How Do Electric Cars Work?

No longer the stuff of science fiction, electric cars are becoming a reality. How do electric cars work? To put it simply, electric cars run on electric motors rather than gasoline or ethanol powered motors.

When you lift the hood of a standard gasoline or fuel-powered automobile, you’ll see all sorts of hoses, making a typical fuel-driven engine appear like a large complicated piece of plumbing. In place of a standard engine’s coolant lines, fuel pumps, intake manifold, and exhaust system, an electric car will have a controller, an electric motor, and a large rechargeable battery. Think of an electric motor as a giant piece of electric work.

The one thing most people notice first about an electric car is that it runs nearly silently. At startup, most electric cars interior noises (beeps signalling the driver to put on their seatbelt, the radio, etc) are much louder than any noise coming from the engine. Think of this ‘silent run” as the most obvious evidence of these electric cars environmental friendliness — there’s no exhaust, as these cars are usually powered by “fuel cells”, which leave behind only heat and water, whereas gasoline powered cars release more pollutants than is possible to list here.

How Electric Vehicles Work

Getting back to how electric electric vehicles actually “work” — the most basic definition would be that an electric car draws power from an onboard source of electricity.

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An electric car stores its energy on board the vehicle — typically this is done in batteries, but the electric energy could easily be stored alternatively with capacitors or flywheel storage devices. Another popular possibility — electric cars may generate energy using a generator or onboard fuel cell. A fuel cell is a specialized type of battery that mixes hydrogen with oxygen resulting in a chemical reaction that produces electricity and water vapor. Unlike an electric cell or battery, a fuel cell does not run down or require recharging — it operates as long as the fuel source and some type of fuel “oxidizer” are supplied continuously from a source outside the cell. Most versions of electric cars use a combination of these energy sources. “Pure” electric cars, as we understand them, run only on batteries, and require a charger to replenish the battery’s power from an electrical outlet. That’s right — you can plug in your car like you would plug in a hairdryer.

Most electric cars use “lead-acid batteries”, but all new types of batteries are becoming more common. These new types of batters include zinc-chlorine, nickel metal hydride, and sodium-sulfur. As battery technology improves, so does the electric car itself. The conventional HEV uses a nickel metal hydride battery, while some automakers are currently considering using lithium-ion batteries. General Motors in particular has made big noise about using lithium-ion batteries in their hybrid electric vehicle known as the Volt. The motor of an electric car controls the battery’s electrical energy by converting it into what is known as “kinetic” (or “movement”) energy. The driver of the electric car simply switches on the power, selects “Forward” or “Reverse” with another switch, and steps on the accelerator pedal. Driving an electric car is arguably easier than driving a standard fuel-driven vehicle.

Hybrid Electric Vehicles

In contrast, the hybrid electric vehicle (or HEV) uses both an electric motor and a gasoline or diesel engine to extend the car’s range, boost the car’s gas mileage, and provide an additional source of power. A conventional HEV, like the much hyped Toyota Prius, uses battery power up to a certain speed (around 23 MPH) and the gasoline engine kicks in for higher speeds. An HEV’s engine system can draw on both power sources if needed. The batteries are automatically recharged by the gasoline engine, which acts as a generator for the battery. In most HEV models, the battery is also recharged by the energy generated from the action of braking.

Another type of HEV, known in the industry as a plug-in hybrid electric vehicle or PHEV, uses an extra battery or series of batteries to further extend the range of the automobile. The PHEV can be plugged into a typical 120-volt electric outlet, like those found in most households, for a recharge, meaning the consumer won’t have to look for special “recharging stations” or pay for additional hardware or installation in their garage.

Regardless of the energy source, an electric car needs something called a “controller”, which is connected to the accelerator pedal. The controller is used to direct the flow of electricity from an energy source to the motor itself.

The idea to run a car on electricity is by no means a new one. The first “electric car” was invented by a Scotsman named Robert Anderson. Powered by non rechargeable battery cells, the car was bulky and slow and never caught on. The first electric car in America was built by a relatively unknown inventor from Iowa in 1891 — the car was a kind of minor success in that it led to an exhibition of electric cars in 1893 in Chicago. In the late 19th century, many taxis in New York City were run exclusively on electricity, even leading to the founding of a major electric car manufacturer, the Pope Manufacturing Company of Connecticut. Even Thomas Edison, the great American inventor, believed that cars of the future would run on electricity, began working on a practical battery system, and between 1899 and 1910 he tried again and again to create a system that would work. Frustrated by his failues, he abandoned the project, and the idea of an “electric car” died with him.

It wasn’t until 1997, when Toyota made a full fledged release of its now hyper popular Prius line in Japan, that electric cars seemed feasible. Of course, the Prius is not technically an ‘electric car’ — it is a hybrid vehicle that runs on gasoline backed up by an electric motor. The success of hybrids like the Prius is an exciting sign, but by no means does it indicate that cars will soon be fully electric. That will take a great amount of research, infrastructure, and consumer confidence.