it may be considered a motor vehicle. But I don't think it is.
It is and there is an example. The Chevrolet Volt, also known as the Vauxhall Ampera is General Motor's electric car. It's range is around 80 miles, but when the battery runs down there is an auxilliary 2 litre engine that cuts in to both charge the battery and supply the car's electric motor.
Logically it's just an electric car since only the electric motor drives it, but the authorities say no, and here's how. Electric cars are automatically exempt the London Congestion Charge, but the Volt/Ampera are not, they are included with other ic engined cars for consideration under the level of emissions. Because they are below the 75 g/km emission level they do get exemption, but only as a low emission ic car, not as an electric car.
It follows that using a petrol motor while in motion to charge a battery that can be used to drive an e-bike makes it a motor vehicle for this reason alone.
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