Land Rover is all set to become the latest carmaker to offer zero-emission vehicles with seven new electric models of its Defender at the upcoming 2013 Geneva motor show.
The standard diesel engine and gearbox in the 110 Defenders have been replaced by a 70kW (94bhp), 33.65kgm electric motor twinned with a 300-volt, lithium-ion battery with a capacity of 27kWh, giving a range of over 80km. In typical, low speed off-road use, it can last for up to eight hours. The battery can be fully charged by a 7kW fast charger in four hours, or a portable 3kW charger in 10 hours.
The electric vehicles (EVs) retain the Defender’s 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 comprises a single-speed, 2.7:1 reduction gearbox combined with the existing Defender four-wheel-drive system. A modified version of Land Rover’s Terrain Response System has also been incorporated.
In keeping with Land Rover’s ‘Tread Lightly’ philosophy, the smooth, low-speed capability of the electric drivetrain makes the electric Defenders especially well suited to climbing obstacles without damaging the ground unnecessarily.
The battery weighs 410kg and is mounted in the front of the Defender in place of the diesel engine. Kerb weight is 100kg more than a basic Defender 110 and ranges from 2055kg to 2162kg depending whether the body style is a pick-up, hard top or station wagon. All the major components in the electric powertrain – including the battery, inverter and motor – are air-cooled rather than liquid cooled, saving a considerable amount of weight and complexity and adding robustness. Regenerative braking has been optimised to such an extent that using Hill Descent Control, the motor can generate 30kW of electricity. Because the battery technology can be charged very quickly at a rate of up to twice its capacity of 54kW without reducing battery life, almost all of the regenerated energy can be recovered and stored. Up to 80 percent of the kinetic energy in the vehicle can be recovered in this way, depending on conditions.
Land Rover, however, has no plans for the all-terrain electric Defender to enter series production yet.