48SPM21 48V/24V 21" Dual-Volt Self-Propelled Lawn Mower

with Battery and Charger


The Greenworks 48SPM21 48V/24V 21" Dual-Volt Self-Propelled Lawn Mower is a cordless, self-propelled lawn mower powered by either a 48-volt or 24-volt lithium-ion battery. Some of its features and specifications include:

  1. 21-inch steel deck for a wide cutting swath
  2. 3-in-1 cutting capability: side discharge, rear bag, and mulching
  3. Single lever cutting height adjustment
  4. Self-propelled feature for ease of use
  5. Adjustable handle for comfort
  6. Large capacity grass collection bag
  7. Compatible with both 48-volt and 24-volt Greenworks lithium-ion batteries
  8. The product dimension is 63.5 x 23.5 x 39 inches (L x W x H) and weight is 84.5 pounds.

- Brushless Motor: Provides power, longer runtimes, quiet operations and extends the life of the motor- 3-In-1 Design: side-discharge, mulch, or collect the clippings in the 14.5-gallon grass collector for quick and easy disposal- Self-Propelled Rear Wheel Drive with speed control at your fingertips for less strain and easy maneuverability- Dual-Volt Technology - Kitted to include 4Ah Dual Voltage battery for reliable power that integrates your yard and power tools into one versatile platform for all your yard, garage, and home tool needs- Replacement Battery: BAM-704 - Replacement Charger: CAM803 - 3 Year Tool Warranty, 3 Year Battery Warranty

Frequently Asked Questions


What maintenance is required for my Greenworks mower?

Greenworks mower units require much less maintenance than a traditional gas unit. However, It will still require routine seasonal maintenance. After each use, we advise you empty the bag (if bagging has been used), then check/clean off debris on the side discharge and rear slot, clean the underside of the deck with a cloth, and wipe the unit down. If there is harder debris stuck to the underside, you may want to use a rubber deck scraper. Make sure to check the unit for loose nuts and bolts after use and secure them if needed. Do not expose this unit to water. Check the blade for any damage/dullness and replace or sharpen as needed. Store the unit in a cool, covered, and dry location such as garage or shed. If you have a battery-operated tool, batteries and chargers should be stored indoors. Please refer to your manual for more guidance on mower/battery maintenance and storage.

When should I cut my grass?

Here are some mowing tips that may be helpful: • Mow when grass is dry. • Mow no more than 1/3 of the length of grass at a time. • Mow in the morning or late afternoon to reduce the heat stress on the newly cut grass. • Alternate mowing patterns each time you mow. As grass develops a grain based on your cutting direction it will lean towards the direction of your mowing path. Changing the pattern allows better vertical growth and helps to keep the cut neater. • Consider mulching. To mulch, remove the bag and insert the mulch plug into the rear of the unit. This will leave the clippings on the lawn allowing the nutrients and nitrogen contained within them to return to the soil and allow the remaining grass to recycle them (always discharge the mulch towards a previously cut area to prevent your mower from bogging down). • Leave grass a little higher in shaded areas. This keeps them healthy in relatively nutrient poor conditions. • Always keep in mind what conditions your variety of grass prefers. If your grass prefers cooler climates, reduce the frequency with which you mow and increase the cutting height of your mower during hot seasons to compensate for the reduced growth rate these varieties may experience in this type of weather.

Do I always need to use my self-propelled feature when operating a self-propelled mower?

No, you don't have to engage the self-propelled feature to operate a self-propelled unit as there are two separate motors. Familiarize yourself with the self-propelled feature and the cutting feature of your unit (instructions are inside the manual). Once you understand these two features, you can engage the blade without using the self-propelled feature.

Can my Greenworks mower cut up pine cones, branches, twigs and other yard debris laying on my lawn?

Greenworks mowers are designed for grass, weeds and foliage. It's not advisable to depend on the mower to mulch any other types of debris. Before operation, please thoroughly inspect the area where the mower is to be used. Remove all stones, sticks, wire, toys, and other objects that could be tripped over or thrown by the blade. Thrown objects can cause serious personal injury.

Can I use my mower in wet conditions such as rain?

For safety reasons (which can be found inside your owner's manual under safety information), we advise not using the mower in wet conditions as unstable footing could cause operators to slip, causing a potential hazard. *The 60V X-RANGE line which features IPX4 weather-resistant construction can be safely used in damp conditions. Be mindful of your footing during use in potentially slippery conditions.*

What does SmartCut™ mean?

The SmartCut™ feature is designed to maximize run time and battery life by automatically detecting the length of grass and adjusting its power or throttle for the optimal cut. With this feature, the rotational speed of the blades will vary. For example, the blades will automatically spin faster when you hit thicker grass.

Does my Greenworks mower unit require gas or oil?

No! Gas and oil are not required to operate our units. Greenworks mowers emit zero emissions and are either battery operated or corded.

Is the battery from my Greenworks mower interchangeable with the other units?

Each voltage line has its own set of interchangeable tools and batteries but are not interchangeable across different voltage lines. For example, 24V batteries are only interchangeable with 24V tools, 40V batteries are only interchangeable with 40V tools, etc. To see compatible tools within each voltage line, select shop by voltage on the Greenworks site or follow the link: If you’re still unsure if your unit is compatible, please contact us at [email protected] for further assistance. We’re happy to help!

How do I start my mower unit?

Make sure you are starting the unit in the following order, or it will not start: 1. Push down and hold the safety switch button. While pressing the safety switch button with one hand, use your other hand to simultaneously pull the bale switch towards you. 2. Once the machine turns on, you can let go of the safety button and continue to hold the bale (lever) handle. The unit will only start when the safety button is pressed first, followed by the bale switch. If it is reversed, the unit will not power on. For some of our EZ Fold™ units the start sequence will not affect the unit. Use the correct batteries according to the unit and ensure the batteries have adequate charge. You can either push the button first or pull up the handle—these models are not affected by the start order. For corded units, ensure you have the correct extension cord (reference the owner’s manual) and power from your outlet. If you’re using a battery unit, ensure the battery has a full/adequate charge. However, please always refer to your owner’s manual for verification on the starting process as this would be the most accurate source of information.

Can I use a different Greenworks Amp hour (Ah) battery in my unit?

Yes! For most of our current units, as long as the batteries are from the same Greenworks voltage line (24V batteries with 24V tools, 40V batteries with a 40V tools, etc.), the amp hours (Ah) are interchangeable. Please refer to the below link for our voltage line: If you are unsure if your battery is part of a voltage line that can be interchanged, please contact us at [email protected] for further assistance. *Exceptions for our Greenworks 60v 8.0Ah and certain chainsaws in the 80v line.*

What does brushless mean?

A brushless unit has a brushless motor. While conventional motors have carbon brushes which tend to wear over time, brushless motors use magnents instead. This allows the motor to have a longer life, produce less heat, provide more torque, and use less battery. Basically, a brushless motor is a more powerful and efficient upgrade to the traditional brushed motor.

Does battery temperature matter?

Yes! The temperature of the battery should not be too warm or too cold. If the battery is too cold or too warm it may not be operatable—that's why it's important to let your battery reach room temperature prior to use. To avoid battery temperature issues, batteries should be stored indoors in a dry and cool location. More information on battery storage and temperature can be found in inside your owner’s manual.

Why isn’t my mower turning on?

Corded mowers: Make sure you are using the correct size extension cord by following the guide inside the owner’s manual. Check that the extension cord is not loose when inserted into the mower’s plug and ensure a secure connection to a live 120V AC, 60 HZ AC receptacle. Battery operated mowers: Check to ensure the battery capacity has an adequate or full charge, then secure the battery into place. If the battery is loose or can easily be removed, it doesn't have a complete and secure connection. Follow the starting guide located in your owner’s manual for further instruction.

Why does my mower cut grassy unevenly?

Your yard may be too rough or uneven. For a better cut, try moving the cutting height to a higher position when mowing on uneven surfaces.

Why isn’t my mulching working?

First, make sure the mulching plug is inserted into the rear slot at the back of the unit. Next, remove the bag. If too many grass clippings are sticking to the underside of the deck when mowing, the grass is too wet. Wait until the grass dries before mowing again. Also, it's important to keep the underside of the deck clean and clear of debris so that the blade can efficiently cut and mulch.

How do I stop my mower from vibrating?

Slight vibration is normal. However, if you notice an increase or difference in the vibration of the unit during use there may be an issue with the blade or motor shaft. If it’s an issue with the blade, simply replace the worn blade. However, if the motor shaft is damaged or bent you'll need to bring it into a service center. Please contact us at 1-888-909-6757 for further assistance.

Why is my mower hard to push?

Here are some reasons why your unit may be hard to push: • The cutting height is set too low for how tall the grass is—move the cutting height up. • The rear bag is full and is dragging on the ground. Empty the grass bag so it doesn't drag and add weight as you’re mowing. • The underside of the deck is caked with debris. Clean and clear it so the blade can work more effectively. General mower care for best results: • Prior to storage, clean and examine the machine for any damages. • Store the unit in a dry, covered, and cool location like a garage or shed. • Ensure that the unit is stored in a secure location that is not accessible to children or any other persons who should not be operating such machinery.

Can I use my Greenworks mower on hills and slopes?

Yes, though walk behind mower units should not be operated on slopes greater than 15 degrees. This is not a limitation of the unit, but rather to ensure safe footing for the user. When mowing on a hill remember to mow across rather than up and down.


Cut Depth:1.75 inchTool Warranty:3 YearsBattery Capacity:-

$ 499.99 
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