel cell to generate the electric current.

Speaking at last week's Diesel Engine-Efficiency and Emissions Research (DEER) 2006 conference held by the Department of Energy, John Amdall, the director of engine research and development at Caterpillar said, "Here’s where we put hydrogen. Hydrogen is an energy storage medium, in direct competition with things like batteries. We see a technology race emerging between hydrogen and batteries as we move to the future."

The Mini QED is a very strong demonstration for the prospects of batteries in that race.