How Electric Cars Work
Learning how electric cars work can help you better see their benefits and their disadvantages.
An electric car, or battery-powered motor vehicle, is a type of alternative fuel vehicle similar to hybrid cars. The reality of the electric car is much like what it sounds to be – a car that runs primarily from electrical power, rendering it a highly fuel-efficient vehicle. Rather than using an internal combustion engine, which is an engine that relies on the combustion of fossil fuels or other combustible materials, battery-powered vehicles use an electric motor for propulsion, usually in conjunction with a battery pack.
Electric Car Motors
Electric motors of high-class battery-powered vehicles can provide high power-to-weight ratios, and batteries of electric cars have been designed to supply large currents to support these motors; drivers typically report great satisfaction in the torque of the vehicles. Most electric cars operate by using materials found in rechargeable batteries, including lead-acid, nickel-cadmium, nickel metal hydride, lithium-ions, Li-ion polymers, and, less commonly, zinc-air and molten salt. The lithium iron phosphate battery, which is a variation of the same battery technology used in modern cell phones, is currently one of the most promising electric vehicle battery variants due to its light weight, high energy density, and lack of overheating issues that have consistently plagued lithium-ion batteries of the type found in small devices. The amount of electricity stored in these batteries is measured in ampere-hours, or coulombs, with the total energy often measured in watt-hours.
Regenerative Braking Technology
Almost all modern battery-powered vehicles additionally utilize regenerative braking technology, an energy recovery mechanism that extends battery life by partially converting the kinetic energy generated by braking into an electrical charge. This allows the car to recoup some of the energy lost during the braking procedure. Electric railway systems and sport racers have also used regenerative braking technology for the past several years.
The Electric Car Market
Historically, battery-powered vehicles and plug-in hybrid cars (which use a small internal combustion engine to supplement the battery) have been available for nearly as long as combustion engines. Problems encountered in their production, though, include problems with high battery costs, limited availability of charging mechanisms, charge time, and battery lifespan, which have limited their widespread adoption – automakers have referred to consumer angst over these limitations as “range anxiety.” However, ongoing battery technology advancements have reduced many of these problems to surmountable challenges, and a very few major production models announced by worldwide automakers.
Electric Car Batteries
Though heating is traditionally provided through an electric resistance heater (using the heat that the engine produces), this has usually been a problem with electrical cars. As a result, electric cars usually use reversible the more modern reversible heat pump, which achieves higher efficiency and integral cooling.
Batteries in electric cars must be periodically recharged. Most commonly, this is achieved by charging from the power grid at home or using a local charging station. Power for the power grid is generated from a variety of domestic resources, such as coal, hydroelectricity, nuclear, and others. Many early adopters of electric car technology have constructed solar power stations to charge their vehicles; home power, such as roof top photovoltaic solar cell panels. Micro, hydro, or wind power could also be used and are promoted because of concerns regarding global warming. An alternative to this is replacing the battery and leaving it to charge; effectively, this would be much like the Old West standard of switching horses for stagecoaches.
Charging time is limited primarily by the capacity of the grid connection. A normal household outlet is capable of supporting between 1.5 kW (in the US, Canada, Japan, and other countries with 110 volt supply) to 3 kW (in countries with 220-240 volt supply). The main connection to a house might be able to sustain 10 kW, which means charging a car with a small battery would require up to an hour – a stark change from filling up from the pump. Even if the supply power can be increased, most batteries do not accept charge at greater than their charge rate, as high charge rates have an adverse effect on the discharge capacities of batteries. Nevertheless, conventional power outlets are sufficient to charge batteries overnight.
