General Motors has announced plans to sell a serial hybrid car, with a prototype available early next year.

A serial hybrid means that the car has two engines, but only one engine is connected directly to the drive train, hence it is a “serial” hybrid.

It is less complex than conventional hybrid cars, because only the electric motor, with its huge range of usable RPM, is connected to the drivetrain.

Another huge advantage is that serial hybrid cars have their second motor, a small, ultra-low-emission gas or diesel engine, connected to a generator to recharge the battery pack while the car is being driven. By doing this, a cheaper and more reliable battery pack can be used, and there is no need for a complex heat management system.