From the curb, both Rolls-Royce Phantom limousines look nearly identical. And they feel similar when you’re driving them down the road. But the technology underneath their massive hoods is strikingly different.

The sky-blue Phantom that Rolls-Royce invited journalists to test drive in downtown Los Angeles recently is a one-off called the 102EX. Instead of having the usual 6.75-liter V12 in the engine bay, as its navy blue twin does, it has 96 battery cells bundled into five modules. They power two electric motors located where the fuel tank normally is, between the rear seat and the trunk.

Driving a few city blocks was enough to discern that Rolls-Royce can bring the same class, luxury, and driving experience to electric vehicles as it does to conventionally powered ones.

The interior is retro, with classic dials, glossy wood, smooth leather, and plush, uninterrupted, sofa-like seating in the rear. The 102EX has a special “aluminised foil weave” trim instead of wood, and thick brown saddle leather on the floor.

The steering wheel is large, with a thin rim. Grasp it and you immediately feel more civilized. The effect is almost relaxing. Images of open-top motor coaches ferrying aristocrats and barons a century ago flash through the mind.

The 102EX feels remarkably similar to its gas-powered cousin, thanks to the two powerful electric motors. They provided so much torque that it was hard to tell any difference in pick-up and throttle response between the two cars. The regular Phantom is already so smooth and quiet that the silence and subdued character of the electric drivetrain felt normal, which often isn’t the case with hybrid or electric versions of other cars.

The 102EX can drive about 120 miles on a single charge. The battery composition is lithium-nickel-cobalt-manganese-oxide, a variation of lithium-ion chemistry that Rolls-Royce says has high energy and power density. Overall capacity is 71 kilowatt-hours.

A three-prong charging outlet in the rear passenger-side roof pillar sits beneath a piece of glass that conveniently slides out of the way. When plugged into a standard 120-volt outlet, it takes 20 hours to charge the batteries completely. It takes eight hours using 220 volts. Rolls-Royce projects that the battery pack would last more than three years with daily use.

The Phantom 102EX is also capable of recharging without any physical connection, through what is called induction charging. This requires a transfer pad on the ground that delivers current from a power source. An induction pad under the car receives the current via magnetically coupled power frequencies. The system is 90 percent efficient and is one solution Rolls-Royce is exploring to help alleviate concerns over charging away from home.

There are no plans to produce the 102EX. It’s purely an experimental vehicle designed to test future technology and the reactions of Rolls-Royce owners. The company is processing data on how the technology holds up and what people think of an electric-powered Rolls. A report with the findings is scheduled to be published before the end of the first quarter.

Rolls-Royce spokesman Oleg Satanovsky says the Phantom 102EX covered 4,000 miles on more than 500 test drives in 30 locations across 12 countries. Once the car returned to company headquarters in Goodwood, England, engineers disassembled it to check for wear on electric drivetrain components.

“Some of the findings from a technical side have been data about the effects of heat and humidity on the 102EX’s battery and management systems,” Satanovsky says. “The 96 cells will continue to operate at temperatures as high as 122 degrees Fahrenheit, and in relative humidity as low as 30 percent. The battery management system, which maintains the safety and optimal operation of the individual cells, does inhibit recharging at extreme temperatures, requiring a cooling off period for the cells after a drive before recharge can begin.”

In terms of customer feedback, the lack of charging stations is a key concern, but the 102EX met expectations regarding how a Phantom should drive, with customers citing its quiet, smooth power delivery.

“The range of 120 miles was acceptable to some, but too short for others,” Satanovsky says. “Everything depended on where the people lived and how they used their Phantoms. Someone with a daily commute found the range more than acceptable. But others who use their Phantoms for weekend tours of several hundred miles expressed concerns with finding reliable recharging.”