How do I keep my e-bike controller cool?

How do I keep my e-bike controller cool?

 Electric bikes have attained a lot of popularity among the populace, boosting their production and new investors investing in them. This resulted in the advent of low-quality bikes. Low-quality bikes would be cheap and made with fewer quality materials. Using low-quality materials to make electronic bikes may result in the malfunctioning of the bike in a short time. 


 Quality materials, which are costly, will be used to make quality bikes, thus making the bike expensive. The frame of the bike, pedal, brake, motor, and battery combine together to give a wholesome bike. Manufacturers develop each part of the vehicle and try to give a better performing bike than the last one. 


 But there are also cheap companies trying to sell their products at a lower price by making them use cheaper materials. Some even try to sell it at a higher price though it is made of low-grade materials to portray as it a quality product. Using low-quality electric bikes has its consequences and will degenerate it.


Even when the electric bike is created using quality products, there are chances for your bike to malfunction. 


What does an electric bike’s controller do?

   The electric bike’s controller connects all the electric parts like the motor, battery, throttle, display, pedals and etc. It is the brain of the bike and manages all the functions of the bike. It is a small computer that enables the bike’s function like controlling the power of the motor, acceleration of the bike, etc.


Controllers come in a small protective box to protect from external heat and water that may damage and affect the overall performance of the bike. Some are designed to hold it outside the bike’s frame, and some design it to be hidden inside the frame of the electric bike. 


While assisting the functions of the electric bike, various controllers are also designed to provide different protection, they are:

  • Brake protection

Brakes in any vehicle enable to slow down or abruptly stop the vehicle. It is really an important part of any vehicle as it saves you from crashing and slamming. The controllers in the electric bikes give more priority to the brake than any other. 

  • Over temperature protection

Controllers know the limit of the transistors. The controller would shit down when the transistors reach their maximum safe heat level. This controller is really helpful when the controller is inside the frame of the bike.

  • Low voltage protection 

This might come in handy if the bike’s battery is discharging high voltage. This controller will monitor the battery’s discharges continuously, and when it reaches the limit, it shuts down. 

  • Over-voltage protection 

This protection would come in handy for people who often overcharge their electric bikes. As overcharging might damage the battery and weaken its lifespan, using this controller you can protect it. This controller would automatically stop the flow of electricity to the battery when the battery reaches its maximum charging level.

  • Over current protection 

The motor of the electric bike uses energy to control the bike. This controller allows the motor to consume the energy within the limit. This is useful if the motor consumes more energy from the battery.


Reasons for the heating of the electric bike’s controller

   A controller converts the electric energy into current, to control the motor.

   When the motor is functioning for a long time, it will heat up. This is normal, but if the controller working with the motor is heating up too soon, we should check and repair it if the need arises. 


There are many reasons for the controller to heat up, and here are a few of them:

  • Riding for a long time 

To ride an electric bike that’s working through its motor for a long time with high speed requires more power to generate it. This increases the heat of the controller.

  • The controller is made with low-quality materials

When buying an electric bike or any other vehicle, one should always contemplate the quality of the product as well as its parts. As quality products have a higher span of life than low-quality products, this factor decides the longevity of the vehicle. 

In the case of an electric bike, one should look at its battery, motor, and controller, as they are the main aspects of it. The controller generates the power to the motor to control the bike from the battery. The low-quality controller would heat up soon when transferring the energy.  

  • Overvolting

Overvolting an electric bike is using more power to increase the speed of the motor. When there is an increase in the use of the battery and the motor, it heats them up with the controller.

  • Overload

An electric bike is replacing traditional bicycles and other motor vehicles. We can use it to go on grocery shopping or commute, and many are using it for their shopping too. Though electric bikes aid to carry one’s things, one should know the limit and not overload them.

When there is a load on the bike,  or the person driving is overweight, to bear the weight and advance, it uses more power which increases the temperature.

  • Rough terrain and steep path

Climbing a steep path or riding on rough terrain requires low effort from the rider in an electric bike than in a traditional bike. Though it requires less effort from the rider, the motor’s work increases, thus heating up the motor and the controller.

  • Size differences 

If the controller’s power is higher than the motor’s intake, it would result in the malfunctioning of the motor due to excess power. And if the controller’s power is lower than the motor, the motor will be underpowered. This would result in the heating of the controller.

  • Damages in the controller

Controllers in the electric bike connect all the parts of the bike and assist in their function. If there is any damage to it, it might take more power to manage all the functions. When more power transfers in order to function, the control might heat up.

  • Breakdown of the cooling system

As the controllers in an electric bike aid in managing all its functions, the controllers would heat up soon. For this reason, they come with an inbuilt cooling system that reduces the heat and cools the controller thereby, it can function appropriately.


   Controllers are usually made using heat-insinuating materials as it is normal for the heat to rise up when using any electric devices. But the owner would know what the normal heat would rise to and if it rises higher in a shorter period. This will be the cue to repair or replace the controller.


Ways to cool down the controller 

   Even though rising of the temperature of the electric bike’s controller is normal, it should cool down before it reaches higher before damaging. One should know the grounds of the increasing temperature to attempt to cool it down and protect it. Follow these methods for a cool controller:

  • If the heightened temperature is due to riding the electric bike for too long at high speed, stop the bike. Switching off the motor and the controller would halt its function and let it cool down sometimes. Try to ride it after ten to fifteen minutes of cooling down or try pedal riding without the support of the motor.
  • If the controller is heating up due to the high power used by the motor to climb the steep path or to ride on rough terrain, try slowing down. Slowing down the electric bike can somewhat cool the motor and thus the controller. 
  • If you notice the increase in the temperature of the controller and deduce it is because of the weight it is carrying, get rid of some weight. This might reduce the work of the motor and allows the controller to cool a bit. 
  • Controllers may heat up if the materials used to make them are of low quality. If you happen to know that the rise in the temperature is due to a low-quality controller, try to replace it with a better controller. They are made out of heat-insinuating materials and it would reduce the heat and help to cool off. 
  • If you find that the high temperature of the bike’s controller is due to the usage of overvolt, try to decrease its use of it. 
  • If you notice the rising of the heat is due to the size differences between your controller and the motor, change one of them to the other’s correct voltage.
  • If you find any damages or faults in the controller, change the controller to a better capacity.
  • Change the cooling system of your electric bike, if the heating is due to its breakdown. 


Types of electric bike controllers

   Industrial Revolution brought in the use of iron and steel to create different shapes and build machines. This made human work easier and by the 20th century, microelectronics were introduced. 


 Though electric bikes were patented in the 19th century, only in the later part of the 20th century did they gain popularity. The main reason for this is the motor and controller are made using heavy and expensive materials and it was impossible to ride it with that weight. When microelectronics were introduced in the 20th century, batteries, motors, and power controllers were made using lighter-weight materials which were cheaper. 


 One can see numerous changes in the parts of the electric bike in two decades. But nothing much changes in the motors and the controllers of the bike, though many changes can be seen in the battery. 


There are three types of electric bike motors, they are:

  • Brushed DC Motor Controller

These controllers are mostly in use in scooters, electric bikes, and other light electric vehicles. They are simple and easy to use. Many DIY hobbyists and enthusiasts use it.

The brush in the motor pokes the commutator and pushes the motor to move.

These motor controller designs are more straightforward and it comes with a magnet connector to connect both the motor and the controller. The set of keys induced in it transfers the energy to the engine. 

  • Brushless DC Motor Controller

Most electric bikes use brushless DC motors and brushless DC controllers as they are efficient and reliable. Its service and operation are simple. It comes with a permanent magnet.

As there is no brush to boost the movement of the motor, you can steer the motor electronically using motor control systems.

  Though they look like brushed controllers, they come with three phases of the controller. Using a set of keys and at least two transistors, they can be controlled.

  • Brushless DC Motor Controllers with Hall Sensors.

Hall Effect Sensors are used to encourage the movement of the rotor according to the stator. The rotor is the rotating part of the motor, while the stator is the fixed part of the motor. The Hall Effect Sensors also determine other attributes like speed essential to the efficiency of the motor. 


Choosing an electric bike’s controller

   As electric bike controllers determine the efficiency of the motor and the performance of the whole bike, it is vital to know your controllers. If replacing or at least knowing the electric bike’s controllers, there are factors to consider, they are:

  • Voltage and Power

If you are trying to replace your controller, and you are going for the non-programmable controller, check the controller’s and motor’s voltage and power. 

The controller’s and motor’s voltage should be the same. The power of the controller and the motor should be the same or the controller’s power slightly more than the motor. 

If you are planning to purchase a programmable controller, you can adjust the power accordingly. The voltage of the motor and the battery should match the controllers. And this will ensure more stable function, controls the temperature, and reliable service.

  • Controller Current Rating

The controller’s current rating should be lower than the battery’s output current. 

  • Phase and Battery Current

Phase current and the battery current are both different things and many beginners confuse them. 

Phase current is attached to the motor and it can be higher than the better current. 

One should check the controller’s phase current and the motor current before choosing an electric bike. They should match or if the controller supplies more current than the motor’s capacity to intake current, it will heat up. 

The varnish coatings on the motor will deprive it property due to the excess heating of the motor and create a short circuit. 

  • Driving Type of the Controller

There are two types – Sine wave controller and Square wave controller, which differ in phase voltage waveform. 

The sine wave controller produces a sinusoidal waveform and it creates less noise. When riding uphill or carrying loads, it delivers an efficient ride and smoother ride on normal roads. Though, these controllers only work with matched motors and consume more energy, which will cost the owner more.

Square wave controllers produce rectangular waveforms and create a loud noise. They deliver less efficiently when riding uphill or carrying heavy loads, and not so smooth rides on normal roads. But these controllers can work with different types of motors, and efficient braking or acceleration. People would prefer this as this controller is affordable. 

  • Hall sensor or dual mode

The Hall sensor controller is a hall sensor or dual mode. Depending on the sensor signals, the controller regulates the voltage to the motor.