A hybrid-electric vehicle, or HEV, combines an electrical energy storage system with an occupied means of generating electrical energy, usually through the consumption of some type of fuel. Each type of HEV has its own operating quality and chosen design practices, as well as advantages and disadvantages.

The development of interior ignition engine vehicles, especially in automobiles, is one of the supreme achievements of modern technology as a new rising energy saving and environment -friendly vehicle, that's why the hybrid-electric vehicles were created to give convenience to every human.

In the process of creating the hybrid electric car, the most important is the energy saving and the environmental protection. Wherein nowadays this are the common problems faced by the society.

Having the hybrid-electric car evolved from the electric car. However, the main disadvantage of the electric car is that it is mainly dependent on the batteries. Therefore, has limited range.

First of all, the hybrid electric car was supposed to be an electric vehicle with batteries for power storage and is also equipped with an on-board heat engine-powered generator. This means that this type of hybrid has an extended range.

The heat engine power and the battery power are specifically intended as an important scheme that constantly modulates the excess between the heat engine and the battery power systems. This will also depend on the driving schedule.

Since the beginning of the use of automobiles, electric cars have been already recognized and conceptualized. Even though the electric power train is better in various aspects, as an energy source, the battery was unequal to the superior-energy content, easiness in terms of the handling, and inexpensive and profuse supplies of motor fuel.

Now, it has almost been a century since the electric car has been popularly discussed, but recent developments in the HEV technology and the growing concerns for the environment has revived the drive for an HEV and this has become a realization today.

We can consider the personal means of transportation as a very important bond in the economic chain of today's modern societies and that a private vehicle appears to be the popular choice.

Electric vehicles are more energy efficient than the contemporary vehicles wherein the electric vehicles operates at approximately 46 percent of effectiveness, while a contemporary vehicle operates at about 18 percent only.

There are studies that generally concludes that electric cars with batteries are approximately 10 to 30 percent more efficient with energy than the usual gasoline cars, depending on the exact assumptions of the vehicles energy usage and energy chain efficiency.

Certainly, the comparisons of the electric vehicles and the conventional vehicles are comparisons between an extremely developed power system that is nearly in the end of its research and development, and the innovative power system in the beginning stages of the development wherein important development can be expected as the new technology evolves.

Furthermore, the advantages of electric powered modes of transportation extends beyond the true outlook of economizing energy. Electric generation plants can use substitute fuels that are not adaptable to portable power systems.

Electric vehicles are the definitive alternative fuel vehicles because their power is taken from the source fuels utilized to produce electricity. Aside from that, the flexibility of the fuel alone can offer important useful and economic advantages especially in relation to a variety of energy resources.

The electric car is truly a promising technology that could transform one's means of transportation into a far more environmentally type of commodity. Through this innovation emission controls become more important, effective and economically beneficial.