Geneva Watch: Rolls-Royce 102EX – A Very British Success Story

Geneva Watch: Rolls-Royce 102EX - A Very British Success Story

Geneva has certainly been rocking these last few days, as manufacturers struggle to get their exhibition entries ready for the critical gaze of the public eye. As you would imagine, Geneva is the largest automotive exhibition of the year and it is essential that automotive brands in development, in terms of both image and technology, have something that stands out at the show.

Manufacturers such as Alfa Romeo, Lamborghini, Gumpert, Lancia and De Tomaso all have much riding on their entries of the 2011 Geneva Motorshow being popular attractions. The show will give these manufacturers an indication of whether their forthcoming models are on the right path in terms of desirability, design and technology, and will help push their brand of design into the future.

One manufacturer that arguably has their core market already boxed, bundled and guarded under lock and key, would be Rolls-Royce. RR arguably enjoy the most inelastic of demand curves for their products – If you are a customer, it makes no difference how much the car costs – so long as it has all the trimmings one would expect.

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One trimming you may not expect in your RR, however, is that featured by the ‘102EX Concept’, which is under the bonnet.

In a glorious twist of style, and possibly showing some humour and enthusiasm for the technology, is a perfectly formed battery Cell, quoted as being the largest ever used in a road car.

Yes, you guessed, it, the car that began life as a regular Phantom is now anything but as it features a massive, new, 96-cell, 338 Volt battery perfectly shaped to resemble the original 6.75 Litre engine and transmission.

The Axeon power pack

Whilst Rolls-Royce claim that this car will not go into production, they also seem quite proud of what they have achieved.

The car is capable of reaching 0-60 in under 8 seconds, and is wirelessly chargeable via an electrical mat that begins charging the car as soon as you drive and park on it.

You can also charge the car through a mains adapter where the fuel filler resides on the regular car.

Other features include the opaque ‘Spirit of Ecstacy’ lit up blue, with other blue themes running inside the car. All other luxuries you would expect to find in a Phantom are duly present and correct.

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Steve DaviesSteve Davies
Wednesday 02 March 2011, 15:32 GMT

Lotus Engineering and the 102EX’s electric drivetrain

You might be surprised when I tell you that Lotus Engineering, a company with over 20 years of EV and HEV experience, has been responsible for all aspects of the electric drivetrain integration for 102EX, the Rolls-Royce Phantom Experimental Electric. This includes the largest battery pack fitted to a road car, together with an innovative 7 kW induction charging system.

The Phantom Experimental Electric has two electric motors to replace the 6.75 litre V12 engine. These electric motors each produce 145 kW of power to provide a total 290 kW and torque of 800 Nm giving a 0-62 mph time of under eight seconds and a top speed limited to 100 mph.

In the conversion of a Phantom into an electric vehicle a study was conducted to ensure that the optimum layout of the electric drivetrain and ancillaries was achieved with no intrusion into passenger compartment. Following an iterative design study the 71 kWh, 640 kg lithium ion battery pack was placed under the bonnet where the engine had been.

The Rolls-Royce Phantom is a complex vehicle with many advanced electrical systems, so the integration of the electric drivetrain and ancillaries with the existing vehicle control unit provided the greatest challenge for the Lotus Engineering team.

To compound this the Phantom Experimental Electric features the additional complexity of a 3 mode charging system (single phase, three phase and the inductive power transfer) together with a two level driver selectable regenerative braking system.

The two motors, gearbox and inverters were located behind the rear seats in the original fuel tank bay, with power cables running longitudinally between the converters and the battery. This has enabled the Phantom Experimental Electric to retain its 50:50 weight distribution and characteristic Rolls-Royce driving experience.

There’s world class talent at Lotus Engineering, so it’s great to see them involved in such an innovative project. Other sporting names you might recognise who are world leaders in electric vehicle (EV) technology include McLaren Electronic Systems and Williams Hybrid Power, who provide regenerative braking systems (KERS) to numerous industries outside Formula One.


A British Success Story

Okay setting aside the fact that Rolls-Royce Motor Cars are owned by German company BMW, and Lotus Engineering by Malaysian company Proton, they’re based in the UK and they’re mostly staffed by some of our best British engineers and craftsmen (male and female).

Lotus Engineering, Axeon & Xtrac

The same is true of Dundee based Axeon who developed the 102EX’s lithium-ion power pack, and renowned motorsport transmission specialists Xtrac, who designed a unique rear wheel drive transmission system for the 102EX capable of harnessing the prodigious amounts of torque delivered by twin electric motors and doing so in a quiet and refined manner befitting a Rolls-Royce.

The Axeon power pack for the car uses 96 lithium ion pouch cells which, thanks to some complex package engineering completed by Axeon’s technical team at its Dundee, Scotland headquarters, fit into the space normally occupied by the car’s conventional engine and transmission.

The power plant will now undergo extensive trials within the 102EX as it travels around the world, being appraised by customers and local media and put through its paces in variety of climates.

The Axeon battery system is believed to be the biggest passenger car battery built in the world, both in terms of capacity and power, with 71kWh overall capacity and 388V DC nominal power. The peak current that can be delivered is 850A (330Kw) which is equivalent to around 450 bhp.

Picture Gallery

  • Here is Similar Story

    Rolls-Royce’s electrically-propelled Phantom, unveiled at Geneva today, is a rolling testbed rather than a production car preview.

    The company is keen to investigate the acceptability of alternative propulsion systems among its customers, as well as understanding the real-world practicality of this prototype.