Definitive Guide to Electric Cars
Definitive Guide to Electric Cars
What is an Electric Car?
When people talk about “electric cars,” they’re most likely referring to a battery electric vehicle (BEV). BEVs are just one variety of the broader electric vehicle (EV) universe. What sets BEVs apart is that they run purely on electricity. No gas required! BEVs are able to do this by storing energy in rechargeable batteries and using electric motors (at least one, maybe more) to power the vehicle.
There are two other types of EVs that are commonplace here in North America: Hybrid Electric Vehicles (HEV) and Plug-In Hybrid Electric Vehicles (PHEV).
HEVs are gasoline vehicles that are assisted by the boost of a rechargeable battery but don’t get plugged into a power source to recharge. Instead, HEVs recharge their batteries automatically as you drive. (More on that later.) PHEVs, as the name implies, do have batteries that can be plugged in and charged.
How Does an Electric Car Work?
Let’s start by breaking it down into the individual parts.
The battery is the physically largest component and arguably the most important. The “traction battery pack” stores all of the electrical energy needed by the car and powers its components. Most modern EV batteries are made from lithium because they can store high levels of energy while also remaining relatively lightweight. Assuming every EV has the same electrical efficiency, it would be fair to say that a bigger battery means more electric range. Because they run only on electricity, BEVs tend to have the largest batteries, followed by PHEVs then HEVs.
Using the electrical energy stored inside the battery pack, the electric traction motor converts that energy into mechanical energy. The vehicle’s electric transmission then transfers mechanical energy from the motor to drive the wheels. Depending on the number and placement of these motors, a BEV’s drivetrain can either be front-wheel drive (FWD), rear-wheel drive (RWD), or all-wheel drive (AWD).
The electric motor inside a BEV is also responsible for a useful energy recovery mechanism called “regenerative braking.” This occurs when the driver takes their foot off the accelerator pedal, causing the motor to act in reverse and convert the car’s forward motion ("coasting” in gasoline cars) into electrical energy. The energy is then stored in the battery and ready to power the motor again. In other words, this mechanism is able to recover energy that would otherwise be wasted and direct it into the battery so that the car can use it again the next time the driver needs power. If you would like to read a more in-depth discussion on how electric motors work, feel free to skip ahead to “Breakdown of Electric Car Motors.”
Charge Port & Onboard Charger
In both BEVs and PHEVs, the battery pack is charged using an external power source. To recharge, a charging plug is inserted into the car’s charge port. Think of the charging plug as the EV equivalent to a fuel nozzle at a gas station. Similarly, the charge port is the EV equivalent to a gas cap – where a fuel nozzle is inserted during refueling.
Working in tandem with the charge port is the onboard charger. Think of this as the computer system responsible for converting the charging plug’s electrical current into an acceptable power level to charge the battery. Whether it’s AC (Alternating Current) – like the kind of power in our home wall outlets – or DC (Direct Current) – like the kind available at public fast charging stations – the onboard charger does the thinking and converting so the driver doesn’t have to. This ensures the battery is not harmed accidentally by using the wrong type of charger.
Pros and Cons of Owning an Electric Car
For the sake of simplicity, let’s think of electricity as fuel, the rechargeable battery pack as the fuel tank, and the electric motor as the internal combustion engine (ICE) – the type of engine in a traditional gasoline car.
One of the biggest bonuses of buying a BEV over a gas-powered vehicle are the significantly lower maintenance costs. Electric motors have fewer moving parts than gas engines, making them simpler to maintain and likely to last longer. The motor’s regenerative braking functionality naturally helps to slow the car down when it’s not accelerating so the brake system in BEVs doesn’t suffer as much wear. Even traditional replacement parts and refillables such as oil, spark plugs, and filters — all of which are crucial elements to gas vehicles — are irrelevant to BEVs. Think about how many trips to the mechanic you could avoid and how much money you could save over time simply by driving electric!
BEVs also have cheaper fueling costs. Most utility providers offer residential electric rates that cost only a few cents per hour, with some even offering special lower EV rates, such as off-peak rates or time-of-use rates, to reduce fuel costs even further. The price of electricity is much more stable when compared to gas or diesel – experiencing virtually no major fluctuations over the last 20 years. If you are somebody who drives on a near-daily basis, the accumulated savings in fuel costs from making the switch to a BEV can make a huge impact on your household budget.
BEVs are, on average, over twice as efficient as gas vehicles. While gas vehicles are only able to convert about 12 - 30% of the energy stored in gasoline into driving power, BEVs are able to convert over 77% of the electrical energy from the grid to power the wheels. The Environmental Protection Agency (EPA) uses a statistic to compare EV efficiency called miles per gallon equivalent (MPGe), which is defined as the number of miles a vehicle can travel given the equivalent amount of energy that would be contained in a single gallon of gasoline. As of 2018, the average MPG of a traditional gas vehicle was around 24.7 while the average comparable MPGe of BEVs was 100 or higher, making them around four times as efficient as gas vehicles.
A little-known fact about BEVs is that they create less noise pollution than gas vehicles. The amount of noise emitted from an electric motor is significantly quieter than an internal combustion engine and its exhaust system. In fact, there have even been concerns from safety campaigners about EVs being too quiet. By September 2020, U.S. regulators will require HEVs, PHEVs and BEVs to produce their own sounds when driving up to speeds of 18.6 miles per hour. This law is meant to help pedestrians who might be blind, partially sighted, or otherwise distracted to hear them as they approach. As EVs become more mainstream, noise pollution caused by transportation will likely fade away!
Drawbacks of Owning an Electric Car
Despite these superiorities, however, no vehicle is perfect and BEVs face their own share of problems. Like many other electronic devices, the biggest drawback of a BEV is that it will eventually require a battery replacement.
To solve this issue, federal regulations have mandated that automakers cover the battery of their BEVs with a warranty of at least eight years / 100,000 miles, whichever comes first. Some automakers even take this mandate a step further and cover battery degradation. For instance, if your fully charged BEV is rated to provide 100 miles of range and you are only receiving about 70 miles per charge within the timeframe of the warranty, you can qualify for a complimentary replacement. But if your warranty expires, the out-of-pocket expenses for replacing the battery could cost more than $5,000.
The hardware for EV batteries is becoming cheaper each year, so replacement will likely be less expensive in the future. Each BEV comes with its own exceptions, so always read the warranty’s fine print or ask your local associate if you have questions about a certain vehicle.
But What About the Upfront Cost?
All of the added technology in electric cars comes at a price. The reality is that BEVs generally have higher manufacturer suggested retail prices, or MSRPs, than most gasoline vehicles. This is mostly due to the high cost of the battery. However, because of all the environmental and societal benefits BEVs have, the federal government has provided yet another solution to help drive adoption of EVs by providing financial incentives that lower their total cost.
Eligible EV consumers can receive rebates, tax credits, exemptions or driving perks should they choose to purchase or lease an EV. These incentives are offered at all levels of government (federal, state, local) and even by certain companies or agencies, such as utility companies and air quality management districts.
Arguably the most well-known incentive is the Federal Qualified PEV Tax Credit, which offers up to $7,500 off the MSRP of eligible vehicles. The best part about incentives is that these savings have the ability to stack on top of one another. For instance, if the starting MSRP of a 2020 Nissan LEAF is $31,600 and you qualify for a $2,000 incentive that was offered by your state, city and local utility, you would be entitled to a total savings of $9,500 off of your vehicle purchase — that’s a brand-new Nissan LEAF for around $20,000! Be sure to ask your local associate about what incentives you qualify for or check out our guide on Tax Credits & Incentives.
Electric Car Manufacturers
The future of legacy automakers has been challenged within the past couple of decades by a certain company. Of course, we’re talking about Tesla — the company that has single-handedly disrupted the automotive industry ever since it led the charge (pun intended) on commercializing BEVs. Tesla’s vehicles can be found in countries around the world, and the company has even influenced several start-up automakers in creating their own EVs.
A couple of examples in the U.S. include Rivian, a company founded in Plymouth, Michigan, that is currently making waves in the EV community with their electric pickup truck; and Lucid, a company founded in Newark, California, that specializes in luxury electric cars. But Tesla’s impact doesn’t stop there!
Legacy Automakers & Future Commitments
Legacy automakers, feeling the pressure from Tesla, have quickly started transitioning more and more of the product lineup to BEVs. Popular models such as the BMW i3, Chevrolet Bolt EV, Nissan LEAF, and Audi e-Tron have all created their own success stories within the EV market. Even some of the relative latecomers are now among the top selling BEVs in the United States. Automakers such as Hyundai, Kia, and Toyota have become very active in the EV space by introducing numerous PHEV models to their lineup.
Within the past few years, the world has heard these automakers announce their commitment to EV production and their willingness to invest billions of dollars into new sustainable technology. For instance:
- In 2015, Audi announced the automaker’s commitment to achieve at least 25% of all U.S. sales from EVs by 2025. Currently the e-Tron is Audi’s only available BEV in the U.S., but the Audi e-Tron Sportback is looking to change that in 2020.
- In 2017, Nissan announced its new partnership with Japanese-automaker Mitsubishi and French-automaker Renault to build 12 new BEVs and invest $11.5 billion to develop new powertrains.
- In 2017, General Motors also announced that it will be developing 20 all-new EVs by 2023. Be sure to look out for the new 2021 Chevrolet Bolt EV and Bolt EUV crossover next year!
- In 2018, Ford announced that it would invest $11 billion in EV production and have 40 EVs in its lineup by 2022. Ford is committed to keeping that promise by recently unveiling their newest all-electric SUV: the Mustang Mach-E, which is set to hit dealerships as soon as Fall 2020.
And that’s only a handful of them! If you are interested in discovering which vehicle is right for you, please check out our guide for the Best Electric Cars and Hybrids for Your Lifestyle!
Are Electric Cars Better for the Environment?
There are three aspects that need to be considered when evaluating the impact that BEVs have on the environment: tailpipe (direct) emissions, wheel-to-well emissions, and electricity sources. The impact on tailpipe emission reduction is simple: since BEVs lack an exhaust system, they produce zero tailpipe emissions. The other kinds of emissions are a little more complicated.
Wheel-to-well emissions is an umbrella term used to incorporate all emissions related to the production, processing, distribution and use of electricity. Most electric power plants produce emissions and there are additional emissions associated with every step of the energy source’s production cycle. BEVs emit an average of 4,100 lbs of carbon dioxide (CO2) equivalent each year while traditional gasoline vehicles emit an average of 11,435 lbs of CO2 equivalent each year — that’s more than double the emissions of BEVs.
The amount of wheel-to-well emissions that a BEV produces is largely dependent on geographical location and the preferred energy source of that area. For instance, if you charge your BEV in Colorado, you will likely have higher wheel-to-well emissions than somebody charging their vehicle in Massachusetts, because a majority of Colorado’s electricity is fueled by coal where Massachusetts prefers cleaner natural gas as its primary energy source. It’s difficult to say which state is better, because most areas in the U.S. currently use a mixture of resources to generate electricity. Overall, the best way to maximize the environmental benefits of a BEV and minimize its associated wheel-to-well emissions is by sourcing electricity from renewable energy. If you are planning to purchase a BEV in the future and want to lower your wheel-to-well emissions, consider asking your local utility or community choice aggregation (CCA) about any special programs or offers available. You could also consider installing solar panels.
The Global Impact of Electric Cars
Since the transportation sector continues to be responsible for a significant source of air pollution and greenhouse gas emissions, studies show that EVs can help tackle climate change and contribute to better air quality. In fact, simulation models have shown that widespread EV adoption would aid in the fight of limiting global warming by at least two degrees Celsius, which would meet a target of the 2016 Paris Agreement. Nine countries, including the U.S., have currently announced their intent to restrict or ban the use of all internal combustion engines and reduce national tailpipe emissions to zero at some specified year in the future. As fossil fuel reliance decreases over the years, wheel-to-well emissions of BEVs could also see a decrease of at least 73% by 2050, nearly reducing the total emissions of BEVs to zero.
The Environmental Impact of Lithium Mining
The environmental impact of mining for lithium also continues to be a topic of debate. More than half of the world’s reserves are found in the brine of salt flats within an area known as the Lithium Triangle: a massive region in South America that spans across the countries of Bolivia, Chile and Argentina. Over the past few years, mining in these areas has intensified due to the increased global demand for lithium, which is prevalently used in the batteries of many electronics, such as smartphones, laptops and medical devices. With EVs on the rise in many developed countries, the price of lithium batteries is expected to drop as more mining occurs to meet this rising demand. But excessive mining is not without its consequences.
To mine for lithium, holes are drilled into salt flats and large amounts of water are pumped into the holes to churn up the brine and push the mineral-rich liquid to the surface into large salt ponds. The sun then evaporates the water in these ponds and leaves the minerals behind. One of the biggest problems with this procedure is that it depletes the local water sources and permanently damages nearby ecosystems. In Chile, meadows and lagoons near these salt ponds have shrunk over the years, making it difficult for local farmers and traveling shepherds to provide for themselves and feed their livestock. The area’s transformation has also contributed to the decline of the flamingo population due to the lack of available water and grass in the local ecosystems. Even without purchasing a BEV, a simple eco-friendly habit goes a long way — recycle your electronic batteries to help offset the demand for imported lithium!
Are BEVs better for the environment than gasoline vehicles? Yes, but it has yet to become a 100% sustainable solution. Without a doubt, BEVs are headed down the correct path towards eco-friendly transportation, but issues surrounding the continued reliance of fossil fuels and increased mining for lithium must first be solved to make this technology truly sustainable. It is ultimately our duty as consumers to embrace positive change and do our civic duty to lower our transportation emissions while practicing environmentally friendly habits.
Should I Buy a Used Electric Car?
Buying a used BEV is a great choice for many reasons, but similar to new BEVs, you need to consider a vehicle that fits your budget and lifestyle. Here are some key benefits and tips to help with your decision.
- Used BEVs can potentially have like-new batteries. Because range degradation can be a common issue with used BEVs, always check the condition of the battery. The best way to tell if the battery is in good shape is to go to a reputable EV mechanic and ask them to run an on-board diagnostic. Always make sure that the range is enough to fulfill your day-to-day transportation needs!
- Used BEVs have a chance of being covered by the warranty. Always ask about the vehicle’s warranty! Some automakers provide warranties that could potentially protect the vehicle for battery degradation (which we know can be a common issue with used BEVs). Depending on the seller and the automaker, a vehicle may come with an extended factory warranty that functions identically to the original.
- Buying certified pre-owned comes with a higher chance of scoring the previous benefits. This will likely be a pricier option than non-certified vehicles, but you’ll gain greater peace of mind knowing you secured a safer deal.
Detailing How EV Motors Work
Power Electronics & Auxiliary Systems
Let’s talk about another important component inside electric vehicles – the power electronics control system. The primary function of the power electronics controller is to manage the flow of electrical energy delivered by the traction battery to the electric motor. The controller accomplishes this by managing the speed at which the motor turns or by controlling the torque the motor produces.
The secondary function of the power electronics controller is to distribute electrical energy from the traction battery to the auxiliary vehicle systems, such as the lighting, heating, ventilation, and infotainment systems. Rather than the traction battery, a separate auxiliary battery – identical to the ones found in gasoline vehicles – is responsible for powering these systems. This 12-volt battery is kept charged by the DC/DC converter, which converts high-voltage DC power from the traction battery into the low-voltage DC power required to power the auxiliary systems. Therefore, technically, the traction battery powers all the auxiliary systems, too.
When it comes to auxiliary systems, the vehicle thermal management system deserves to be mentioned. One of the biggest determining factors of a safe, long-lasting and functional PEV battery is its ability to effectively maintain a uniform temperature distribution across its cells. Since traction batteries are designed to only operate between a certain temperature range, they will cease to work if there is no thermal system to monitor it. The main function of the thermal management system is to keep the traction battery within this specific temperature range. When an EV accelerates, the battery’s electrical energy is discharged and heat is generated inside the battery. Since acceleration is often the primary method of discharging the battery, without a proper cooling system the battery will quickly overheat and lead to deterioration.
Indirect Liquid Cooling
Several types of thermal management systems are available on the market, but we will only be discussing indirect liquid cooling systems because they are the superior choice. Most modern PEVs are manufactured with indirect liquid cooling systems for several reasons:
- They are highly efficient systems
- They can store large amounts of heat energy
- They are currently the most compact and lightweight solution
As the name implies, the liquid coolant in this type of system does not have direct contact with the vehicle battery. It is instead circulated through a series of metal pipes either surrounding the battery or embedded between the battery’s cells to transfer the heat away. This method allows the cooling system to consume a small amount of energy from the battery to keep it at an operable temperature. In other words, more of the battery’s energy can be devoted to powering the motor and maximizing the powertrain’s performance all the while being uninterrupted by the weight of the system.
Breakdown of Electric Car Motors
Before we can understand how a three-phase induction motor works, we have to break it down into its two main components: the stator, which is the stationary part of the motor, and the rotor, which is the moving part of the motor.
The stator consists of three parts: the stator core, conducting wire and frame. The stator core is built by stacking thin, laminated rings and forming them into a hollow cylinder. This cylinder has slots in the hollow interior that allows the conducting wire (typically made of copper) to wrap around and shape the coils. For a three-phase induction motor, a different wire type exists for each of the three phases that forms its own individual coil. The stator core and the coils are both found within the frame, which is simply the exterior of the entire motor.
The rotor also consists of three parts: the rotor core, conducting rods and two end rings. The rotor core is built by stacking thin, laminated discs and forming them into a solid cylinder that has what appears to be a rod running through the center of it. On the exterior of the rotor core, there are similarly shaped slots to the stator core, but these run diagonally across the cylinder instead of parallel to the rod in the center. The alignment of this rotor’s exterior slots is known as a squirrel-cage rotor, which is a popular design choice among many industries. Along these diagonal lines of the rotor core, the conducting rods are inserted, and the end rings are placed on both sides of the core to lock the rods in place. The rotor then slides into the hollow stator core, and two end bells are placed on either side of the rotor core’s center rod. Now that we have a firm understanding of the components inside an induction motor, let’s see how it functions inside the frame of an EV.
How Does a Motor Work in an Electric Car?
First, we begin with the traction battery that is connected to the motor. As previously mentioned, all of the vehicle’s power is derived from the battery. The electrical energy from the battery is supplied to the motor via the stator. The three copper coils within the stator core are arranged 120 degrees apart from each other and act as magnets. Think of these coils arranged in a “Y” formation. As electrical energy is supplied to the motor, the coils produce a rotating magnetic field that induces current through the connecting rods of the squirrel-cage rotor, thus causing the rotor to spin. This spinning rotor is what creates the mechanical energy needed to turn the wheels of the car. Now let’s pull everything together: when you press your foot on the acceleration pedal, the traction battery powers the motor with electrical energy, which produces the rotating magnetic field in the stator, which spins the rotor via induction, which produces the mechanical energy needed to rotate the tires.
Let’s introduce another new component called the alternator. In terms of traditional gas vehicle components, alternators are responsible for charging the 12-volt battery while the engine is running. This is the reason why you are recommended to drive your car for a while after you receive a jump-start — the battery needs to be recharged to function again. In BEVs, however, the induction motor also acts as an alternator when you release your foot off of the acceleration pedal. During this time, the magnetic field will stop rotating and the rotor will remain spinning until it eventually stops as well. Therefore, regenerative braking will recharge the battery whenever the rotor’s rotational speed is greater than the magnetic field’s rotational speed.