What is a Brushless Lawn Mower?

What is a Brushless Lawn Mower

Mowing the lawn is one of those simple pleasures in life where you get to be alone with your thoughts in nature, doing your best to keep a clean, attractive yard. As relaxing as this picture is, the reality is the loud thrum of the engine breaks through that peace and solitary enjoyment. Gas-powered mower motors are loud and create pollution, making them what many lawn owners consider a necessary evil.

Que the new age of battery-power compatible,  electric motors and cordless mowers, culminating in the introduction of the fully electric brushless lawn mower. Cordless lawn mower technology has gotten better and better, and a brushless mower gives you peace and the power to tackle any lawn-cutting height with less stress and expense.

As magical as it sounds, electric push mowers and other brushless mower models can be explained simply; read on to learn more. 

How Does an Electric Mower’s Motor Work?

All power tools have an engine, and nowadays, those engines run on electricity more and petroleum fuel less and less. While brushless motor technology is more efficient and makes better use of stationary magnets and rotational energy, the timing and sensors are more complex than in a standard motor. Once you understand the components of a brushless motor, you will be able to confidently use and maintain your cordless lawn mower.

A brushless mower has a permanent magnet that rotates at the center of the mower and 4 coiled wires that conduct the electric field. The spinning magnet sends electrical signals to the coils through external wiring and sensors that power the motor. Each of the four sections of the copper coil is powered when the smart controller senses the rotating magnet is in the correct position, and a high surge of energy powers the cordless lawn mower without any voltage dips. 

Inside the motor, the exchange is frictionless and results in increased efficiency and reduced noise and maintenance costs, which is why most times, brushless lawnmowers are a good choice. With faster chargers and extended battery life, most modern electric mowers can compete with gas mowers in average-sized lawns. Having a spare battery hooked up to a charger while you are mowing can allow you to tackle even the largest lawn without overheating or needing to make a gas run. 

EGO Power+ LM2101 21-Inch 56-Volt Lithium-ion Cordless Lawn Mower 5.0Ah Battery and Rapid Charger Included

Brushless vs Brushed Mowers

If you didn’t even know there were different kinds of electric and mechanical motors, you are not the only one. Inside a mower, you can find either a brushless or brushed motor. One uses friction to transfer electricity from the magnet to the motor the other uses external wires and sensors to rely on the current. Both of these types of machines have different benefits and drawbacks. Below is a breakdown of the differences between brushless and brushed mowers in electric lawn equipment. 

EngineAdvantageDisadvantage
Brushless MotorQuieter, more fuel-efficient More complicated and expensive to build 
Brushed MotorCheaper and wide availability Needs regular maintenance, voltage dips, and is more likely to overheat

Brushless Mower 

Brushless lawnmowers come in a wide range of models and types with different power capabilities. Using these mowers has many great benefits that make them the ideal lawn machines for most yard owners. In some cases, a brushless mower may not perform as well as it should, and the drawbacks might make it unsuitable for your yard.

Find out below.

Pros

The most noticeable advantage of electric lawn mowers with a brushless motor is that they require far less maintenance and last years longer than their brushed-powered counterparts. The external position of the copper coils allows for more frequent and longer windings that increase the electromagnetic field, which translates to greater torque and a cleaner cutting blade.

With frictionless energy transfers, there are no sparks, and scorching or overheating will not occur inside the motor. With well-designed electric sensors, the motor has adaptive power that allows for torque to increase and decrease depending on the height and density of the turf being cut. 

Cons

All of those amazing features above do not come cheaply. The initial cost of fully electric lawnmowers is higher than a brushed machine, but not many times over. A low-end electric mower will cost the same as a higher-end brushed machine, but that is before adding a spare battery or any other additions. Even though electric push mowers are virtually silent, they will still vibrate at low speeds. This isn’t really much of an issue but should be considered.

A major concern with electric battery mowers is that if something goes wrong with the controller or motor, the repairs are more difficult to make and usually more costly. For the highest transfer of energy, electric devices run on DC directly, but battery-powered lawnmowers need inverters to avoid electrical issues.

Brushed Mower 

A brushed motor is the main engine for gas-powered mowers and commercial landscape mowers. While they require more maintenance and costly fuel, they are easy to repair in the field and can handle the demanding toll commercial work puts on machines.

The main difference with conventional gas lawnmowers is that the copper coil is inside of the rotating magnet, and the energy exchange is through the friction of brushes. Because the brushes are springloaded conductors that come into contact with a commutator as it revolves, it creates friction and equipment ware. This also results in energy lost as heat and the smaller winding of copper coils offer less overall power generation.

Pros 

It costs much less to buy a conventional mower with a brushed motor than to purchase a cordless battery walk-behind push mower. A brushless motor is great and all but not if you can’t afford it, making brushed mowers better if your budget is very limited. If something goes wrong and you need to replace or repair engine components, you will spend far less on a brushed motor.

The electrical components of a brushless motor are much more costly than mechanical brushes and spools of copper. If you have an electric mower with a brushed motor, it can connect directly to DC power supplies for faster charging and higher energy efficiency. 

Cons

Brushes wear down and need to be replaced regularly, making it costly and time-consuming to keep brushed models tuned up. Brushes transfer energy through contact, and the resulting friction can cause sparks and possible scorching of internal parts.

As the friction builds, so does the engine heat. When a mower that is running hot meets thick turf or steep terrain, it may overheat and cut off. Not only is this bad for the engine, but it results in damaged turf, which becomes more susceptible to heat and disease. Brushed electric motors may experience a dip in voltage when moving into heavy grass that is not present when using a brushless motor. 

Is a Brushless Mower Worth the Extra Cost?

Greenworks 2 x 24V (48V) 20" Brushless Cordless Push Lawn Mower, (2) 4.0Ah USB Batteries (USB Hub) and Dual Port Rapid Charger Included

As technology gets better and the electric motor battery gets cheaper expensive mowers will get even more affordable without sacrificing power efficiency. Currently, there are still applications where brushed mowers may make sense, but as time goes on, that will be less and less the case. For now, let’s look at all the areas where brushless mowers outperform conventional motors. 

Efficiency

As mentioned earlier, the friction from the brushes causes energy to be lost as heat and not converted into power. Brushed mowers operate at around 60% to 70% efficiency, losing quite a bit of power. Conversely, high-end brushless mowers can boast a percentage of 80 to 90% energy efficiency. That 15 to 20% of extra energy is directed into power which creates less tedious work for you and more assistance from the mower. 

Cost 

While a brushless motored lawnmower is more expensive than a brushed gas engine mower, that is constantly becoming less of a reality. Some areas are introducing rebates for electric lawn equipment, and others are imposing fines for gas-driven machines. In just a few more years, our favorite brushless mowers should be easily affordable. 

Maintenance

Taking apart, tuning up, and replacing damaged components all fall under the realm of machine maintenance. Ideally, we would spend as little time as possible doing this, which is what makes brushless electric mowers so wonderful. Brushless motors break far less and last much longer than brushed motors.

If your brushless motor does malfunction, however, you will need more specialized service when things go wrong. These special services and specialty parts can break the bank and make buying a newer model a cheaper solution. 

On the flip side, every couple of months, you will want to check out the inner workings of your brushed motor to make sure all the contact points are still intact.  Brushed motors break down more often but can be repaired and tuned up much easier.

Replacing brushes every year or so can keep your mower in good shape without needing to constantly buy new mowers. The total life of a brushless motor will be much longer than a brushed mower, so, in the end, the few extra expenses for fully-electric motors come down over the course of the machine’s usefulness.