You have probably heard about electric cars in the news or read about them on the Internet. The public has continuously albeit slowly shown interest in these modern cars. For one, electric cars generate less air contaminants than gasoline-based cars, making them environment-friendly. Hybrid cars are also considered as electric cars. If you see a car that is powered by fuel cells, then you’re looking at an electric car. These fuel cells get a lot of public attention right now, especially in the news. Instead of a gasoline engine, electric cars have electric motors. A single electric car looks so much like a gasoline powered car on the outside. But in most cases, an electric car is made from the conversion of the regular car to electric. This makes it pretty impossible to tell if a car is electric or not on the outside. Probably the one thing that can help you easily distinguish an electric car is its silent driving nature. If you look under the hood of an electric car and a gasoline car, you will see a number of differences. An electric car is first made by replacing the gasoline engine with an electric motor. The controller obtains power from a variety of rechargeable batteries then distributes power to the electric motor. While a car with gasoline engine has exhaust pipes, intake manifold, fuel lines, and coolant hoses, an electric car only features a series of wiring.
? The Tesla Model S. Source: Wikipedia
Now, let’s start the journey by examining the interior of an electric car. The heart that governs all electric cars includes the combination of the batteries, the motor’s controller, and the electric motor. From the power generated by the batteries, the controller then delivers this power to the car’s motor. A pair of potentiometers or variable resistors is hooked to the accelerator pedal. These potentiometers are responsible for providing a signal to the controller about the level of power that should be delivered. When the car is parked or stopped, the controller delivers zero power and when the driver steps on the accelerator pedal, the controller gives the motor full power. Let’s take the case of a U.S. electric car (patented or not). The controller first takes 300 volts of direct current from the batteries. This power is then converted to a maximum level of 240 volts alternating current to be sent to the motor. This process is done through the use of large transistors rapidly turning the voltage of the batteries on and off in order to produce a sine wave. When the gas pedal is pushed, the pedal’s cable then connects to the potentiometers. The signal coming from the potentiometers indicates the amount of power to be delivered from the controller to the car’s motor. The two potentiometers also serve as safety nets for the car. The controller makes sure that the signals from the potentiometers are equal; otherwise, the controller stops to operate. Understanding the role of an electric car’s controller is fairly easy. Assuming the battery pack is composed of a dozen 12-volt batteries that are wired to create a series of 144 volts. The controller gets the 144 volts and transfers this power to the motor in a direct process. The driver would usually push the accelerator and release it to turn the motor on and off so that a given speed is maintained. The controller also assists in this step so that turning the motor on and off is more convenient to the driver.
? Nissan LEAF electric car charging. Source: Wikipedia/Mariordo
Electric cars contain either DC or AC motor. If the car is on DC motor, it may be running between 96 to 192 volts. There are numerous DC motors that came from electric forklift industry. On the other hand, an AC motor runs at 240 volts with a battery pack of 300 volts. DC motors are much simpler and less costly to be installed. The typical motor will usually be about 20 thousand to 30 thousand watts and a typical controller runs about 40 thousand to 60 thousand watts. Electric cars with DC motors features an over drive of up to 10-to-1 for short periods. The one limitation though is the heat build-up due to overdriving too much which can even self-destruct. Meanwhile, AC installations make room for the industrial three-phase motor which requires motors with easy power rating and specific size. When it comes to the battery, there are significant problems to handle. The lead-acid battery is heavy and weighs as much as 1000 pounds. They are also bulky and have limited capacity. Lead-acid battery packs also slow when charged since the normal recharge duration is between 4-10 hours, of course, depending on the battery technology. Most of all, they are expensive, costing as high as $2000.
Want to know some of the most popular electric cars? Check out this video.
Isn’t this cool? There’s a DIY electric car!