With so much new tech and innovation going into electric vehicles it is understandable for one to become overwhelmed with everything that’s happening. There are obvious examples you see every day and are easily recognisable, like how the inner city is teeming with Teslas. However, with the ludicrous rate of EV development, have you ever simply pondered “technically what is an EV?”. Before everything goes plaid, it’s worth understanding the fundamentals of what makes an EV an EV. As you’ll find out there’s so much more to electric cars, bikes, and everything else than simply batteries and electric motors.
The essence of an EV
Right now, you’re observing transportation evolve before your eyes. Seemingly, there’s a new electric vehicle from a different manufacturer released each and every week, some weeks it feels as if there’s something new released daily. Before we all get swept off our feet with the tsunami of new makes, models, and modes that’s on the horizon, let’s take a step back and establish a bedrock idea of what an electric vehicle actually is.
Currently the trend is to move away from the internal combustion engine (ICE) and toward this innovative alternative known as EVs. Not since diesel and oil started replacing coal fire and steam has the landscape of how we move about changed so much or this rapidly.
To start off with, there are those most frequently used letters – EV. While this is simply an abbreviation of Electric Vehicle, this name tells us much of what is to be expected, a vehicle powered by electricity.
However, with so many differing ideas being brought to market and so many players in the game, “EV” has become more of a generalised umbrella term which captures many sub-categories of vehicles that are not powered by internal combustion, but more on this shortly.
If when you mention “EV” in conversation, most people will automatically conceptualise it as being a car that runs off rechargeable batteries. However, there is a developing trend to differentiate battery powered EVs with their own abbreviation – BEV, or Battery Electric Vehicles. For the purposes of this article and for future publications relating to electric vehicles on this site, any mention of EVs will be referring to electric vehicles with batteries.
EVs represent an increasing chunk of the transport industry and can come in the form of a car, truck, bus, bike, boat, forklift, milk float and many other styles, serving a variety of different purposes.
Regardless of what the shape may be, the essential components that are found in EVs are the same:
- An electric traction motor – delivering primary drive for the vehicle
- A store of electrical energy – a battery
- A motor controller – a means of modulating the electrical energy from the power source into the motor
This is of course a ridiculously simple break-down of EV componentry and one than is open to variation depending on the vehicle. But regardless of how simple the bill of equipment is, EVs have used these same fundamental parts since their inception. And that has been a long time now.
In fact, they have been around in one form or another since about 1830, approximately 50 years earlier than whenKarl Benz’s gas powered, three wheeled car came on the scene. The likes of Robert Anderson (Scotland), Ányos Jedlik (Hungary), Sibrandus Stratingh (Netherlands), Thomas Davenport (United States), Robert Davidson (Scotland), Gaston Plante (France), Thomas Parker (United Kingdom), and William Morrison (Scotland) can all lay claim to have either invented or significantly contributed to the development of the EV. While it will always be a matter of debate when the first EV was actually invented and by whom, needless to say they have been around for almost 200 years.
Having been around for the best part of two centuries, the technology has had time to be refined and improved. Batteries are now more energy dense than ever before, and electric motors have become smaller, more efficient, and have significantly increased output and performance when compared to their 19th century ancestors.
Different Types of EV
While EVs should be self-explanatory, there are in fact several sub-categories which have fanned out into existence, all of which could be considered some form of an EV. However, it is contentious that some types should even be considered an EV in the first place, but they are still encapsulated within this set of alternate power vehicles.
BEV – Battery Electric Vehicle
As mentioned at the beginning of this article, BEV is becoming an increasingly popularised term for referring to an EV that is powered solely from rechargeable batteries.
BEV common components are:
- Electric traction motor
- Motor controller
- Rechargeable battery
Currently Tesla is the most widely known and recognisable example of a BEV. Increasingly, well-established manufactures are now also becoming involved in the production of BEVs. The likes of Audi with their e-Tron GT, and Harley-Davidson with the LiveWire electric motorcycle are recent examples of BEVs now available on the market from old-school manufacturers. Electric bicycles (AKA ebikes), such as Serial 1 which is powered by a Harley-Davidson ebike motor, are also included in the list of BEVs but are on a smaller scale.
FCEV – Fuel Cell Electric Vehicle
The most noteworthy and promising alternative to battery powered EVs are Hydrogen powered vehicles, also known as Fuel Cell Electric Vehicles (FCEVs) or sometimes simply Fuel Cell Vehicles (FCVs). Essentially, it’s thesame concept as a BEV but in place of a battery pack there is a hydrogen fuel cell which, through a chemical process between hydrogen and oxygen, is constantly producing electricity.
However, similar to an ICE vehicle the hydrogen is stored in a tank and this presents a more practical solution when it comes to filling up, taking about the same amount of time to fill as a tank of petrol or diesel.
FCEV common components are:
- Electric traction motor
- Motor controller
- Hydrogen fuel cell
Toyota is one of the biggest proponents of hydrogen powered vehicles and has been for decades. Currently the Miria is the flagship fuel cell vehicle for the Japanese manufacturer and has been in production since late 2014.
PHEV – Plug-in Hybrid Electric Vehicle
Hybrids are a combo of both internal combustion and electric drivetrains. Hybrids in their simplest forms, such as Toyota’s Prius or the Honda Insite, use an ICE as the primary drive for the vehicle and utilise an electric motor and battery power to assist with the mechanical load being put on the engine.
A Plug-in Hybrid Electric Vehicle is the same except with the added functionality of the battery able to be charged from a mains power supply in addition to any electricity generated from the drivetrain.
PHEV common components are:
- Internal combustion engine
- Electric traction motor
- Motor controller
- Rechargeable battery
- Onboard charger
Some examples include the BMW i8 supercar which can run solely off its 3-cylinder turbocharged engine or in combination with its electric motor, with a battery that can be plugged into an outlet and recharged.
E-REV – Extended Range Electric Vehicles
Like the PHEVs just mentioned, Extended Range Electric Vehicles are hybrids. But unlike PHEVs that are more closely related to ICE vehicles, an E-REV is more closely related (technically) to a BEV. It’s essentially an electric vehicle with an onboard power station, known as a range extender, and is a means of charging the batteries to increase the vehicle’s range while on the go.
This range extender is usually a small internal combustion engine but there are now examples of hydrogen fuel cells being used for the purpose. FedEx for example have been retrofitting and trialling hydrogen fuel cell range extenders in a fleet of existing electric delivery trucks for the past few years.
E-REV common components are:
- Electric traction motor
- Internal combustion engine with generator or hydrogen fuel cell
- Motor controller
- Rechargeable battery
- Onboard charger
A recent example was from GM with the Chevy Volt, this was an electric car that featured a small 4-cylinder engine that primarily powered a generator and occasionally the front wheels. The generator would power the electric motor, as well as charge the batteries. It could also be plugged into mains electricity to be charged when needed.
EV Technical Strengths
If there’s one thing an EV does better than anything else, it’s thermal and mechanical efficiency. This means a relatively small amount of electrical energy is lost either as heat energy or mechanical vibrations. In fact, electrically powered cars are approximately 80-85% efficient in terms of their energy usage.
A byproduct of this high level of efficiency is that there is hardly any noise. They are quiet. Some say too quiet, and could potentially be a hazard for pedestrians especially when the surrounding environment is noisy such as in a built-up urban area like a city.
Electric motors can achieve incredible performance relative to their physical size. What this allows is tighter packaging that is not possible with conventional engines. An ebike for instance, can have its electric motor packaged entirely within the hub of a wheel. An electric car can have the motor incorporated within the subframe allowing for great cabin and luggage space. While this physically small footprint is great for tucking away the drive motor, it should be noted that much space is still lost due to battery packs and other associated electronics.
While on the topic of performance, a key characteristic of electric motors is instant torque. In contrast to an ICE that delivers its torque in a linear fashion, i.e. starting at relatively small amounts of Newton meters and gradually increasing as motor RPM increases, an electric motor will have maximum torque at zero RPM, progressively decreasing as motor RPM increases.
While for this article I won’t go into technical details about how an electric motor achieves instant torque, the short answer is that is has to do with the physics of the magnetic fields within the windings of the motor itself.
Regardless of the why, it’s this instantaneous rotational force that enables a Tesla S Plaid to do 0-100km/h in 2.1 seconds and a standing quarter mile in just over 9 seconds.
EV Technical Weaknesses
Without a doubt, the biggest shortcoming of any electric vehicle is the battery. While battery technology has rocketed ahead in recent years and continues to do so, it still falls short in three critical areas: energy density, packaging, and cost. It is such a major shortfall in an EV’s design that it is spurring on the development of the alternatives, such as hydrogen, in an attempt to restore the ease and practicality of simply filling up a fuel tank.
Energy density:
This is the term used to describe how much electrical charge can be put into the physical space of a cell. Manufacturers of batteries and cells such as Tesla, Panasonic, LG, etc. are on a non-stop quest to make their products as energy dense as possible to better utilise the physical space the battery pack occupies.
This is more of an issue for larger vehicles that have longer distances to travel. An ebike for example can easily have a range of 50km with a relatively small battery, more than enough for the average cyclist to be able tocommute between charges. Cars, buses, and trucks on the other hand need to travel much further, usually in the hundreds of kilometres. This means their battery packs need to have enough electrical capacity to meet the required distances of travel. But larger battery capacity means a physically larger battery pack also.
Packaging:
Trying to fit big batteries into cars or trucks is a headache for designers and manufacturers. It’s a tricky balancing act to have reasonable range while still maintaining occupant comfort and vehicle dynamics.
Larger batteries can result in less cabin or boot space. As the pack is (typically) integrated into the floor with the passengers perched on top, this raises the centre of gravity and changes the vehicle’s dynamics and handling characteristics.
Cost:
Most significantly, a big battery drives up the cost of EVs significantly. While EVs are relatively cheap to run and maintain on a day-to-day basis there’s no escaping the fact the initial investment in such a vehicle is significantly more when compared an equivalent spec ICE vehicle. Most of this cost is down to the battery. To replace a battery pack in an EV for instance can represent as much as two thirds of the purchase price of the vehicle, such is the high cost of the pack. While battery prices are coming down thanks to economies of scale, they are still a costly and necessary part of every EV.
Conclusion
Hopefully this is a good introduction to what the fundamentals of electric vehicles are. We have only just scratched the surface as this field is enormous and at times complex. This is just the start of a long journey to learn and understand EV technology in its totality.
Having knowledge of the correct terminology and essential componentry will aid in our understanding of this reinvented approach to vehicle design. The hope is that by having a greater understanding, EVs will seem less of a foreign concept or a far-fetched, futuristic, pipe dream.
There is still so much more to unpack, explore and to learn about. One topic at a time we’ll discover and get into the depths of this innovative technological field. This is truly an exciting period for transportation globally and to witness it unfold in real time will be an exciting ride into the future.
More EV related articles from the author:
Victoria’s Electric Vehicle Duty: More Benefits for EV’s than you might thing…
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