I remember those Saturday mornings vividly. The sun would just be cresting the trees, the air still cool and fresh, and my tranquility would be shattered by the sputtering, roaring protest of my old gas mower. It was a ritual of frustration: the endless yanking of a stubborn pull-cord, the reek of gasoline on my hands, the constant trips to the gas station, and the ear-splitting noise that made me the least popular person on the block before 9 AM. Mowing the lawn felt less like a satisfying chore and more like wrestling with a cantankerous, fume-belching beast. I knew there had to be a modern solution—a way to reclaim the peace of my weekend mornings without sacrificing the power needed to keep my lawn looking pristine. This quest for a quieter, cleaner, and more convenient mowing experience is what led me to the world of high-powered battery mowers, and specifically, to the machine we’re examining today.
- 40V 21” LAWN MOWER - Get more done, faster, with Greenworks electric lawn mowers. This 40V self-propelled lawn mower provides up to 45 minutes of run-time with fully charged 5.0Ah battery (varies...
- BRUSHLESS MOTOR / DURABLE STEEL DECK - This electric mower features a durable 21" deck, and a highly efficient brushless motor that provides more torque, quiet operation, and longer life
- SINGLE LEVER HEIGHT ADJUST - 7 position height adjustment provides the best cut in all environments. 3-in-1 design offers rear bag, side discharge, and mulching capabilities
What to Consider Before Buying a Walk-Behind Lawn Mower
A walk-behind lawn mower is more than just an item; it’s a key solution for maintaining the health and beauty of your property. It’s the difference between a chaotic, overgrown yard and a manicured, inviting outdoor space. The primary benefit of a quality mower is its ability to provide a consistent, clean cut that promotes healthy grass growth, prevents pests, and boosts your home’s curb appeal. The right mower transforms a dreaded task into an efficient, and sometimes even enjoyable, process. Neglecting this crucial piece of equipment can lead to an unmanageable lawn that requires costly professional intervention, harbors weeds and pests, and detracts from your home’s value.
The ideal customer for a modern battery-powered model like this is someone with a small to medium-sized lawn (typically under half an acre) who values convenience, quiet operation, and low maintenance. If you’re tired of storing gasoline, performing oil changes, and struggling with pull-starts, this category is designed for you. However, it might not be suitable for those with exceptionally large properties (an acre or more), as battery runtime can become a limiting factor. Likewise, if your property consists of extremely dense, tough, or frequently overgrown brush, the raw, unrelenting torque of a high-end gas mower might still be a better fit. For those with very small, flat lawns, a manual reel mower could be a simpler, more eco-friendly alternative.
Before investing, consider these crucial points in detail:
- Dimensions & Space: Consider the cutting width, or “deck size.” A wider deck (like the 21-inch one on this Greenworks model) means fewer passes to mow your lawn, saving you time and energy. Also, think about storage. One of the standout features of many new battery mowers is the ability to store them vertically, which can save up to 70% of the floor space a traditional mower would occupy in your garage or shed.
- Capacity/Performance: For battery mowers, this is all about the voltage (V) and amp-hours (Ah). Voltage is a rough measure of power, while amp-hours indicate the battery’s capacity, which translates to runtime. A 40V system is a great middle-ground, offering ample power for most residential lawns. The included 5.0Ah battery is substantial, but as we’ll discuss, factors like grass thickness and self-propulsion usage can dramatically affect the actual minutes of use you’ll get.
- Materials & Durability: The mower deck material is a critical component for longevity. Alloy steel decks, like the one found on the Greenworks 40V mower, are the standard for durability and impact resistance, far superior to cheaper plastic decks. Also, inspect the wheels and handle assembly; you want sturdy components that can withstand years of bumps, turns, and seasonal use.
- Ease of Use & Maintenance: This is where battery power truly shines. Look for features like a push-button start, single-lever height adjustment, and tool-free handle adjustments. The biggest long-term benefit is the near-elimination of maintenance. There’s no gas to stabilize, no oil to change, no spark plugs to replace, and no air filters to clean. The only regular maintenance is cleaning the underdeck and sharpening the blade.
Keeping these factors in mind, the Greenworks 40V 21″ Self-Propelled Lawn Mower 5.0Ah stands out in several areas, particularly in its user-friendly design and maintenance-free operation. You can explore its detailed specifications here.
While the Greenworks 40V 21″ Self-Propelled Lawn Mower 5.0Ah is an excellent choice, it’s always wise to see how it stacks up against the competition. For a broader look at all the top models, we highly recommend checking out our complete, in-depth guide:
- Effortless Power for ½ Acre Yards- Experience gas-like performance without the hassle—35 minutes of continuous runtime from a single 4.0Ah battery (full charge in 2 hours). Perfect for small to...
- POWERED BY A RELIABLE B&S ENGINE: Equipped with a powerful 140cc B&S engine, known for its smooth start-up, consistent performance, and long-term durability—ideal for tough mowing jobs.
- Powerful & Easy-Start Gas Engine: Get going quickly with the reliable 144cc 4-stroke OHV engine on this gas lawn mower. Features a convenient primer button for simplified cold starts, delivering...
First Impressions: Smart Design and Near-Instant Assembly
Unboxing the Greenworks 40V 21″ Self-Propelled Lawn Mower 5.0Ah was a refreshingly simple affair. The main unit comes almost fully assembled in the box. The process was intuitive: unfold the handle, lock the two clamps into place, and you’re done. There were no tools, no confusing diagrams, no bolts and nuts to fumble with—a stark contrast to the assembly required for some gas mowers. This confirms the experience of many users who praise its out-of-the-box readiness. However, a word of caution is warranted. Some users have reported receiving units with loose parts or cosmetic scratches, suggesting that handling during shipping can be rough. We recommend a quick inspection upon arrival.
The first thing I noticed was the mower’s substantial feel. The alloy steel deck gives it a reassuring heft and a sense of durability. It doesn’t feel like a toy. It’s important to note a common point of confusion: the product specs list the item weight around 22 pounds, but this is wildly inaccurate. As one user discovered, the shipping weight is over 80 pounds. The mower itself, once unboxed, feels closer to 60-65 pounds. It’s maneuverable, but not featherlight. The controls are well-placed, with a simple push-button start and a bail bar to engage the blades, plus a separate bar for the self-propel feature. The single-lever height adjustment is a dream, clicking solidly into one of seven positions. My initial impression was of a well-thought-out machine designed for user convenience from the ground up.
Key Benefits
- Extremely quiet operation compared to gas mowers
- Push-button start for effortless, reliable ignition
- No gas, oil, or regular engine maintenance required
- Vertical storage capability saves significant garage space
- Part of a large 75+ tool 40V compatible battery system
Potential Drawbacks
- Battery runtime is highly variable and often less than advertised
- Self-propel feature dramatically reduces battery life
- May struggle with very tall, thick, or wet grass
A Deep Dive into the Greenworks 40V Mower’s Real-World Performance
After the initial setup, it was time to see how the Greenworks 40V 21″ Self-Propelled Lawn Mower 5.0Ah handled the challenges of a real lawn. We tested it over several weeks on a quarter-acre suburban lot with a mix of flat areas, a slight incline, and sections of both thick Kentucky bluegrass and finer fescue. We evaluated its core functions: cutting power, battery endurance, and the effectiveness of its self-propelled system and ergonomics.
Brushless Motor Power and Cut Quality
The heart of this mower is its brushless motor. Unlike older brushed motors, brushless technology is more efficient, runs cooler, produces more torque, and has a significantly longer lifespan. When I pressed the start button and engaged the blade, the difference was immediate. Instead of a deafening roar, there was a high-powered whir. It’s quiet enough to hold a conversation over, a benefit that cannot be overstated.
On the lawn, the 21-inch steel blade spun up to speed quickly and delivered an impressively clean and even cut on dry, moderately-grown grass. The single-lever height adjustment is fantastic, allowing me to easily raise the deck for a first pass on a thicker section and then lower it for a finishing cut. The 3-in-1 capability (mulch, bag, side-discharge) is a premium feature that offers great versatility. We found the mulching function worked very well, finely chopping clippings and returning them to the lawn without leaving clumps. The bagger is also generously sized and easy to attach and remove. However, the mower’s limits become apparent when faced with challenging conditions. As one user with dense Kentucky grass noted, you need to stay on top of new growth. If you let the lawn get too long or try to mow right after a heavy rain, the motor can get bogged down and the mower may stall. It has plenty of power for routine maintenance, but it’s not a brush hog for reclaiming an overgrown field.
The Elephant in the Room: Battery Life and the 40V Ecosystem
This is arguably the most important—and most debated—aspect of the Greenworks 40V 21″ Self-Propelled Lawn Mower 5.0Ah. Greenworks advertises up to 45 minutes of runtime on the included 5.0Ah battery. In our testing, this number is… optimistic. It’s achievable only under ideal conditions: a flat, dry lawn with sparse grass, using the mower on a high cutting setting without the self-propel feature engaged.
The moment you introduce real-world variables, that number drops. On our quarter-acre lot with thick grass, we consistently got around 30-35 minutes of runtime without using the self-propel. This was just enough to finish the job. However, once we engaged the self-propelled drive, the runtime plummeted to about 20-25 minutes. This is a critical point that many user reviews confirm. One user stated, “Using the self propelled function cuts your battery life in half,” and our experience validates this completely. Another was “shocked” when the battery died before they could even finish their flat backyard. This isn’t a defect; it’s the physics of electric power. Powering both the blade and the wheels is a significant energy draw.
Our expert advice is unequivocal: if your lawn is larger than a quarter-acre or has any significant slopes where you’ll need the self-propel feature, you should consider the cost of a second battery as part of the mower’s total price. Having a second battery on the charger while you work eliminates any runtime anxiety. The silver lining is the 40V ecosystem. This single battery powers over 75 other Greenworks tools, from string trimmers and leaf blowers to chainsaws, adding immense value if you plan to invest in a suite of cordless yard tools.
Self-Propelled Drive, Ergonomics, and Storage
The rear-wheel self-propelled system provides excellent traction, especially when heading up our test incline. It pulled the mower along at a comfortable walking pace, significantly reducing the physical effort required. Unlike a push mower, where you provide all the forward momentum, here you simply guide the machine. This is a game-changer for anyone with hills or a larger yard.
However, we did notice what some users have mentioned: the drive engagement can feel a bit abrupt. It’s not a deal-breaker, but it takes a moment to get used to the immediate pull. Ergonomically, the padded handle is comfortable to grip, and its adjustability accommodates users of different heights. But the true standout feature in this category is the vertical storage. By simply releasing the handle clamps, you can fold the handle forward and stand the mower up on its end. In our garage, this reduced its footprint from a large rectangle to a small, manageable square, freeing up valuable floor space. This is a brilliant piece of engineering that owners of smaller garages will deeply appreciate, as confirmed by a user who called the feature “a blessing.”
A Note on Safety and Build Quality
The overall build feels solid, centered around that sturdy steel deck. But it’s crucial to address a harrowing safety issue raised by one user. They reported that upon inserting the battery while standing in front of the mower, it immediately lurched forward and ran them over. This sounds like a terrifying malfunction, potentially of the self-propel engagement lever. This serves as a critical safety reminder for all self-propelled mowers: ALWAYS stand behind the mower handle when inserting the battery and safety key. Never place yourself in the machine’s path when it’s being powered on. While this appears to be a rare and extreme quality control failure, it underscores the importance of proper operating procedure. The vast majority of users have no such issues, but safety must always be the first priority.
What Other Users Are Saying
After analyzing dozens of user reports, a clear consensus emerges that mirrors our own findings. On the positive side, users overwhelmingly love the convenience. One owner celebrated her newfound independence, stating, “I don’t have to ask Husband to help do anything I can start and store myself. Easy to use.” The quiet operation and lack of fumes are universally praised. Many, like one user with a 5,000 sq ft lawn, find the battery life perfectly adequate for their needs, especially when mulching and not using the self-propel feature.
The negative feedback centers almost exclusively on battery life. The gap between the advertised 45 minutes and the real-world 20-30 minutes (especially with self-propel) is a frequent source of frustration. The common refrain, as one person put it, is “Definitely need more than 1 battery.” There are also scattered reports of quality control issues, such as units arriving with scratches, loose parts, or being dead on arrival. While not widespread, it suggests that quality checks could be more consistent. These issues, combined with the battery limitations, are the primary reasons this mower doesn’t receive universal five-star ratings, despite its many excellent qualities.
How Does It Compare to the Alternatives?
The Greenworks 40V 21″ Self-Propelled Lawn Mower 5.0Ah occupies a popular spot in the market, but it’s far from the only option. Depending on your needs, lawn size, and budget, one of these alternatives might be a better fit.
1. Greenworks 40V Push Lawn Mower Blower String Trimmer Combo
- 40V CORDLESS MOWER - This 40V Brushless lawn mower provides the power you need with up to 45 minutes of runtime on a fully charged 4.0Ah battery. The battery completely charges in 120 minutes.
- 40V CORDLESS TRIMMER / EDGER (2-IN-1) - This 40V String trimmer Converts from trimmer to edger with push of a button;Trimmer head rotates 90° so you can trim and edge at multiple angles;Push button...
- 40V CORDLESS BLOWER - This 40V Blower delivers 350 CFM and 100 MPH for powerful leaf and debris clean up,with Two Speed Switch (High/Low)
If you’re just starting your cordless tool collection and have a smaller, flatter lawn, this combo kit from Greenworks offers incredible value. The trade-off is a smaller 16-inch cutting deck and the lack of a self-propelled drive, meaning you’ll be providing the push power. However, for a small yard, this is often more than sufficient. The huge advantage is that for a similar price to our reviewed mower alone, you also get a capable leaf blower and string trimmer, plus two batteries (4.0Ah and 2.0Ah) to kickstart your collection. This is the ideal choice for budget-conscious buyers with modest lawn care needs.
2. Fiskars 18″ Manual Reel Mower
- ECO-FRIENDLY PUSH LAWNMOWER: Manual reel lawn mower with 18" cut width; No gas, oil, charging, or cords required; 60% easier to push than other reel mowers and ideal for regular lawn maintenance
- BEST-IN-CLASS CUTTING PERFORMANCE: InertiaDrive Reel boasts twice the cutting power of standard reel mowers, while the StaySharp Cutting System eliminates the cost and inconvenience of manual blade...
- SUPERIOR ERGONOMICS: Reversible grass chute can direct clippings away from your feet, making it easier to mow tough patches while limiting messiness; One-touch handle height adjustment enhances your...
For the ultimate in eco-friendly, quiet, and simple lawn maintenance, a manual reel mower is unbeatable. The Fiskars model is a modern take on a classic design, featuring advanced mechanics that make it easier to push than older reel mowers. There’s no battery to charge, no motor to fail, and the only sound is a satisfying “snip-snip” as the blades shear the grass. This is an excellent choice for very small, flat yards (less than 1,500 sq ft) and for homeowners who enjoy the physical activity of yard work. It’s completely maintenance-free aside from blade sharpening and provides a uniquely precise, scissor-like cut that is very healthy for the grass.
3. Scotts 2000-20S 20-Inch Push Reel Lawn Mower
- Classic Scotts 20 inch push no-motor manual reel rotary lawn mower features 20" cutting width, 5-blade ball bearing reel, and 10" dual tracking wheels
- Quick-snap 1"-3" cutting height adjustment for a clean, even cut every time with this Scotts classic hand push reel rotary 20 inch lawn mower
- Blades on the Scotts classic hand push reel rotary 20 inch lawn mower are made of quality, heat-treated alloy steel for staying sharp longer
Similar to the Fiskars, the Scotts Classic Push Reel Mower is another top-tier manual option. Its key advantage is a wider 20-inch cutting path, which reduces the number of passes required compared to the 18-inch Fiskars. It boasts five heat-treated steel blades for a clean cut and offers a good range of height adjustments. Choosing between the Scotts and the Fiskars often comes down to brand preference and specific deals available. The Scotts is a fantastic choice for those who want the benefits of a manual mower but have a slightly larger “small lawn” where the extra two inches of cutting width will make a noticeable difference over a season.
Our Final Verdict: Is the Greenworks 40V Mower Right for You?
After extensive testing and analysis, our verdict on the Greenworks 40V 21″ Self-Propelled Lawn Mower 5.0Ah is clear: it is an excellent machine for the right user. If you have a small to medium-sized lawn (up to a half-acre), value convenience and quiet operation, and are ready to leave the hassles of gas power behind, this mower is a top contender. Its push-button start, single-lever adjustments, versatile 3-in-1 functions, and brilliant vertical storage design make it a pleasure to use.
However, you must go into the purchase with realistic expectations about battery life. The self-propelled feature is a fantastic labor-saver, but it comes at a significant cost to runtime. For any lawn approaching a half-acre or with significant slopes, we strongly recommend budgeting for a second 5.0Ah battery from the outset. For those with tiny lawns, a manual reel mower might be a better fit, and for those with sprawling properties, a gas mower or a higher-voltage battery system may still be necessary. But for the vast majority of suburban homeowners, this Greenworks mower hits a sweet spot of power, performance, and unmatched convenience.
If you’ve decided the Greenworks 40V 21″ Self-Propelled Lawn Mower 5.0Ah is the right fit, you can check its current price and availability right here.
Last update on 2025-10-22 / Affiliate links / Images from Amazon Product Advertising API