Greenworks 40V 20″ Twin Blade Mower Review: Is This the Right Cordless Mower for Your Yard?

Choosing a lawn mower can feel surprisingly overwhelming. If you’ve been staring at the wall of options online, reading conflicting advice on forums, and wondering whether a cordless lawn mower can really replace a gas-powered one, you’re not alone. Thousands of homeowners face the exact same decision every spring — and the pressure to pick the right one is real. After all, this is a purchase you’ll live with (and mow with) for years.

Greenworks 40V 20" Push Mower with 4.0Ah & 2.0Ah

Home & Kitchen > Kitchen & Dining Features

amazon.com

9.5 /10

(6.9K reviews)

Out of Stock

$279.00

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Updated: July 31, 2026

Price as of Jul 31, 2026. We earn from qualifying purchases.

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If you are shopping around, our greenworks 60v 54 zero turn mower puts this pick in context. Our greenworks 60v 30 riding mower review walks through the details of stepping up to a riding model.

Key Specifications at a Glance

The package comes with both batteries and a charger, so you don’t need to buy anything extra to get started. That’s worth emphasizing because some competitors sell the mower body alone and require you to purchase batteries separately, which can add $100 or more to the total cost.

What Exactly Are You Getting?

At its core, this is a cordless, battery-powered push lawn mower made by Greenworks, a company well known for building electric outdoor tools. Here’s what each part of that means in plain terms:

• Cordless — There’s no power cord trailing behind you. You’re not tethered to an outlet. You move freely around your yard just like you would with a gas mower.
• Battery-powered — Instead of gasoline, this mower runs on rechargeable lithium-ion batteries. Think of these like the battery in your phone, but much larger and designed to power a motor that spins steel blades.
• Push mower — You walk behind it and push it manually. It doesn’t have a self-propelled feature (where the mower moves on its own and you just guide it). We’ll talk about what that means for your experience below.

Deep Dive: The Features That Matter

1. Dual Battery System with Auto Switch

One of the standout features is the auto-switch dual battery system. The mower has two battery slots. When the first battery runs out, the mower automatically switches to the second one — no stopping, no fumbling, no interruption. Imagine having two fuel tanks on a car that seamlessly switch when one runs empty.

This is a smart design choice that effectively doubles your mowing time without any effort on your part. With both batteries installed, you’re looking at a combined runtime that comfortably handles most small to medium yards in a single session — a genuine advantage over single-battery competitors in this price range, where you’d otherwise stop mid-mow and wait 60+ minutes for a recharge.

2. Twin Blade Design for a Better Cut

Most budget mowers use a single blade. This Greenworks model uses twin blades, and the difference matters. Two blades create more cutting passes per rotation, which means:

• A cleaner, more even cut across your lawn
• Superior mulching — grass clippings are chopped finer, so they decompose faster and feed your lawn naturally
• Better bagging performance — if you prefer to collect clippings, the finer pieces pack more efficiently into the bag

On that mulching point, the science backs it up: turfgrass specialists at land-grant university extension programs have long recommended leaving finely clipped grass clippings on the lawn, noting they can supply a meaningful portion of your lawn’s annual nitrogen needs and reduce fertilizer requirements. The twin-blade design makes “grasscycling” genuinely practical, because the clippings are small enough to filter down between the grass blades rather than sitting on top as unsightly clumps. For homeowners who care about the look and health of their lawn, this is a meaningful upgrade over single-blade designs at a similar price point.

3. Smart Cut Technology

Greenworks calls this “Smart Cut Technology,” and here’s what it does in simple terms: the mower automatically senses how thick or tough your grass is and adjusts its power accordingly. When it hits a dense patch, it ramps up. When the grass is lighter, it dials back to conserve battery.

Think of it like adaptive cruise control in a car — it adapts so you don’t have to think about it. This feature helps maximize both cut quality and battery life, which are usually at odds with each other. On thick, damp spring growth, you’ll hear the motor surge; on a light maintenance pass, it quietly sips power. The practical result is fewer mid-mow battery swaps and less stalling in heavy grass — a common complaint with fixed-power budget electrics.

4. Lightweight and Easy to Maneuver

Because there’s no gas engine, fuel tank, or heavy-duty steel housing, this mower weighs dramatically less than a comparable gas push mower — often by 30 to 40 pounds. That difference is immediately noticeable the first time you lift it out of the car trunk or pivot it around a garden bed. For smaller users, older homeowners, or anyone with a yard full of trees, flower beds, and tight corners, the lighter frame makes mowing significantly less fatiguing.

It also starts with the push of a button instead of a yank cord — no priming, no choke, no arm-wrenching pull starts. If you’ve ever fought with a stubborn gas mower on a cold morning, you’ll appreciate this every single week.

5. Low Maintenance, Low Noise, No Fumes

There are no oil changes, no spark plugs, no air filters, no fuel stabilizer, and no winter carburetor headaches. Maintenance essentially amounts to keeping the deck clean and sharpening the blades once or twice a season. It’s also far quieter than a gas mower — quiet enough that you can mow early in the morning or in the evening without annoying the whole neighborhood. And there are no exhaust fumes, which matters if you’re mowing near windows, patios, or play areas.

Pros and Cons

Who Should Buy This Mower?

The Greenworks 40V 20″ Twin Blade Mower is a great fit if you:

• Have a yard of ¼ acre up to ½ acre (or smaller) with mostly manageable grass
• Are switching from gas to electric and want an affordable, complete kit out of the box
• Value a clean, mulched cut and lawn health over raw cutting speed
• Want minimal maintenance and quiet, fume-free operation

You should probably look elsewhere if you have more than an acre, battle very thick or tall grass weekly, or specifically want self-propelled drive. In those cases, step up to a larger 60V or 80V model — our greenworks 60v 30 riding mower review