Perhaps you are in the market for a new lawn mower. You’ve probably heard about brushed and brushless motors. I know that purchasing a power tool is an investment of your hard-earned money. You want to make the best choice. The array of available options may leave you wondering, what is a brushless lawn mower?
- More Power Efficient
- Higher Motor Power Output
- Quieter Performance
- Low Friction Unlikely to Overheat
- Virtually No Service or Maintenance
What Is a Brushless Lawn Mower
A brushless mower is a relatively recent technology that gives you several advantages over other types of mowers. All lawn mowers are powered by either a gas engine or an electric motor. Two types of electric motors are brushed and brushless. Some specific design differences make a brushless mower more efficient and quieter than its counterparts.
To help you understand the differences, I’ll explain the basics of electric motor function and highlight the advantages and disadvantages of each type of lawn mower.
Brushless Motor Basics Explained
Both electric motor types function on the principles of attraction and repulsion between permanent magnets and copper coils. The key difference is the configuration. Keep in mind that contact between moving parts makes heat and friction as well as drains efficiency.
In a brushed motor, the coils rotate inside stationary magnets. Brushed motors are driven when DC voltage moves across the brushes, passes current through the windings, and make the motor spin. Contact between the brushes and coil causes wear on both parts. The coil is spinning, so contact causes friction and excess heat.
Since the contact conducts electrical current, it is impossible to lubricate either component. You must replace the brushes regularly to keep the motor functioning.
Brushless motors are a newer technology in which the permanent magnet rotates in the center surrounded by a coil made of copper wire windings. Electronic controls rotate the magnetic field instead of a mechanical commutator and brushes. This configuration does not create mechanical friction or excess heat and noise like a brushed motor.
Advantages of Brushless Lawn Mowers
Brushless mowers are gaining popularity because their more sophisticated design offers several advantages over other mowers. They give you greater power efficiency and higher output. They are also quieter and require less maintenance over the machine’s life. There are several advantages to using brushless lawn mowers, including:
- More power efficiency
- Higher motor power output
- Quieter performance
- Low friction unlikely to overheat
- Virtually no service or maintenance
More Power Efficient
Mechanical friction in a brushed mower means loss of energy and efficiency. A brushless mower doesn’t lose energy from friction, so the battery power lasts longer. This means a higher percentage of fuel power converts to more rotational energy to drive the mower. You can expect an electric mower battery to last between 30 and 60 minutes on one charge. A more efficient mower gets closer to that 60 minutes mark, though mowers will vary by brand.
Brushless motors also control their energy use more efficiently. The electronic sensors monitor how hard the mower works, so it optimizes its output not to waste any energy.
Higher Motor Power Output
The construction of a brushless motor allows for higher power output. Most have three phases which indicate the number of windings around the magnet. A three-phase brushless motor has three groups of windings. Most mower motors have the standard three phases. Since the coils are outside the magnet, you can add windings to increase torque.
Another way brushless motors accomplish higher performance is to pass current through all three phases simultaneously. Usually, one phase is connected to the ground, one is open, and the third supplies voltage. This configuration can cause torque ripple as the phases switch jobs abruptly. Generating current through all three phases minimizes torque ripple and lowers the noise level.
As much as everyone tries to be conscious of their neighbors, you have to mow the lawn sometime. The threshold for harmful noise exposure is 85 decibels. Gas mowers can produce up to 95 decibels of sound, which is why you’ll see many professional lawn care crews wearing ear protection.
Electric mowers produce between 50 and 75 decibels. It’s difficult to find research that distinguishes different types of electric mowers. However, we know that brushes add to the noise produced by brushed mowers.
A brushless mower will not disturb your neighbors when you cut your lawn. Why? A brushed mower creates more noise when the brushes contact the coils. Since a brushless mower does not have these components to make mechanical friction, it is the quietest lawn mower.
Low Friction Unlikely to Overheat
All motors produce heat, but there is far less with a brushless motor than with a brushed one. Brushless lawn mowers do not produce mechanical friction and generate less heat overall.
Second, the coils are on the outside edge of a brushless motor. The design allows for heat to dissipate more efficiently. That allows a brushless mower to cool down more quickly after use.
A machine less likely to overheat and break down is more efficient and costs less to maintain over time.
Virtually No Service or Maintenance
As I mentioned before, brushed motors experience wear and tear on the brushes where they contact the commutator. You’ll have to replace the brushes to keep the motor running optimally. Eventually, the commutator also wears down so much that the motor no longer functions.
A brushless motor requires virtually no maintenance. One drawback is the difficulty you will experience servicing a brushless mower because of its more complicated electrical wiring.
While brushless mowers may have a higher initial cost, you’ll save money in the long run with lower maintenance costs. Brushed mowers are also more prone to overheating and breakdowns. A brushless mower can last about 5 to 10 times longer than a brushed motor.
Brushless Vs. Brushed Motor Vs. Engine
A third possible option exists when choosing a lawn mower. Instead of an electric-powered mower, you could choose one with a gas-powered engine. There are some trade-offs between greater power efficiency and overall maintenance costs. Some of these include:
- Power efficiency
- Cost difference
I’ve mentioned several aspects of brushless motor design compared to brushed motors. Another advantage to brushless motors is efficiency. You want to use as much of the torque the motor is generating as possible. A brushless mower can operate at 80-90% efficiency compared to the 60-75% of a brushed mower. You’ll get more work done faster with a brushless mower than with a brushed one.
A typical gas-powered mower will last longer on a large job than either type of eclectic mower. You can cut up to 14,000 square feet of lawn on a single tank of gas. You might consider a mower with an engine if you have a large lawn.
I’ve covered a few aspects of maintenance for both electric mowers. A brushless mower requires much less servicing than a brushed mower.
A gas-powered mower requires more maintenance than both. Like other engines, gas-powered mowers need spark plugs, air filters, fuel stabilizers, and oil changes. If you don’t use your mower over a long winter season, you must drain the gas tank and properly winterize the engine. You also have to buy gasoline regularly.
Cost is certainly an important consideration when choosing a lawn mower. Remember to consider upkeep and the initial cost of purchasing each machine. Each type of mower has its advantages and drawbacks.
The least expensive mowers are brushed motor electric mowers. They have the lowest initial cost, with some maintenance over their lifespan. These mowers last about ten years with proper maintenance. The battery experiences decreased capacity over time. Expect to replace the battery after five years.
A brushless mower is next in line in the cost comparison. You’ll pay a little more at the checkout counter for a brushless mower than a brushed mower. Although, as the technology becomes more widely used and efficient, the cost is already dropping. You’ll spend less on maintenance over its lifetime, and it will last a little longer than a brushed mower.
Gas Engine Mowers
A gas-powered mower is the most expensive to purchase and maintain. These mowers are more expensive initially and have several parts that need regular upkeep in addition to gasoline costs. Having a large property to maintain may make it a more practical choice.
Verdict: What Is a Brushless Lawn Mower
A brushless mower is a newer technology that allows for a quieter, more efficient electric lawn mowing experience. The cost is comparable to a brushed mower in terms of the overall expense. It is much less expensive and easier to maintain than a gas engine mower.
FAQs Brushless Lawn Mower
Here is one of the most frequently asked questions regarding brushless lawn mowers.