A battery electric vehicle uses an onboard battery for delivery of electricity. Electric vehicles use electric motors rather than reciprocating engines to deliver mechanical power to their wheels. When the battery in an electric vehicle runs out of charge, it must be either recharged or replaced with a fresh battery. Battery electric vehicles are becoming more popular due to increasing oil costs and environment concerns about vehicle emissions.
An electric motor converts an electrical current into mechanical motion by using magnets. Electrical currents are moving streams of charged particles, which create their own magnetic field. Likewise, magnets on the other side of an electric motor produce a field of their own. When these fields interact, they result in a torque, or twisting force, between the two halves of the motor. Thus, the stronger the electrical current, the more mechanical power the engine will produce.
This mechanical rotation can be distributed to an automobile’s wheels in the same way as conventional cars. A car, truck or bus powered by an electric motor has the same function as if it was powered by gasoline or diesel fuel. Apart from the lack of an exhaust system, electric vehicles often look identical to conventional vehicles.
For an electric motor to work, it needs an immediate source of electricity. The onboard battery differentiates the battery electric vehicle from other types of electric vehicles. These types of batteries are expensive, but will likely become more economical when more electric vehicles are used. Other types of electric vehicles, such as buses and trains, maintain electrical contact with power lines along the road or track. This eliminates the need for a battery, but requires specialized infrastructure along the paths of travel.
Though batteries can be used to temporarily store electrical energy onboard an electric vehicle, they must be periodically recharged with electricity. This typically comes from stationary power plants, such as coal, oil or nuclear energy. An owner of a battery electric vehicle can charge his battery by plugging it into the electricity grid.
Increases in oil prices have been correlated with increases in demand for fuel-efficient automobiles. A battery electric vehicle uses standard electricity, which is much cheaper per mile than the equivalent amount of gasoline. The reduction of exhaust emissions is also an advantage of electric vehicles. Though some emissions may result from the original power plant, this is less than in an internal combustion engine.