Greenworks 40V 21″ Self-Propelled Cordless Lawn Mower review

Have we ever wished our lawn could look freshly cut without the noise, fumes, and hassle of a gas mower?

Why We Chose the Greenworks 40V 21″ Self-Propelled Cordless Lawn Mower

We wanted a mower that could handle real-world yards without the gas headaches—no pull cords, no oil changes, no fuel spills. The Greenworks 40V 21″ Self-Propelled Cordless Lawn Mower with a brushless motor and 5.0Ah battery promised exactly that: strong performance, cordless convenience, and compatibility with a whole ecosystem of tools.

We also liked that this mower is designed for people who want pro-level results with less effort. Between the self-propelled drive, 4-in-1 cutting options, and LED headlights, it is clearly built for regular, weekly use rather than just occasional trimming.

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Key Features at a Glance

We find it helpful to get an overview before we go deeper, especially with a feature-rich tool like this one. Here is a quick breakdown of what this mower offers and what that means for everyday mowing.

Feature	What It Is	Why It Matters to Us
40V Brushless Motor	High-efficiency, no-brush electric motor	More power, longer life, quieter than gas
21″ Steel Deck	Durable, full-width cutting deck	Fewer passes, more robust than plastic decks
Self-Propelled Rear-Wheel Drive	Motor-assisted movement with adjustable speed	Less pushing effort, better control on slopes
5.0Ah 40V Battery	High-capacity lithium-ion battery	Longer runtime per charge
Fast Charger Included	Dedicated charger for the 40V battery	Less downtime between mows
4-in-1 Mowing System	Mulching, bagging, side discharge, turbo leaf pickup	Flexible for different yard conditions and seasons
LED Headlights	Front-mounted LED lighting	Mow earlier in the morning or later at night
75+ Tool Compatible	Part of the Greenworks 40V family	One battery platform for many tools
3-Year Tool Warranty	Manufacturer warranty on the mower	Extra peace of mind on longevity
3-Year Battery Warranty	Warranty specifically for the battery	Protection against battery issues

We liked having everything included in one package: mower, battery, fast charger, grass bag, and multi-function cutting system. That way, we are not stuck buying add-ons just to make basic use of the mower.

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Design and Build Quality

We care a lot about how a mower feels and holds up over time, not just how it looks on paper. With this Greenworks model, the design aims for durability and usability.

The 21-inch steel deck instantly sets it apart from some lightweight plastic-deck competitors. Steel adds weight but also gives more stability and durability when bumping into roots, edging along borders, or catching a stray stick in the yard.

Materials and Construction

We appreciate that the deck is made of steel rather than lighter composites, which can sometimes flex or feel flimsy. The overall chassis feels solid, and the wheels are sturdy enough for regular suburban use.

The handle design includes foldable or collapsible points, making storage in tight garages or sheds much easier. We find that especially helpful if we are already storing other Greenworks tools on the same wall or shelf system.

The finish and fit of the parts feel well put together. We do not get the sense that it is a budget throwaway mower; instead, it feels like a long-term yard partner.

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Brushless Motor Performance

The brushless motor is the heart of this mower, and for us, this is where cordless really stands apart from older electric tools. A brushless motor uses electronics instead of physical contact brushes, which cuts down on friction, heat, and wear.

Power and Torque in Real Use

We notice that, compared to some cheaper cordless mowers, this Greenworks model does not bog down as quickly in thicker grass. The torque output is strong enough to handle weekly cuts on average suburban lawns and even some neglected areas, as long as we do not push it brutally fast through tall, wet grass.

The 21-inch cutting path helps us cover more ground in fewer passes. Combined with the brushless motor, we get a sense of steady, consistent power rather than that “straining” feel we often get with smaller, lower-voltage electrics.

Efficiency and Runtime

Because the motor is brushless, it uses battery power more efficiently. That means:

• Less wasted energy in the form of heat
• Better runtime per charge
• Longer motor life over time

We notice that the mower maintains blade speed fairly well as the battery drains, rather than dropping off sharply at the end of a charge. That makes for more uniform cuts, even near the end of our mowing session.

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Self-Propelled Rear-Wheel Drive and Variable Speed

Self-propelled functionality is a major selling point for us, especially if we are dealing with larger yards or any kind of slope. Instead of pushing all the weight ourselves, we simply guide the mower while it does most of the moving.

How the Self-Propelled System Feels

The rear-wheel drive gives us better traction than front-wheel drive, particularly when we are pushing uphill or working over uneven areas. We simply engage the self-propel function and walk behind it.

We also like that the speed is variable. Some mowers are either too slow or too fast for our preferred pace, but here we can adjust it according to how quickly we want to move and how thick the grass is. Slower speeds help in tall or dense grass to maintain cutting quality.

Maneuverability on Different Terrain

We find the mower manageable on both flat lawns and modest slopes. Because the rear wheels do the driving, they grip softer areas better than front-drive systems that can lose traction when the front lifts a bit.

However, as with any self-propelled mower, we still have to steer around obstacles, trees, and flowerbeds. The added weight of the steel deck and drive system is noticeable when we are pulling the mower backward manually, but that is fairly typical for this class of self-propelled cordless mower.

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21″ Steel Deck and Cutting Width

A 21-inch deck hits a sweet spot for many of us. It is wide enough for a decent mowing pace yet still narrow enough to maneuver around landscaping features.

Coverage and Cutting Efficiency

With a 21″ cutting width, we get fewer passes than with a smaller 18″ or 19″ deck. That directly translates into shorter mowing time, especially on medium to large lawns. Every extra inch of cutting width matters over the course of an entire yard.

The steel deck gives a stable base for the blade, which helps create a more even cut. If we care about uniform lawn appearance, that stability tends to give better results than a flexy plastic deck.

Height Adjustment

While the product summary does not spell out the exact range of cutting height positions, Greenworks typically offers multiple height settings on similar models. We can expect to adjust cutting height with a single lever controlling all wheels.

That allows us to set a higher cut for hot summer months (to protect the grass) and a lower cut for cooler seasons, or for that final mow before winter.

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4-in-1 Mowing System: Mulch, Bag, Side Discharge, and Turbo Leaf Pickup

We love having options for how our clippings are handled. Lawns can change a lot through the year, and so can our preferences. This mower’s 4-in-1 system gives us the freedom to shift approaches quickly.

Mulching Mode

Mulching is where the mower chops clippings repeatedly into fine pieces and drops them back into the lawn. We often prefer this mode for regular weekly mowing, because:

• It returns nutrients and moisture to the soil
• It reduces the need for chemical fertilizers
• It keeps clippings off sidewalks and driveways

We simply attach the mulching plug or remove the bag, ensuring the mower is set to recirculate clippings under the deck.

Bagging Mode

Bagging is still the best choice when:

• The grass is overgrown
• We are mowing after a long wet spell
• We want a super clean, “no clippings anywhere” look

The included grass bag collects clippings, and we can empty it into our yard waste bin or compost pile. While bagging can mean more trips to dump clippings, it leaves a very tidy finish, which we especially appreciate when guests are coming or when we are doing a first cut on a neglected yard.

Side Discharge Mode

Side discharge is the more traditional style where clippings are ejected out of a chute on the side. This is handy when we are tackling tall grass or do not care about visible clippings.

We tend to use side discharge if we are doing a rough cut on an area that has not been maintained regularly. It helps keep the deck from clogging in heavy conditions while still getting the job done.

Turbo Leaf Pickup

The turbo leaf pickup is a nice bonus for shoulder seasons. In autumn or in yards with trees, we can use this mode to pull leaves off the grass instead of raking everything manually.

We like that the mower’s airflow and suction can help gather leaves into the bag, making fall cleanups more efficient and less backbreaking.

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LED Headlights for Early or Late Mowing

The integrated LED headlight feature may sound like a small touch, but we have found it surprisingly useful. Many of us have full schedules, and mowing often happens at dawn or dusk when light is less than ideal.

Mowing at Convenient Times

With bright LEDs on the front, we can:

• Start earlier in the morning, before the sun is high
• Finish mowing later in the evening after work
• See obstacles, toys, and edges more clearly in low light

Because the mower is electric and much quieter than gas, we are less likely to disturb neighbors, especially combined with the lower operating noise.

Safety and Visibility

The lights help us see where we are going, but they also make us more visible in our yard if others are around. Whether we are near sidewalks or simply working while family members are outside, being more visible is always a plus.

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Battery and Charger: Runtime and Convenience

The included 5.0Ah 40V battery and fast charger are central to the mowing experience. If the battery is too small or slow to recharge, even the best mower design can be frustrating. This kit aims to avoid that.

5.0Ah Capacity and Typical Runtime

A 5.0Ah battery is on the higher-capacity side for a 40V system. While exact runtime will vary based on grass height, thickness, mowing speed, and use of self-propel, we can generally expect one full charge to handle many small to medium-sized lawns in a single session.

We find that if we mow regularly (not letting grass get too tall), runtime is more than adequate for a typical suburban yard. On larger properties, we might consider adding a second 40V battery to minimize downtime.

Fast Charger and Charge Times

The fast charger helps reduce the time between uses. We can often go from a drained battery to a full charge in a fraction of the time older chargers require.

This matters when:

• We have a larger yard that might need two charge cycles
• We want to use the same battery in multiple tools in a single day
• We forget to charge and need a quicker turnaround

Knowing we have a fast charger included right out of the box saves us an extra purchase and keeps our workflow smoother.

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Noise Level and Neighborhood Friendliness

One of the biggest perks of going cordless is dramatically reduced noise. Gas mowers are notoriously loud, often piercing through closed windows and disrupting anyone nearby.

3x Quieter Than Gas

We appreciate that this mower is advertised as roughly three times quieter than typical gas models. While we still hear blade noise and motor sound, it is more of a hum than a roar.

That has practical benefits:

• We can mow earlier or later without feeling rude
• We reduce noise stress for ourselves and our families
• We create a more peaceful outdoor environment overall

If we have ever worn ear protection just to cut the grass, this quieter operation feels like a real upgrade.

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Greenworks 40V Ecosystem Compatibility (75+ Tools)

One of the strongest advantages of this mower is that the battery is compatible with more than 75 other Greenworks 40V tools. Lawn care rarely stops at mowing; we often need trimmers, blowers, chainsaws, and more.

Expanding Our Tool Set

Instead of buying different batteries and chargers for each tool, we can:

• Use the same 40V battery in a string trimmer
• Swap it into a leaf blower for quick cleanup
• Power a hedge trimmer, chainsaw, or other yard tools

This shared platform saves money and simplifies storage. We deal with fewer chargers, fewer cords, and a more organized charging station.

Long-Term Investment Value

We like viewing this mower not as a standalone item but as an entry point into a complete cordless system. Over time, as we add more tools, the overall cost per battery goes down, and we get more value out of the original purchase.

For those of us planning to transition fully away from gas-powered tools, this compatibility is a key factor.

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Ease of Use: Starting, Handling, and Storage

We care not just about performance but also about how simple the mower is day-to-day. If something is a hassle to deal with, we end up dreading the job.

Starting and Controls

Compared to pull-start gas engines, this mower feels effortless. We typically:

1. Insert a charged battery
2. Engage safety features (such as a safety key or handle lever)
3. Press or turn the start control

The mower comes to life without yanking a cord or fiddling with choke settings. That is especially nice for anyone with shoulder or arm issues or for those of us who simply want a smoother experience.

The controls for self-propel speed and blade operation are straightforward and within reach on the handle. Once we get used to the layout, operating the mower becomes very natural.

Handling and Weight

Because of the steel deck and self-propel system, this is not the lightest mower on the market. However, the self-propel feature compensates by doing much of the pushing for us while moving forward.

We need a bit more effort when maneuvering in tight spaces or pulling the mower backward, which is common to most self-propelled designs. On open lawns, though, it glides smoothly.

Folding and Storage

The handle design typically allows folding or collapsing the mower down to a more compact profile. That makes it easier to:

• Store against a wall in the garage
• Fit into tight shed spaces
• Transport in a vehicle if needed

We like that we do not need a dedicated large corner of the garage just for one tool.

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Cut Quality and Lawn Appearance

At the end of the day, all the features in the world do not matter if the lawn does not look good. A mower’s cut quality is our most visible metric of success.

Consistency Across the Lawn

We find that the combination of brushless motor, 21″ steel deck, and sharp blade produces a consistent, even cut when we operate at a reasonable walking pace. Uneven cutting typically happens if we rush or if the grass is extremely tall and heavy.

For best results, we prefer:

• Regular weekly mowing
• Avoiding very wet grass when possible
• Using the right cutting height for the season

Under those conditions, the mower leaves a neat, professional-looking finish that meets most residential expectations easily.

Handling Longer or Denser Grass

When we encounter overgrown grass, we usually:

• Raise the cutting height for the first pass
• Move more slowly to reduce motor strain
• Consider using side discharge rather than mulching

By doing that, the mower is capable of taming tougher areas, though it may take an extra pass to get everything perfectly level.

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Maintenance and Care

One of our favorite aspects of cordless electric mowers is how low-maintenance they are compared to gas models. We do not have to worry about spark plugs, fuel filters, or oil changes.

Routine Maintenance Tasks

Typical ongoing care includes:

• Cleaning the deck periodically to remove built-up clippings
• Checking the blade for sharpness and wear
• Keeping the battery contacts free of debris
• Storing the battery indoors during extreme heat or cold

We also occasionally check wheel adjustment mechanisms and handle bolts to make sure everything stays tight and secure.

Blade Sharpening and Replacement

For the best cut quality, we like to sharpen or replace the blade as needed. A dull blade tears grass instead of slicing it, which can make the lawn look ragged and increase disease risk.

Replacing the blade is generally straightforward with basic tools, as long as we follow safety precautions and always remove the battery before working under the deck.

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Warranty and Support

Having solid warranty coverage reassures us we are not taking on unnecessary risk. This mower includes:

• 3-year warranty on the tool
• 3-year warranty on the battery

That level of coverage signals that the manufacturer is confident in the product’s durability. We appreciate that the battery itself has a dedicated warranty, since batteries can be among the most expensive components to replace.

If any issues come up within the warranty period, we have a clear path for repair or replacement rather than being on our own.

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Pros and Cons Summary

To keep things honest and balanced, we like to lay out the strengths and potential drawbacks side by side. That helps us decide if this mower fits our needs and preferences.

What We Appreciate

• Powerful 40V brushless motor that handles typical residential lawns well
• 21″ steel deck for durability and fewer passes across the yard
• Self-propelled rear-wheel drive with variable speed for easier mowing on slopes and larger yards
• 4-in-1 cutting options: mulching, bagging, side discharge, and turbo leaf pickup
• LED headlights that support early morning and late evening mowing
• Quieter operation compared to gas, making it more neighborhood-friendly
• 5.0Ah battery and fast charger included, ready to use out of the box
• Compatibility with 75+ Greenworks 40V tools, building a coherent cordless ecosystem
• 3-year tool and 3-year battery warranties offering strong protection

Where We See Potential Trade-Offs

• Heavier than some compact corded or non-self-propelled mowers, due to the steel deck and drive system
• Runtime limited by a single 5.0Ah battery for very large yards, possibly requiring a second battery
• Best performance when mowing regularly; very tall, wet grass can still challenge any cordless mower
• More complex mechanism than a simple push mower, which may mean slightly more to learn at first

None of these are deal-breakers for us, but they are important to keep in mind when matching the mower to our specific yard size and conditions.

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Who This Mower Is Best For

We find that this Greenworks 40V 21″ Self-Propelled Cordless Lawn Mower fits certain users particularly well.

Ideal Users and Yard Types

We think this mower is especially well-suited for:

• Homeowners with small to medium or moderately large lawns who want cordless freedom
• People with mild to moderate slopes who appreciate self-propel assistance
• Anyone tired of gas fumes, noise, and engine maintenance
• Users planning to build a full cordless yard tool set within the Greenworks 40V platform

We see it as a strong choice for homeowners who mow regularly and care about lawn appearance but do not want the hassle and noise of gas engines.

When It Might Not Be the Perfect Fit

If we have:

• Very large acreage requiring multiple hours of continuous mowing
• Extremely rough, brush-like terrain beyond typical lawn care
• A tight budget where a basic corded mower is the only option

Then we might need to weigh whether multiple batteries or a larger commercial solution is more appropriate. For most suburban and many semi-rural lawns, though, this mower will meet needs very well.

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Practical Tips for Getting the Most from This Mower

We like to go beyond specs and share a few habits that help us get the best long-term experience.

Mowing Habits

• Mow regularly: Keeping grass at a manageable height improves cut quality and saves battery.
• Avoid very wet conditions: While the mower can function in damp grass, extremely wet lawns can clog the deck and strain the motor.
• Use the right mode: Mulch for weekly maintenance, bag in overgrowth or for a perfectly clean look, and use turbo leaf pickup in fall.

Battery Habits

• Store batteries indoors during temperature extremes, rather than leaving them in a shed that bakes in the sun or freezes overnight.
• Avoid completely draining batteries whenever possible; recharging before they are totally empty can prolong life.
• Keep battery contacts clean and dry for the best power delivery.

These small steps help us maximize both performance and longevity.

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Final Thoughts: Is the Greenworks 40V 21″ Self-Propelled Mower Worth It?

We see this mower as a strong, well-rounded cordless solution that successfully replaces gas for many residential users. The combination of a 40V brushless motor, 21″ steel deck, self-propelled rear-wheel drive, and 4-in-1 cutting options gives us real power and flexibility, not just convenience.

We appreciate the quieter operation, the LED headlights, and the inclusion of a 5.0Ah battery with a fast charger. Tying everything into a larger ecosystem of 75+ compatible tools adds long-term value, especially if we want a whole garage of cordless equipment running on the same platform.

If our goal is to maintain a neat, healthy lawn without gas fumes, oil changes, and loud engines, this mower is a compelling choice. It supports efficient, regular mowing with less effort, and it does so while fitting into a broader cordless lifestyle that many of us are moving toward.

For homeowners looking to step into or expand within the Greenworks 40V lineup, the Greenworks 40V 21″ Self-Propelled Cordless Lawn Mower with Brushless Motor and 5.0Ah Battery is, in our view, a capable, friendly, and future-ready partner for yard care.

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