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Exterior Design

102EX bears the famous hallmarks of the Rolls-Royce Phantom on which it is based, such as hand craftsmanship, fine detailing and iconic design cues like the pantheon grille and the Spirit of Ecstasy which celebrates its centenary in 2011. However, at the core of its design is the essence of an experimental vehicle, establishing this car's status as a test bed, while subtly alluding to its electric power plant.

The design creates a different aesthetic, experimenting with interior space and materials, as well as trims and illumination. These are framed around functional considerations for a battery electric Rolls-Royce - how the car is likely to be used and the changes that the technology brings in terms of interior space and exterior detailing. Naturally, these changes are executed in a way that affirms the car's credentials as a Rolls-Royce.

Interior Design

Atlantic chrome-finished dashboard dials echo the exterior color, providing a sense of interior-exterior balance and their analogue displays maintain the timeless architecture that every Phantom interior commands.

Other changes hint at further evolutionary designs applied to the car. For example, some dials have been subtly modified to provide information needed by the driver of an electric vehicle. The fuel gauge in particular has been replaced by an elegant battery charge indicator.

One of the most pleasing features of every Rolls-Royce Phantom interior is the power reserve dial located beside the speedometer. This reveals how much of the V12 engine's power remains at a driver's disposal. Phantom EE takes this concept a step further.

It features a regeneration symbol which takes the dial beyond the normal 100% line of standard Phantom. Depending on the momentum gathered, it conveys the degree of re-charge taking place as the vehicle is in motion.

Interior wood veneers present Phantom owners with unique grains, patterns and detail adding weight to the fact that every model leaving Goodwood is as unique as the finger print of its owner. Phantom EE takes this concept a step further.

Its leather interior is derived from a natural vegetable tanning process christened Corinova. This gives life to the car, adding definition to the seats, floor and arm rests.

The Drivetrain

The latest in this line of experimental projects began with a Rolls-Royce Phantom, a strikingly modern and immaculately proportioned car in which high technology and hand-craftsmanship combine to produce something extraordinary.

Phantom EE features the car's ground-breaking aluminum spaceframe, so important to dynamic prowess, as well as the sense of calm and tranquillity enjoyed by occupants. However, the naturally aspirated 6.75-liter V12 petrol engine and 6-speed gearbox have been replaced by a lithium ion battery pack and two electric motors mounted on the rear sub-frame. These motors are connected to a single speed transmission with integrated differential.

Each motor is power rated to 194 hp, giving Phantom EE a maximum power output of 389 hp and torque of 590 lb-ft (800 Nm) available over a wide band. This compares with 453 hp for standard Phantom with maximum torque of 531 lb-ft (720 Nm), delivered at 3,500 rpm.

The Nickel Cobalt Manganese battery chemistry holds around 230Wh/kg, a high energy density which is important in achieving an acceptable range between re-charges. Pre-launch tests suggests Phantom EE should run to a range of up to 124 miles (200 km). Delivered on an effortless wave of torque, 0-60 mph will be achieved in under eight seconds (5.7 seconds in standard Phantom), with top speed limited to 100 mph (160 km/h).

This is the first application of the technology in a GKL++ segment (super luxury vehicles priced at more than $300,000) and the battery pack is thought to be the largest ever fitted to a road car.

Battery Re-Charging

Re-charging is undertaken with a plug and five-pin socket which takes the place of the normal fuel filling mechanism for Phantom. The standard fuel filler cap has been replaced by a design featuring a clear window, displaying the RR logo and 102EX motif. The window frames rear-mounted, tricolor LEDs which present the car's charging status.

On start up, the socket is bathed in blue light. This begins to flash as charging commences. When completely charged, the display turns green, then flashing green as the solenoid is disengaged. A potential fault in the system is indicated by either constant or flashing red light.

Charging can be halted via a switch located adjacent to the plug. The process can also be operated inside the vehicle using controls accessed beneath the center console, for example when induction charging is taking place.

Battery Pack

Phantom EE is thought to have the largest passenger car battery in the world. Peak current is 850A, delivered at 338V DC. Overall capacity is 71kWh.

The pack is comprised of large-format NCM pouch cells. NCM (Lithium-Nickel-Cobalt-Manganese-Oxide) is a variant of lithium-ion chemistry that has particularly high energy and power densities.

The Phantom EE battery pack houses five modules of cells, a 38-cell module, a 36-cell module, and three smaller ones of ten, eight and four arranged in various orientations within an irregular shaped unit. This resembles the overall shape of the original engine and gearbox.

Each of the 96 cells was individually tested before assembly into modules to determine their characteristics and capacity. Sub-assemblies were further tested under load to verify that the power connections between each cell perform to specification.

The electronic sensing units for each group of cells were tested and calibrated prior to assembly and put through a rigorous temperature cycling regime designed to provoke failure of weak components. The main electronic box, which contains the switching and control gear, was tested in isolation from the other components to verify correct operation.

Three separate charger units (3kW each) are fitted to the battery, which allow both single-phase (20 hours) or three-phase charging (8 hours); for a passenger car this is unique. A fourth induction charger is also fitted to enable wireless charging, a technology being trialed in Phantom EE.

The battery pack would be expected to last over three years were it to be used every day. Part of the program however will be to test this assumption in a real world environment and deliver a more robust answer to the question of battery lifespan.

Induction Charging

Concerns about lack of available re-charging infrastructure in towns and cities are well documented and critics of electric motoring point to the additional inconvenience of trailing cables connected between power source and vehicles.

To present Rolls-Royce owners with a vision of a potential solution to these problems, Phantom EE is testing a technology called induction charging. This allows re-charging to take place without any physical connection, delivering greater convenience for owners and hinting at the potential for a network of remote charging facilities.

There are two main elements to induction charging; a transfer pad on the ground that delivers power from a mains source and an induction pad mounted under the car, beneath Phantom EE's battery pack. Power frequencies are magnetically coupled across these power transfer pads.

The system is around 90 percent efficient when measured from mains supply to battery and it is tolerant to parking misalignment. For example, it is not essential to align the transmitter and Phantom receiver pads exactly for charging to take place. While pads are capable of transmitting power over gaps of up to 400mm, for Phantom EE the separation is in the region of 150mm.

Rolls-Royce 102EX Phantom Experimental Electric Concept: Photo Gallery, Review (1/2) and Specifications