How to Choose E-bike Motor Controller

When most people hear the term “electric bicycle,” the first thing that comes to mind is a scooter or an electric motorbike, but they are not the same thing. Consider a standard bicycle, then add various electrical components such as a motor, a battery, and a controller – all of which are smoothly incorporated into the design. These components are the foundation of all-electric bicycles on the market!

This new technology Hub Motor DIY Conversion Kit is designed explicitly for Electric Bike Bicycle. This innovation is used for converting your vehicle or cycle into Electric Bicycle.  These are better quality quads and scooters on the market and are classed as a mid-range combination.  A variety of components such as the E-bike. Motor, controller, battery, throttle, brake, and mechanical components are necessary to build an E-bike. In this tutorial, we will discuss how to choose the best E-Bike Motor Controller.

E-bike Motor Controller

The Motor Controller is a crucial component of an E-bike since it controls the E-bike motor. The majority of E-bike motors are brushless and have three wires. This alternating current is required for the brushless motor to rotate. At motor speeds corresponding to cycling speeds ranging from zero to 48 km/h, an electric bicycle controller must supply power ranging from zero to the rated peak of the propulsion motor (30 mph). Power may be adjusted by pulse-width modulated (PWM) transistors in DC propulsion motors.

This motor controller ensures steady speed and sensitive control of braking and direction changes in an electric bike bicycle. The controller body/shell is made up of a high-quality aluminum alloy that protects the inner circuit. Hence this premium shell is good for heat dissipation to avoid thermal overloading. Meanwhile, the controller wires and interfaces offer high durability, thereby ensuring malfunction after a long time of use. Moreover, it provides a Current limiting feature that prevents controller and motor damage due to over-current conditions. The controller board comes with attachments for the motor, accelerator, brake, battery, brake light, and power lock.

. Moreover, this controller features:

  • Anti-coaster and over-current protection
  • Automatic identification of the 36V and 48V
  • Automatic identification of the Hall sensor
  • Phase angle identification of 60 degrees and 120 degrees

Pedal-activated controls provide electric assistance when you depress the pedals. A controller positioned on the handlebar in pedal-activated systems allows you to regulate the degree of assistance based on your pedaling.

Throttle-based controllers use a straightforward throttle mechanism. It functions as a potentiometer. The throttle might be of the twist-grip or thumb-press kind. With a throttle, you may obtain electric assistance by pulling back or pressing the throttle.

Functions of the E-Bike Controller

The controller’s real task is to accept inputs from all of the E-bike components, such as the throttle, battery, speed sensor, display, and motor, and determine what signal should be returned. Multiple safeguards are included in the various controller designs, including:

  • Low-voltage Protection– The controller continuously checks the battery voltage and turns down the motor when the voltage falls below the cut-off point. It will safeguard the battery from over-discharge.
  • Over-voltage Protection– The controller also keeps track of the battery’s charge level. When the battery voltage hits its maximum, it will shut off automatically.
  • Over-temperature Protection– The controller keeps track of the FET’s temperature (Field-effective Transistors). When the motors become too hot, it will shut them off.
  • Over-current Protection– The controller decreases the current flow to the motor if the motor requires additional current. It protects both the motor windings and the FET power transistors.
  • Brake Protection– When compared to other signals, the controller prioritizes the braking signal. If you press the brakes and the throttle at the same time, it will perform the brake function.

Types of E-bike Controller

Brushed DC motor controllers, brushless DC motor controllers, and BLDC motor controllers with hall sensors are the three types of E-bike controllers available. Let’s take a closer look at these

1. Brushed DC motor controllers

Brushed DC motors come with permanent magnets to go with a connector. These controllers have a significantly simpler design. It’s merely a set of keys that allows you to modify the amount of current fed to the engine.

Brushed controllers are commonly seen on scooters, electric bicycles, pedelecs, e-bikes, and other light electric vehicles.

These controllers are pretty simple to use and are mostly used by DIY hobbyists and enthusiasts. The above image shows the set of the brushed motors with controllers.

2. Brushless DC motor controllers

An E-bike, Mostly BLDC motor, and BLDC controllers are used. These are the brushless motors with permanent magnets. They’re reliable, and they’re more efficient. These controllers are extremely easy to use and maintain. Everything about brushless DC motor controllers, including their operation and maintenance, is straightforward.

A Brushless motor with a controller is shown in the image above. It resembles brushed controllers in terms of construction. Brushless controllers have three phases, each of which is controlled by a set of keys and at least two transistors (key/MOSFET). These keys are all multiples of six (like 6, 12, 18, etc.).

3. BLDC controllers for motors with Hall Sensors

Brushes in brushed DC motors make contact with the commutator and switch the current for rotor movement. The BLDC motor, on the other hand, has no brushes. As a result, they must be controlled electrically using a motor control system.

A Hall Effect Sensor is a transducer that works on the Hall Effect principle. The location of the rotor is determined using Hall Effect sensors in relation to the stator. The stator is the motor’s stationary component, while the rotor is its revolving component. It also calculates the speed and other characteristics needed to efficiently drive a BLDC motor. These sensors, also known as Rotary encoders, are used to determine the rotor’s position.

Need for this sensor?

To push the rotor again after one rotor movement, we must switch a certain winding on. Because the Hall Strip always has a little amount of current flowing through it, it decides when we need to push the rotor. Due to this, the next commutation of the rotor can be initiated.

How to Choose E-bike Controller?

The following factors need to be considered to choosing the perfect E-bike controller,

  • Controller Voltage & Power

Check the controller voltage and power if you’re choosing a controller for a specific motor. If you acquire a non-programmable controller, be sure that the control voltage matches the motor voltage and that the controller power matches or exceeds the motor power. If the motor voltage is 24 volts, the controller voltage should also be 24 volts.

If your controller is programmable, you can limit the power if necessary. The controller’s voltage should be compatible with both the motor and the battery. This consideration will lower the controller’s heating and make its operation more steady, increasing the system’s reliability.

  • Controller Current Rating

Make sure the controller’s current rating is less than the battery’s output current when choosing a controller. A 9-MOSFET controller’s maximum current is typically 25A, 18A for a 6-MOSFET controller, 40A for a 15-MOSFET controller, and so on.

  •  Phase and Battery Current

The phase current and the battery current are sometimes confused by newcomers. These are two distinct concepts. The motor is connected to the phase current. The phase current can easily exceed the battery current.

When selecting an E-bike controller for the motor, make sure the phase current of the controller and the motor current are compatible. If the controller gives more current than the motor’s current capacity, the motor will overheat.

The varnish coating on the wires begins to lose its quality when the motor overheats. As a result, a short circuit occurs, and the motor rapidly warms up, damaging the windings.As a result, with standard E-bike controllers, the controller’s phase current must match the motor current. Individual components will not fail as a result of this arrangement.

  • Controller Driving Type – Sine wave or Square wave controller?

The phase voltage waveform of both controllers is different. One creates a rectangular waveform, while the other creates a sinusoidal waveform.

Sine wave controllers are popular because they produce less noise. As a result, when climbing a hill or carrying a large burden, it is more efficient. These controllers also give smoother and more consistent control over ordinary activities. Sine wave controllers, on the other hand, use a lot more power and are more expensive. Furthermore, they can only work with motors that are matched.

Square wave controllers are more popular since they are less expensive. They can work with a variety of motors. These controllers are more efficient while braking or accelerating suddenly.

They produce a lot of noise and non-smooth or punched control when compared to sine wave controllers. When traveling uphill or carrying a large weight, square wave controllers are also less motor efficient.

  • Is it a Hall Sensor/Non-Hall sensor drive or a Dual-mode controller?

The controller should be Hall-sensor or dual-mode if your E-bike motor has a Hall sensor. The motor’s hall sensor detects motor rotation, and the controller generates a voltage based on the sensor signals. This controller is more stable, uses less power, and has a higher beginning torque.


Electric bikes can assist riders of all ages, skill levels, and physical capacities to lead more active lifestyles, but they are not without flaws. Being aware of the benefits of ebike use, as well as some of the problems associated with purchasing and operating an ebike, will make you a well-informed, knowledgeable consumer, ready to make the best possible decision when it comes time to pick and purchase your own ebike.

Hope this blog helps you to understand how to choose the best E-Bike controller for your E-Bike. We, MATHA ELECTRONICS  will come back with more informative blogs.

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