A hybrid car is a vehicle that is powered by two fuel sources. In most cases the two fuels are gasoline and electricity. Unlike an electric powered vehicle, a hybrid vehicle’s electric batteries are charged by driving the vehicle, so there is no need to plug the car into an electric power source. With electric hybrids, there are two typical types of hybrid cars; these are parallel and series hybrid engines. There is a new technology emerging as a third type of hybrid; it is called a hydraulic hybrid.
With a parallel hybrid car, both the gasoline powered engine and the electric powered engine can power the transmission. When driving at low speeds, the electric motor turns the transmission. When the vehicle reaches a speed of approximately 30 miles per hour and needs more power than the electric motor can deliver the gasoline engine starts and adds the additional power needed. The batteries are charged when the engine is slowing down or during braking.
A series hybrid vehicle transmission receives its power from the electric engine. The gasoline engine part of the configuration is used to either power the electric motor and any additional power will be used to charge the batteries. With this type of hybrid, the gasoline engine is only used to create electricity for the electric powered vehicle.
With the hydraulic hybrid there is a pump that is powered by the engine. When the vehicle is slowing down, the pump is used to pressurize an accumulator tank. When the vehicle needs power, this pressurized fluid is sent through a turbine which turns the transmission. The fluid then enters a low pressure tank used as a reservoir to be later pumped back into the accumulator to develop more pressure.
For more general information on Hybrid cars, check out the articles below.