What Is ELI5 What's brushed and brushless motors ? And what's the difference between the two?!
Last updated: April 1, 2026
Key Facts
- Brushed motors use carbon brushes that maintain electrical contact with the rotating commutator
- Brushless motors use electronic controllers to manage the magnetic field switching
- Brushless motors have no brushes, so they produce less noise and heat
- Brushed motors require regular maintenance due to brush wear
- Brushless motors are more efficient, converting 85-90% of electrical energy to motion
How Brushed Motors Work
A brushed motor contains a rotating coil of wire (called an armature) positioned between the poles of a permanent magnet. When electricity flows through the coil, it creates a magnetic field that interacts with the permanent magnet, causing the coil to rotate. The key component that makes this work is the commutator, a split ring attached to the rotating shaft. As the armature spins, the commutator rotates with it.
Carbon brushes are small conductive blocks that press against the commutator as it rotates. These brushes maintain electrical contact with the commutator, delivering electrical current to the right parts of the coil at exactly the right time. Every half rotation, the brushes switch which segment of the commutator they contact, which reverses the current direction and keeps the motor spinning in the same direction. This is a clever mechanical switching system that requires no electronics.
How Brushless Motors Work
Brushless motors completely eliminate the carbon brushes and mechanical commutator. Instead, they use an electronic controller (called an ESC, or electronic speed controller) that switches electrical current to different coils at precisely the right moments. A position sensor detects where the permanent magnet is located and sends this information to the controller. The controller uses this feedback to know exactly when to switch current to the next coil, creating a rotating magnetic field that pulls the magnet around.
This electronic switching approach is much more efficient than mechanical brushes because there is no friction from brushes rubbing against the commutator. The motor runs smoother, cooler, and quieter as a result. Modern brushless motors can be found in everything from drone motors to electric vehicles.
Key Differences
- Efficiency: Brushless motors convert 85-90% of electrical energy into motion, while brushed motors convert about 75-80%. This higher efficiency means less wasted energy and less heat.
- Durability: Brushless motors last much longer because there are no brushes wearing down. They can run for 20,000+ hours, while brushed motors typically need maintenance after a few thousand hours of use.
- Noise and Temperature: Brushless motors run much quieter and cooler because the electronic switching eliminates brush friction.
- Cost: Brushed motors are cheaper to manufacture because they are simpler. Brushless motors require an electronic controller, which adds cost.
- Control: Brushless motors offer better speed and torque control through the electronic controller, while brushed motors have more limited control options.
Practical Applications
Brushed motors remain popular in consumer applications where cost matters, such as toy motors, inexpensive power tools, electric shavers, and small appliances. Brushless motors have become the standard in modern high-performance applications like power drills, impact drivers, e-bikes, drones, electric vehicles, and computer cooling fans. As battery-powered tools and devices continue to evolve, brushless motors are increasingly becoming standard, even in consumer-grade tools, because their superior efficiency extends battery life and improves performance.
| Feature | Brushed Motors | Brushless Motors |
|---|---|---|
| Efficiency | 75-80% | 85-90% |
| Lifespan | 2,000-3,000 hours | 20,000+ hours |
| Maintenance | Requires brush replacement | Minimal maintenance needed |
| Noise Level | Higher noise | Very quiet operation |
| Operating Temperature | Runs hot | Runs cool |
| Cost | Inexpensive | More expensive |
| Control | Simple control | Advanced electronic control |
| Common Uses | Toys, basic power tools | Drones, e-bikes, modern power tools |
Related Questions
What is a commutator in an electric motor?
A commutator is a split ring attached to the rotating shaft of a brushed motor that reverses the direction of electrical current every half rotation. This mechanical switching keeps the motor spinning in the same direction. The carbon brushes maintain electrical contact with the commutator as it spins.
Why are brushless motors more efficient than brushed motors?
Brushless motors are more efficient because they eliminate the friction from carbon brushes rubbing against the commutator. This friction wastes energy as heat in brushed motors. Additionally, brushless motors can be electronically optimized for better performance, while brushed motors have inherent mechanical limitations.
Can you convert a brushed motor to brushless?
While you cannot convert an existing brushed motor to brushless, you can replace it with a brushless motor of similar size and power rating. Modern brushless motors are often cheaper than they used to be, making replacement practical in most applications. You would also need to add an electronic speed controller to run the brushless motor.
Sources
- Wikipedia - Electric Motor CC-BY-SA-4.0
- Wikipedia - Brushless DC Electric Motor CC-BY-SA-4.0