Greenworks 24V 12-inch string trimmer / edger review

REVIEW – A reliable string trimmer is an indispensable tool for yard work.  However, gas models are loud and create noxious fumes, and corded electric units are inconvenient. The Greenworks 24V 12-inch string trimmer with edger mode is a lightweight, feature-rich, battery-powered tool. I have one to review. Read on to see what I think!

What is it?

The Greenworks 24V 12-inch string trimmer with edger mode is a battery-powered string trimmer for yard work. In the United States, the string trimmer is also referred to as a weed whacker, weedwacker, or line trimmer.  The handle side of this unit has a small battery that is charged by an AC adapter and the cutting side has a small electric motor attached to a monofilament line. The motor housing may be tilted to make it easier to operate on steep hills or embankments. The motor housing may also be rotated 90 degrees to convert the string trimmer into an electric edger. The vertical edger can be used to create a distinct boundary between the lawn and another surface. The debris guard of the trimmer has an attached wheel that makes it easier to guide the trimmer along the ground to create boundaries with a paved, concreted, or asphalted area.

What’s in the box?

• String trimmer (disassembled)
• battery
• battery charger
• spare spool and spool cover
• instructions and warranty

Hardware specs

• Motor: 24V brushed
• No-load speed: 8000 rpm
• Cutting line diameter: 0.065″
• Cutting path diameter: 12″
• Feed type: auto feed
• Weight (without battery): 5.9 lbs
• Battery weight: 1 lb
• Storage and operation temperature: 32°F – 113°F
• Charging temperature: 32°F – 104°F

Design and features

Unboxing

The Greenworks 24V 12-inch string trimmer with edger mode comes in a plain cardboard box. The components are loosely packaged within the box.

Design

The Greenworks 24V 12-inch string trimmer with edger mode must be assembled before use. A screwdriver is required to install the trimmer guard but a much more important item is required before use: safety glasses. String trimmers, even with a plastic guard, can jettison sharp-edged debris at high velocity. This debris may be ricocheted off of nearby objects into the operator’s face.

Assembling the trimmer is relatively easy. The steps involved include attaching the guard, assembling the shaft, and attaching the auxiliary handle. The guard is attached with three Philips head screws. The trimmer guide, a steel loop that indicates the approximate full length of the wire, fits onto a channel above the guard.

The shaft is pre-wired from the handle and battery on one end to the motor on the other. The shaft is designed from aluminum and has an adjustable length. When using the trimmer the handle height adjusts from about 25″ to 32″ from the cutting height and when using the edger the handle height adjusts from about 28″ to 36″ from the guide wheel height. The auxiliary handle fits on the top of the adjustable shaft. The position is adjustable along the entire length of the shaft and is tightened to the shaft with a hand knob on the right side of the top handle.

The directions do not explicitly indicate that the protective paper should be removed from the line trimmer, but this step should be done to prevent the line from getting too long.

The spool will release about 0.4″ of line each time the machine is started. At first, I thought that this may be too much line released at a time, but based on the length of the line I have observed when using the trimmer, this is about right. Several times I needed to advance the line before starting the next trim. This is accomplished by starting the trimmer and then stopping it. The length of the cutting line is controlled by a centrifugal clutch that engages when the head is turning relatively slowly. You can see the clutch button here on the base of the rotating head.

In the pictures below you can see that the clutch button is released when the head is spinning slowly but as the head speeds up the clutch button sinks and prevents the spool from further advancement. each time this happens an audible click is heard. 

The trimmer comes with a spare spool and spool cover. Each spool is loaded with 14’6″ of filament. By the math, this corresponds to 420 startings of the trimmer. I figure with my use, I may start this about 40 times each week when I trim the walkways, dog pen, trees, pavement, and beds around the house. Even if I need to replace the spool every ten weeks this doesn’t seem like too much of a hassle. The filament may be replaced onto the spindle by tucking in about an inch of the filament into the center of the spindle and then winding in the direction indicated by “rewind →”.

The inch of filament is caught in the channel pictured below.

One design issue that I wish was more robust is that the tool is not protected from rain or water. the directions require that the vent holes for the motor be brushed off and that the unit be cleaned with a neutral detergent. I wish that the tool could be cleaned with a garden hose. 

The battery on the unit I received for evaluation is only designed to power tools but the battery on the unit sold by Amazon has a USB port on it too which allows the 2Ah battery to be used as a high capacity USB charger. The battery has a 3 LED energy level gauge. The gauge is not accessible or viewable when the battery is installed but installing and removing the battery is very easy. Additional batteries may be purchased for between $40 and $50 dollars.

Operation

The operation is very simple and as easy to use as a typical string trimmer. If you are used to a unit that requires bumping the head to advance the line, then this unit is a little different.

The line is advanced automatically each time the unit starts. To advance the line significantly start the unit momentarily, wait for it to come to a stop, then repeat until the desired line length is reached.

The length of the shaft is adjustable with a cam lever so it may be changed without additional tools.

The rotation of the head for edging and the angle of the head are easily changed with a press of a button.

Performance

The string trimmer works similarly to gas-powered trimmers I have used in the past, with the exception that it is lighter weight, quieter, less costly to operate, and doesn’t produce noxious exhaust. Like other trimmers, it works better if it is used to cut with the tip of the unit, and the cutting is from the right to the left so that the trimmer is cutting into the guard.

This video shows the trimmer at work around a tree.

The edger also works very well. It was easier for me to use the edger freehanded rather than relying on the wheel, but the performance was very good.

What I like

• useful
• quiet
• lightweight

What I’d change

• charge indicator
• ability to clean using water spray

Final thoughts

The Greenworks 24V 12-inch string trimmer with edger mode may cause some green thumbs to wonder if it is powerful enough or lasts long enough for their yard. While I cannot recommend this for commercial landscapers (the unit is not warranted for commercial use) I believe that many readers will be very happy with the Greenworks 24V 12-inch string trimmer’s performance and the quiet, pollution-free operation of its battery-powered motor.

Price: $69.99
Where to buy: Greenworks (Use coupon code GWSAS25 to save 25% (expires after 9/30/21)) and it’s also available on Amazon
Source: The sample of this product was provided by Greenworks.