With Europe planning to be a ‘Carbon Neutral Economy’ by 2040, the future of mobility is electric.

Out of the different electric vehicles that exist today, electric scooters provide the most promising solution. Besides being more ec0-friendly than other electric transportation alternatives, their portable nature and compact size make them ideal for the urban commute (and definitely a futuraride!).

Today, we’ll try to explain the working mechanism of this amazing ride.

An electric scooter, as the name implies, runs on electricity. It has a battery that stores electric power, which is then converted into kinetic energy by a motor. The main working part or the powerplant of an electric scooter is its motor.

Let’s try to understand how it works!

How Does an Electric Scooter Motor Work?

From acceleration and top speed to the climbing ability, it’s the motor of an electric scooter that determines almost all aspects of its performance. 

Before we take a look at the working mechanism and types of electric scooter motors, let’s see what are the most important things that we may want from them.

Things You May Want From an Electric Scooter Motor

An electric scooter motor needs to have enough starting torque to move the scooter from a standstill.

Let’s Kick via Unsplash

It must have adequate power to take you wherever you want, be it an uphill place. It must also be controllable so as to vary the speed of your scooter as per your requirement.

Most importantly, it must be reliable and durable to last a long time.

Types of Electric Scooter Motor

There are two common types of motors that are used in electric scooters. They are:

Let’s see how each of them works and what advantages does one has over the other.

Brushed DC Motor

A brushed DC motor is a motor in which the electric current is supplied to the electromagnet coils on the rotor via a pair of brushes. The main feature of this motor is that the electricity is supplied to the part of the motor that rotates.

This type of motor was developed back in the early 19th century and is mainly popular due to its low cost and simple operation.

Here’s a diagram of a brushed DC motor, which can help you understand how this motor works. 

Internals of a Brushed DC Motor of Electric Scooter
Internal parts of a Brushed DC motor via Galco

Functional Parts of a Brushed DC Motor 

A brushed DC motor comprises of the following parts:

The Brushes are made of a conductive material that is not abrasive. They are meant to conduct electricity from the source (the scooter battery) to the electromagnetic coil of the rotor. This makes it possible for the electromagnetic coils of the rotor to have a supply of electricity even when they are rotating with reference to the brushes.

The Commutator is generally made of copper or another highly conductive metal. It receives electricity from the brushes and conducts it to the electromagnet windings of the rotor. There are two commutator contacts for every coil in the motor.

The Armature, also called the rotor, is the part of the motor that rotates and converts the electric energy to kinetic energy (motion). It has a bunch of coils of wire wound on it which generates the magnetic field that rotates the motor’s shaft.

The Stator is the housing of the motor that has a permanent magnet in it. This magnet provides the magnetic field that interacts with the magnetic field of the rotor’s electromagnets to rotate the rotor. Some DC motors might have an electromagnet in the stator. In the case of such motors, the stator’s electromagnet draws electricity from the same source as the rotor’s coils.

The Shaft is the output part of the motor where the energy is used to do work, that is rotating the wheel of a scooter.

What Happens When You Turn a Brushed DC Motor on?

When you turn on a brushed DC motor, the following sequence of events happens: 

One thing to note here is that the magnetic field of the rotor’s windings changes direction every 180 degrees of rotation. To keep the direction of rotation constant, the contact between the commutator and the brushes reverses the direction of flow of the current every 180 degrees.

White via Unsplash

In addition to that, the direction of the application of magnetic force to the rotor changes as it rotates. This means that the motor will have different speeds at different points of rotation. This is compensated by having multiple coils in the rotor so that the motor always has a uniform speed and torque output.

What Determines the Power Output of a Brushed DC Motor? 

One of the most important characteristics of an electric scooter motor is its power output. As power in any electric system is the product of the voltage and current, it means that increasing either of these will make the motor more powerful. 

To make a motor more powerful, the windings on the rotor can be increased so that more current passes through them. Increasing the input voltage also increases the power output of a DC motor. Moreover using more powerful magnets can also increase the power of the motor.

Pros and Cons of Brushed DC Motors

Brushed DC motors have certain advantages over brushless motors. These include:  

However, there are some limitations to brushed DC motors too. These include: 

Brushless DC Motors 

Most of the electric scooters nowadays use a brushless DC motor instead. This is mainly because these motors can fit inside the hub of the wheel and don’t need to be mounted on the frame. 

A brushless DC motor (BLDC), as the name implies, does not have brushes to conduct electricity. It has a totally different design and working principle as compared to a brushed motor. This type of motor was developed in the 1970s and is widely popular mainly because of its long life and less noise.

Here’s a diagram of the internal parts of a BLDC motor:

Brushless DC Motor of Electric Scooter
Brushless DC Motor via Renesas

There are two main functional parts of a BLDC motor. They are:

Some BLDC motors might have fixed electromagnet coils in the middle and permanent magnets attached to the stator. In such motors, the stator is what rotates.

How Does a Brushless DC Motor Work?

The working principle of a BLDC motor is simple: you provide electric current to the stator coils and the resulting magnetic field rotates the rotor, which is a permanent magnet. As you can notice, the coils of the BLDC motor do not rotate, there is no need for brushes and a commutator in such a motor. 

However, if the coils are fixed in place, how do you change the polarity of the electromagnet which is required to keep the rotation of the motor unidirectional? That is achieved by using a controller.

The controller either works with a rotor position sensor or with the help of magnets on the body of the motor. Here’s the difference between these two types of controllers:

The need for a controller makes a BLDC motor inherently complicated as compared to a brushless one. However, BLDC motors have a number of advantages that make them feasible for many applications, especially for usage in electric scooters.

Electric scooter
Kelly Sikkema via Unsplash

Factors Affecting the Power Output of a BLDC Motor

The power output of a BLDC motor depends on the following:

Pros and Cons of a BLDC Motor

BLDC motors, also used in ebikes, are better than their brushed counterparts because they: 

However, all of that comes at a price. There are some downsides to BLDC motors too, such as:

It brings us to the next question; what type of motor is better for an electric scooter? 

Which Electric Scooter Motor is Suitable for You?

The answer to that depends on a lot of factors. The most important of them is cost. After that, there is the reliability and complexity factor. But in the end, it all comes down to your personal decision. As we said earlier, both motor types have their own pros and cons.

Electric scooter
Paulo Victor via Unsplash

An electric scooter with a BLDC motor can be a better option for you, if: 

On the other hand, you can go for an electric scooter with a brushed DC motor, if:

Our Verdict on Electric Scooter Motor

If you ask us, we’d say a brushless DC motor is always a better choice for any automobile application including electric scooters. It is because these motors do not need maintenance and run quieter. Moreover, they are more efficient and have finer control over speed and torque output.

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