Seven Defender EV Prototypes To Be Unveiled In Geneva
The good old go-anywhere, do anything Defender is giving electric propulsion a try.
Land Rover will be unveiling seven Defenders converted to run on electric power at the 2013 Geneva Motor Show.
The seven research vehicles deliver zero emissions while retaining their tough, range-traversing capability.
“Investing in innovation has always been the lifeblood of our business and our engineering teams are working hard to develop innovative new technology to provide sustainable motoring solutions,” said John Edwards, Land Rover Global Brand director.
The standard diesel engine and gearbox in the 110 Defenders have been replaced by a 70 kilowatt (94 horsepower) electric motor combined to a 300 volt lithium-ion battery with a capacity of 27 kilowatt-hour. Land Rover said the combination is good for a range of more than 50 miles.
In typical, low speed off-road use it can last for up to eight hours before recharging. The battery can be fully charged by a 7 kilowatt fast charger in four hours, or a portable 3 kilowatt charger in 10 hours.
These electric vehicles (EVs) retain the Defender’s legendary four-wheel drive system and differential lock. Because the electric motor delivers maximum torque from the moment it starts, there’s no need for gear shifting and the transmission is comprised of a single speed, 2.7:1 reduction gearbox combined to the existing Defender four-wheel drive system.
A modified version of Land Rover’s Terrain Response System has also been incorporated.
These vehicles were developed by Land Rover’s Advanced Engineering Team following successful trials of the Defender-based Leopard 1 electric vehicle.
Land Rover said the vehicles’ capability has been tested in extreme and environmentally sensitive conditions, demonstrating capabilities not shared by conventional road-going EVs. Trials included pulling a 12-tonne ‘road train’ up a 13 percent gradient and wading to a depth of 800mm (32 inches).
The battery weighs 410 kilograms (904 pounds) and is mounted in the front of the Defender in place of the diesel engine. The conversion adds 100 kilograms (220 pounds) to the Defender 110.
All the major components in the electric powertrain – including the battery, inverter and motor – are air-cooled rather than liquid cooled. Land Rover said it did so to save weight and complexity while adding robustness.
Regenerative braking has been optimized to such an extent that using Hill Descent Control, the motor can generate 30 kilowatt of electricity. According to Land Rover, because the battery technology can be charged very quickly at a rate of up to twice its capacity of 54 kilowatt without reducing battery life, almost all of the regenerated energy can be recovered and stored. In theory, up to 80 percent of the kinetic energy in the vehicle can be recovered this way.
“This project is acting as a rolling laboratory for Land Rover to assess electric vehicles, even in the most arduous all-terrain conditions. It gives us a chance to evolve and test some of the technologies that may one day be introduced into future Land Rover models,” said Antony Harper, Jaguar Land Rover Head of Research.
Although there are no plans for the all-terrain electric Defender to enter production, the seven EVs will go into service in real world trials later this year.