Hybrid cars get their power from two sources: a conventional gasoline engine and an electric motor. The gas engine is usually small and efficient, but otherwise works like any other. The electric motor is fed by an on-board battery pack and assists with powering the car. Many hybrids can run on electricity alone at low speeds or when power demands are slight. The result of this dual-source approach is a car that uses significantly less fuel than gas-only vehicles of similar size.
The Electric Drive System
Every car generates electricity when running. A hybrid system harvests this energy, which would otherwise be wasted, and stores it in the battery pack. As you drive, the battery is constantly charging, which in turns allow it to keep the electric motor going. It's available at all times to assist the gas engine and even take over powering the car when possible. The system continuously responds with the appropriate mix of gas and electric power for the conditions.
A hybrid gives you the benefit of electric power without its major drawback, limited range. Electric-only vehicles can only go so far on a full charge, typically 80 to 120 miles. After that, you have to recharge the battery on an outlet, which can take a few hours. With a hybrid, you get the same driving range as any other car. So long as there's gas in the tank, you're good to go. Of course, the fact that you're using gas at all is a compromise, but it's one that even the most eco-conscious buyers can happily live with.
Hybrids also offer regenerative braking, which means the energy produced during braking is captured and fed to the battery pack. This action increases the charge available to the electric motor, which results in even less fuel consumption. It's a major reason why hybrids are able to achieve such excellent efficiency in city driving.