The electric vehicle market has come a long way in the last 10 years due to a number of factors and advancements in technology. Awareness of the dangers of climate change, material science innovations, and improvements in battery energy capacity have paved the way for the electric commuter vehicles we see today.
These vehicles are environmentally friendly, cheaper than gasoline vehicles in both initial cost & fuel and are convenient for travel in tight streets as well as for storing in confined spaces. But what goes into one of these urban travel vehicles? How do they work at a technical level? Let us take the Levy electric scooter to be our example for which this analysis is based on as it is a good representation of the affordability to performance ratio that advancements in technology afford. We’ll consider the electric scooter in 4 parts: The body, battery, motor, and motor controller.
The body is composed of an aircraft grade
aluminum alloy; you may be familiar with this
material if you own a MacBook. Aluminum is light, abundant, and strong. It provides the protection, durability, and longevity of steel while being 2.5 times less dense. This weight saving factor is important especially in an electric vehicle and allows the battery to use less energy in overcoming the inertia of a standstill vehicle. This translates to longer rides and faster acceleration.
The Levy Electric Scooter is unique in that the battery is stored in the front steering portion of the scooter as opposed to under the scooter like most and can be removed and replaced with a fully charged battery. One of the main reasons electric vehicles are even possible are the great advancements being made in battery technology, specifically battery energy density. The battery of choice for most modern devices is lithium ion. These are in your phone, laptop, and now your electric vehicle!
The battery is comprised of an anode, cathode, a separator between the two, and a medium through which the energy can move. The anode and cathode toss lithium ions back and forth between each other, from the cathode to anode when charging and vice versa when discharging. This flow of ions generates electrons, and therefore electricity. By shrinking the space between the anode and cathode we have been able to increase the energy capacity of our batteries while also shrinking them in size. That’s how your phone is so thin, and how you can fit a battery powerful enough to propel a human into the stem of a scooter! This space is filled with a liquid that conducts the ions; in the future we hope that dry cell batteries will become available. This will replace the liquid with a conductive solid and allow for even thinner and more energy dense battery units.
So, what is this battery for? What exactly does it power on an electric scooter? Your lithium ion battery is used to power the motor, of course! There are several different types of electric motors, but for our purposes the brushless DC motor is what is of importance.
Have you ever thought about how an electric motor works? It doesn’t use a driveshaft, such as engines in conventional cars. Electric motors use magnetism to spin what is called the armature. You can see the armature below, it is in center of the Levy’s motor, that little arm sticking up at us. The armature has magnets inside of it. The outside of the motor, all those copper coils, are electromagnets and are called the “stator”. The electromagnets surround the armature in a full 360-degree circle and flip their polarity individually over and over in a circle one after the other so that the magnets in the armature follow it, generating torque. The armature follows the stator because of the opposite poles just like the magnets you use to play with as a kid, except these poles can be manipulated and changed with electric current. See how all that battery talk comes back around?
Finally, how do you tell your computer how fast you want to go? Sure, on your end you just turn a handle or a dial and the thing moves, but what’s going on behind the scenes? To communicate with your motor, electric scooters use what is called a “motor controller”. The motor controller has a circuit board, and through sensors and software, reads incoming data and responds accordingly. For example, your motor controller can read your battery level in order to determine if you have enough power to continue supplying the motor. It reads data from your throttle to determine how much juice to give the motor. It also helps you brake, as it reads data from the various breaking mechanisms on your scooter. Your motor controller is the brains of your device, and without it you wouldn’t be able to communicate with the scooter at all.
The electric scooter is a simple device made of 3 main parts on an aluminum body. Yet it has taken us decades to get to this point to be able to create these devices. It is a marvel of modern engineering, so take advantage of it! Make your commute faster, cheaper, and more eco-friendly. Batteries and ride times are only going to get better so make sure you keep an eye on the electric vehicle market, it’s an exciting time for travel.