Greenworks 40V 21" Brushless Cordless Electric Lawn Mower Review: Specs, Pros and Cons

What stands out

• Brushless motor delivers higher torque and longer life
• 21-inch steel deck offers durability and efficient cutting
• 7-position single-lever height adjustment for varied terrain
• 3-in-1 capability: mulch, bag, or side discharge
• Includes 12-inch string trimmer with variable speed trigger

Who it fits

Key specs explained

Cutting Width: 21 in

This width covers a 21-inch swath per pass. You will need fewer passes to mow your lawn compared to narrower models. This size fits well in standard residential yards. It balances coverage speed with maneuverability around obstacles. Check your gate width to ensure the mower fits through entry points easily. Wider decks cover more ground but may be harder to store in tight sheds.

Runtime: Up to 45 min

The battery lasts up to 45 minutes on a full charge. This time depends on grass thickness and your speed. It is enough for medium-sized lawns. Thicker grass or higher cutting heights may reduce this time. You should plan your mowing route to finish within this window. Compare this duration with other 40V models to ensure it meets your yard size requirements.

Motor Type: Brushless

A brushless motor has no carbon brushes to wear out. This design provides more torque and runs quieter. It also lasts longer than brushed motors. You get efficient power delivery without frequent maintenance. This type of motor is standard in modern cordless mowers. It ensures consistent performance over many seasons. Look for this feature to guarantee long-term reliability and lower upkeep needs.

Deck Material: Steel

The deck is made from durable steel. This material resists dents and impacts from rocks or roots. It provides structural strength for the cutting blades. Steel decks are heavier than plastic but offer better longevity. You benefit from a robust build that withstands rough terrain. Compare this with polymer decks which are lighter but may crack. Steel is a practical choice for durability-focused buyers.

Battery Capacity: 5.0Ah

The 5.0Ah battery stores enough energy for extended use. Higher amp-hour ratings generally mean longer runtime. This capacity supports the 45-minute operation claim. You can use this battery with other Greenworks 40V tools. It offers flexibility if you own multiple devices. Check if the battery is included in the package. This spec indicates the power reserve available for your mowing tasks.

Steel Deck and Push Design

The deck is constructed from steel, which the listing highlights for its durability. This material choice suggests a robust build capable of withstanding impacts from hidden debris better than lighter plastic alternatives. The 21-inch cutting width defines the physical footprint of the mower as you push it across your lawn. You will need fewer passes to cover the same area compared to narrower models, which can save time on larger, open grassy spaces.

Height adjustment is managed via a single lever with seven positions. This layout allows you to change the cut height quickly without switching tools or reaching for complex mechanisms. The push drive type means you provide the momentum. There is no self-propulsion system to add weight or complexity, keeping the unit lighter and easier to maneuver around tight corners or garden obstacles.

Vertical storage is a key design feature. The listing states this saves 70% more space compared to traditional horizontal storage. This means you can store the mower in a garage corner or shed aisle without blocking access to other items. The finish and general build are described as maintenance-free, with no gas or oil systems to manage. This simplifies your workflow, allowing you to focus on mowing rather than engine care.

Setup and Daily Operation Guide

This model arrives as a push mower paired with a string trimmer. The listing includes a 5.0Ah battery and a charger. You must charge the battery fully before first use. The runtime is rated at up to 45 minutes, though this varies based on grass conditions and your technique. The mower relies on a 40V power source. You do not need gas, oil, or emissions checks. The brushless motor starts instantly, eliminating pull-cord efforts.

For mowing, you adjust the cutting height using a single lever. There are seven positions to choose from, allowing you to adapt to different lawn environments. The 21-inch steel deck offers durability. You can switch between rear bagging, side discharge, and mulching modes. This 3-in-1 design lets you handle clippings as needed. The push drive type means you walk behind the unit. You control the speed and direction manually.

The included 12-inch string trimmer features a .065-inch dual-line auto-feed head. You use a variable speed trigger to control cutting speed. This helps you maneuver around plants and shrubs precisely. For storage, the mower supports vertical positioning. This feature saves 70% more space compared to horizontal storage. The system is described as maintenance-free. You avoid routine mechanical servicing associated with gas engines. The quiet operation of the brushless motor reduces noise during daily tasks.

Before You Buy This Mower

Before you buy, check if your existing Greenworks 40V batteries are compatible. This mower requires a 40V power source. If you own other tools in this ecosystem, you can share batteries. The listing includes a 5.0Ah battery and charger. You may need additional batteries for larger yards. The 45-minute runtime varies by grass conditions. Consider buying extra batteries if your lawn exceeds this capacity. The steel deck requires occasional cleaning to prevent debris buildup. Keep the blade sharp for optimal mulching. This model is a push mower. It lacks self-propulsion. If your yard has slopes, consider a self-propelled alternative. The included string trimmer is a bonus. It uses a .065" dual line. You should purchase replacement lines. Vertical storage saves space. Fold the handle when not in use. This mower suits flat, standard residential lawns. It fits well alongside other cordless options if you value simplicity. Check the 21-inch cutting width against your gate sizes. Ensure your storage area accommodates the vertical fold. This practical choice works well for homeowners who prefer electric tools. It delivers reliable performance without gas maintenance.

Check before you buy

• Verify compatibility with existing Greenworks 40V batteries.
• Check if your yard size exceeds 45-minute runtime.
• Confirm gate width allows 21-inch mower passage.
• Ensure storage space fits vertical folded handle.

The product at a glance

1

Greenworks 40V 21" Push Mower and String Trimmer

Best for: Small to medium lawns with storage constraints

Power Source

Cordless battery

Cutting Width

21 in

Voltage

40V

Drive Type

Push

Battery Capacity

5.0Ah

Runtime

Up to 45 min

View on Amazon: Greenworks 40V 21" Push Mower and String Trimmer Affiliate link

This Greenworks 40V mower uses a brushless motor and a 21-inch steel deck to handle your lawn. It includes a 5.0Ah battery for up to 45 minutes of runtime. The single-lever height adjustment offers seven cutting positions. You get a 3-in-1 design for mulching, bagging, or side discharge. It also comes with a 12-inch string trimmer for edging tasks.

Pros

• Brushless motor provides more torque and longer life
• 21-inch steel deck offers durability
• Includes 5.0Ah battery for up to 45 minutes of runtime
• Vertical storage saves 70% more space
• Comes with a 12-inch string trimmer with variable speed trigger

Cons

• Push drive type requires manual effort
• Runtime varies based on grass conditions
• No self-propulsion mechanism listed

Good fit if

• You want a versatile tool that includes a string trimmer
• You need vertical storage to save space in your shed
• You prefer a durable steel deck over plastic

Skip if

• You have a large lawn requiring extended runtime beyond 45 minutes
• You want a self-propelled mower to reduce physical effort
• You prefer a lighter weight option without a trimmer attachment

Verdict: Greenworks 40V 21" Brushless Mower is a solid choice for homeowners who want a durable steel deck and the added utility of a string trimmer in one package. It suits those with small to medium lawns who value vertical storage and brushless motor efficiency.

Specifications side by side

Frequently asked questions

See also

• greenworks 40v 21 brushless cordless electric lawn mower alternatives
• best greenworks cordless lawn mowers
• greenworks 40v 21 self propelled lawn mower review
• greenworks 40v 12 in cordless review