Contrary to popular belief, electric cars aren’t actually new. The technology has been here from as far back as 1884. Due to limitations in technology, electric cars are largely a lost subject, in favour of petrol and diesel fuelled vehicles. Now that the world has realized the role of petrol and diesel vehicles in pressing issues such as climate change, the focus has returned to electric car technologies. Electric cars in general have a better fuel economy and produces less emissions compared to traditional gasoline-powered vehicles.
Electric cars are all the rage these days. It would be hard to avoid news about the electric revolution in the automotive world, with companies such as Tesla spear heading continuous innovations in the field. Electric cars have seen a massive increase in their sales, with renowned automotive companies such as Jaguar and BMW joining in on the trend.
In this article, we are going to explain the A-Z of electric cars, what they are and how they work.
What is an Electric Car?
With so many innovations to keep up with in the automotive world, it is easy to lose track of what an electric car really is. Simply put, an electric car or electric vehicle (EV) uses an electric motor that takes its power from transportable sources of electric current such as fuel cells and batteries.
It can be easy to confuse full electric vehicles with hybrid vehicles. A full electric vehicle uses the electric motor as the only source of power. Meanwhile, a hybrid vehicle uses the electric motor in conjunction with the traditional internal combustion engine as power.
You may have heard of ‘BEVs’ a lot in automotive news. It stands for battery electric vehicles where the source of electric current is a battery. Generally, when referring to ‘electric vehicles’, many people refer to both BEVs and fuel cell vehicles.
How Electric Cars Differ From Traditional Gasoline-Powered Vehicles
The main distinction between EVs and regular vehicles is that an electric motor replaces the internal combustion engine that is found in traditional vehicles. In electric vehicles, there are also no gears or clutches. They just use electric current to change the speed of the motor.
Because there are no liquid fuel sources for a full electric vehicle, you also find the other fuel associated parts found in gasoline vehicles such as intake manifolds, gas tank, carburettors, gas pumps and exhaust pipes.
Electric cars also have less moving parts, so in some ways, it reduces maintenance work. The only moving part in them is the rotor.
Electric cars generally use electronic controls over mechanical methods of controlling actions, unlike in conventional vehicles. Starting, stopping and changes in speed are all controlled electronically.
Even though electric cars on their own produce less emissions than traditional vehicles, they also have more methods of saving energy, such as regenerative braking. The purpose of regenerative braking is to recover energy from the momentum during a car’s deceleration, which would otherwise be lost as heat. This feature is not available in conventional gasoline-powered cars. Additionally, in most electric cars, the power is turned off when the car is in ‘idle’ such as during traffic.
Because they have many methods to conserve energy, they tend to have a better fuel economy than traditional vehicles.
Basics of How Electric Cars Work
In one sentence, it can be said that, direct current drawn from a battery or fuel cell is used to run the motor and propel the vehicle.
Electric cars work by converting direct current drawn from a fuel cell or battery to alternating current using an inverter, and then using this AC current to turn an induction motor. The induction motor is turned by the alternating current producing an alternating magnetic field. The turning of the motor is then used to propel the vehicle.
The source of the direct current is a battery pack. A battery pack is made from a series of around 7,000 lithium ion cells that work together to generate direct current.
The drivetrain found in electric vehicles is not as complicated as in traditional vehicles. Electric vehicles use a single speed transmission that delivers the power from the motor to the wheels.
To change the speed of the vehicle, a signal is sent from the accelerator pedal to the controller. This will change the speed of the vehicle by changing the frequency of the AC electric power from the inverter to the motor.
Battery Electric Vehicles use rechargeable batteries that need to be charged regularly, much like fuelling up at a gas station. The battery can be charged by simply plugging into an electric outlet, at home or at an electric vehicle charging station.
Charging an EV
There are many ways of charging the battery of an EV. When charging at home, a 120 V outlet is needed. One hour of charging is enough to give about 2-5 miles of mileage. This is the slowest method of charging.
The second method is to use an EVSE (Electric Vehicle Supply Equipment) which could be done at home or a charging station. The EVSE operates on a 220/240 V circuit and can be used on all plug-in vehicles. This is faster than using a standard 120 V outlet, and an hour of charge can cover 10-25 miles of distance.
Finally, the fastest method of charging an EV is to charge at DC fast charging station where they use DC-based EVSE. This method can be used for all plug-in electrical vehicles. Here, 80% of the charge will be completed in 30 minutes.
Regenerative Braking
As mentioned before, electric vehicles attempt to conserve energy by recovering energy that would otherwise be lost during braking. The loss in energy is mostly due to friction between the wheels and road surface. The loss in kinetic energy during braking is converted into electrical energy via the induction motor. How does this happen? Well, in electric and hybrid vehicles, the motor turns in the reverse direction when the driver brakes. When the motor operates in the normal, forward direction it converts electrical energy to rotational kinetic energy. When the motor operates in the reverse direction, it does the opposite. It converts the kinetic energy from braking into electrical energy, acting like a generator. This generated electricity is stored for future use in the battery pack.
The Anatomy of a Battery Electric Vehicle (BEV)
Electric car technology is evolving at a fast rate, so the exact anatomy or technology would depend on the specific car. They all have different features such as self-driving technology, but here we are describing the basic anatomy of most electric vehicles.
Contrary to what people may think, the anatomy and operation of an electric vehicle is usually simpler than that of a traditional vehicle. There are not as many moving parts, so the structure of an electric vehicle is simpler.
The key components of electric vehicles are:
1. Electric Motor
Every electric vehicle uses an induction motor. AC current generates changing magnetic fields in an induction motor, which will make their poles turn and turn the motor. Technically, these can run on either DC or AC, but AC motors tend to be lighter and simpler and hence are more common in electric vehicles in the market.
2. Motor Controller
A motor controller is to an electric motor what the brain is to the heart. It tells the motor what to do. It is also the intermediary between the battery and the motor. Any speed change has to go through the controller as a signal, to the electric motor. The controller helps monitor the performance of the key components of the car, such as the accelerator pedal, the battery and the motor. Hence, it effectively controls all the key tasks of the car. Motor controllers can operate on either AC or DC current.
3. Batteries
This is the most important power source of an electric vehicle. There are many types of electric vehicle batteries available, such as:
- Lead Acid Batteries
This is the cheapest of all the battery types and hence are quite popular in the electric car industry. They are also 97% recyclable.
- Lithium-Ion Batteries
Performance wise, these are the best batteries and also the most lightweight. They are widely used in the electronics industry for things like laptops and smartphones. They are durable and give a higher range and have longer lifespans than lead acid batteries. However, they are also the most expensive of all the battery types. Also, there are some concerns about their toxicity.
- Nickel Metal Hydride Batteries
These have a higher energy density than lead acid batteries but are less efficient in the charging and discharging process. They are appearing to be the biggest contender to lithium ion batteries because they are less toxic and more economical.
Batteries can be charged via several methods. They are chargeable both at home or at specialized charging stations. Batteries also charge via regenerative braking available in electric cars, but it’s usually not enough to completely charge it.
The battery pack consists of many individual battery cells that work together to generate current and store electrical energy. The battery pack is one of the heaviest components of an EV and is normally quite low down in the vehicle, so as to maintain the car’s centre of gravity as close as possible to the ground.
4. Inverters
The current drawn from the batteries is in DC, while most of the motors found on EVS operate on AC current. So, there has to a way of converting the DC current to AC current which is what the inverter does.
Advantages of Using Electric Vehicles
Greater Efficiency
Electric cars are far more efficient than regular vehicles because electric motors are generally more efficient than internal combustion engines. Electric motors are around 80-90% efficient while internal combustion engines are only around 30% efficient. In internal combustion engines, most of the fuel’s energy results in the production of heat, which is waste.
Due to this vast improvement in efficiency, electric vehicles have a better fuel economy than traditional vehicles, which of course means major savings in fuel costs per year. For example, the fuel cost of running 30,000 miles for a Tesla Model S comes to about $1,048 annually, while at the same time the average annual fuel cost for a traditional car is about $5,318.
Equal or Greater Performance
EVs can sometimes outperform even the best traditional vehicles. This is because electric motors can generate high torques at lower engine speeds, which is not possible on internal combustion engines.
EVs are also smoother and quieter when running.
Less Air Pollution
As mentioned, electric motors are more efficient than internal combustion engines. Hence, they inherently have a better fuel economy as they waste less . They also don’t produce any emissions at all. They have additional energy saving mechanisms such regenerative braking. So, they waste less energy and pollute the air less.
Maintenance
EVs have less moving parts compared to traditional vehicles. This means less parts are likely to fail and hence require less maintenance work.
Electric Vehicles are an innovative automotive technology helping to tackle our pressing issue of climate change. They are more efficient and cause less air pollution. However, the technology is relatively new and limitations of them are preventing them from taking over gasoline powered cars. For example, the battery packs are quite expensive and heavy which might cancel any benefits from fuel savings. It’s also easier to find a gas station compared to an EV charging station. So gasoline cars are still more convenient.
