The PHEV is based on Honda's "Inspire" sedan. The company combined an in-line four-cylinder Atkinson cycle engine with a displacement of 2.0L, two motors and a lithium-ion (Li-ion) rechargeable battery. One of the motors has a maximum output of 120kW and is used to drive the vehicle and regenerate energy. The other is used as a generator that can generate about 100kW of electricity.

The most distinctive feature of the PHEV is its two-motor system, which is different from the one equipped in Toyota Motor Corp's PHEV and can independently operate the engine and the motors. As a result, it becomes possible to drive the vehicle (1) as an EV only by electricity, (2) as a hybrid vehicle by using the engine and the motors and (3) as a gasoline vehicle by using only the engine.

Fig 2: The inside of the PHEV's hood. A motor and a generator are located next to the 2.0L engine.

Also, it is possible to drive the vehicle as an EV while using the engine and the generator to generate electricity and storing it in the Li-ion rechargeable battery, Honda said.

Though the company did not disclose the details, it placed the driving motor and the generator next to the engine so that the engine and the motor can be disconnected by using a clutch. In the case of Toyota's hybrid system, its engine, motor and generator are connected by planetary gears and cannot be disconnected, making it impossible to drive only the engine.

As for the Li-ion rechargeable battery, a battery pack with a capacity of 6kWh is mounted in the trunk. And the PHEV can drive about 25km only by electricity. The charging time is less than four hours when charged at a voltage of 100V and less than 1.5 hours when charged at a voltage of 200V.

The cell of the battery is manufactured by Blue Energy Co Ltd, a joint venture of Honda and GS Yuasa Corp. The cell is made by using different materials from those used for the battery of the Civic Hybrid, which will be released in 2011.