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Greenworks 40V Cordless String Trimmer: Pros and Cons From an Owner

We've got quite a large property with a long driveway. A Greenworks trimmer gets quite a workout where we live so I do go through them.

Greenworks 14-inch 40V cordless string trimmer, model number 21362.

Greenworks 14-inch 40V cordless string trimmer, model number 21362.

My First Impressions of the Greenworks 40V Cordless Trimmer

My Greenworks battery-powered weed eater got here a few weeks ago. I checked the box the weed eater came in and all accessories to make sure nothing was damaged or missing. Pleased to say: all good.

Why I'm Switching to Lithium Battery Power

In case you're wondering why I'm converting all my tools to battery power, it's because we have about an acre of land and it requires a lot of maintenance, as you can imagine. Also, I got so tired of pulling away at the darn cord and keeping the thing running.

Up until a year ago, I've had a variety of gas-powered tools because I considered battery power not man enough for the job. But that seems to have changed now with battery power equaling and if not bettering gas power with backyard tools.

My Personal Review of the Greenworks Trimmer Features

Here is my personal review of the main features of the trimmer.

1. Assembly and Weight

Assembly was rather easy, as all one needed to do was put on the weed guard and also the handle.

Before that, I placed the 40V 4Ah battery on charge. I have a 40V 2Ah battery charger from the Greenworks 12-inch power saw I bought a year ago. It took about an hour from dead flat to full charge.

I took it outdoors as well as to the front of the house and looked dubiously at the growth of high weeds that were standing around 2 feet high. They had actually not been weed-whacked from mid last season, as I dislike weed consuming with a passion. All the vibration from gas-powered weed eaters really injures the shoulder, and so it had become a job for another day.

The first thing I noticed that this Greenworks is HEAVY. Note that no shoulder band came with my Greenworks device.

2. The Power

The weeds were there giggling and laughing at me with my new battery-operated weed eater showing no fear. The weeds took notice, and I think I saw them start to tremble a little. As for me, I was smiling like a maniac working from the top down.

3. The Bump Head

When it came time that I needed more line, I whispered a little prayer. No bump head I have actually ever used before has worked. None. That constantly required me to use a third-event head that you put cut line into. I did a light tap on the ground and, divine cow, it worked! I was satisfied!

4. The Vibration

It is nowhere near as bad as a gas-powered system. My shoulder, arms, and also hands, said "thank you" an awful lot!

5. The Balance

I had no problem with the balance of the Greenworks system. I am 5' 10" and it really felt great to me.

6. Battery Life

Since I wanted to conserve something for a video clip testimonial I am planning to do, I kept it on the high setting for perhaps 25 minutes prior to stopping. The battery was still running it.

7. Sound Level

After about 15 minutes of runtime, my daughter-in-law made an appearance. I was able to hold a conversation with her while working. With a gas-powered trimmer, that is not possible. No, it is not "murmur" quiet. But you can still chat without screaming your head off, as well as filling up the discussion with a lot of "whats"?

8. Add-On Capacities

The fact that the DIL came around was because she had actually been busy herself with the grandkids. That's why I called a halt to the weed attack after simply 25 minutes.

I walked around the side of the home to see she had made a start at clearing the masses of dead fallen leaves that had collected on the side of the house during the winter months. I went to the shed and grabbed the Greenworks Pro Blower. I love this blower.

It's super powerful. It was blowing lots of weeds with a wet base layer around with absolutely no problem.

9. More About the Battery Life/Runtime

After about five minutes, the battery gave up the ghost. So that means the battery has a total of about 30 minutes on the high setting in very very tall weeds—tolerable. The following time I weed whack, I will not require the high setup.

I went in and put the 4Ah battery on the charger and also brought out the 40V 2Ah battery I had from the chainsaw. Perfect fit. I ended up blowing the leaves out of the yard.

Then the DIL wanted a turn with the new weed eater. So I gave it to her and, after about five minutes, she declared it good and she would use it. I thought it would be too heavy for her, especially as she's only 5' 3".

10. Overall View

With the weight and no shoulder strap being the only downside, I was really impressed with what this thing might do, as well as very satisfied that I needed to purchase no different backyard attachments as I'd had to with the gas-powered trimmer.

I am so impressed that I'm going to add a spare 40V 4Ah battery to the arsenal. And that should be enough to get me through the whole one acre.

With the Greenworks trimmer, you'll whip your yard or lawn into shape in no time.

With the Greenworks trimmer, you'll whip your yard or lawn into shape in no time.

Detailed Assembly Instructions

Here's a comprehensive look at the string trimmer and edger.


  • 40V lithium-ion battery
  • 14” cutting path
  • 4-position pivoting head
  • Dual spool
  • 080” single line auto-feed head
  • Total weight (with installed 40V 4Ah battery): 12 pounds


The string trimmer arrived without any damage. The packaging was tough and also held the device and the different items securely. Absolutely nothing came out of the package while in transit.


The Greenworks 14" 40V Cordless String Trimmer called for some assembly.

The guard had to be attached by placing it onto the electric motor, turning it 450°, as well as placing and tightening up two Phillips head screws. You'll need your own screwdriver for that.

Next, you are required to set up the front handlebar. It's a simple process of sliding two plastic pieces over the top section of the trimmer shaft.

The handbook (which is easy to follow) recommends adjusting the supporting front handlebar for optimal balance. Prior to doing that, I would suggest mounting the battery in the slot situated in the rear. Take care to ensure that you can change the balance properly.

For the best balance, simply relocate the handle up until it really feels right and tighten the T-handled knob to squeeze the two pieces of plastic with each other around the upper shaft.

Balancing the String Trimmer

When you have the unit correctly balanced, adjust the cutting head so it's pretty much parallel with the ground. This is an easy job—Greenworks developed a head that rotates with four settings—so you should be able to locate a position that works perfectly for you.

Troubleshooting With the Greenworks Trimmer and Edger

Here's a detailed account of my personal experience in using the trimmer and edger along with some troubleshooting tips.

We Had a Problem With the Cutting Line

When I first set up the Greenworks trimmer, I faced difficulty with the cutting line straight away. After trimming for maybe 45 seconds, the string broke off inside the spool.

I tried to fix the problem by opening the cutting head (after getting rid of the battery pack), as well as pulling out a 14" area of cutting line from the spool. After that, I put the spindle back into the cutting head and tried it again.

It broke again, so I contacted Greenworks to see if they might suggest any type of fix. They said that maybe it was a defective line/spool and sent me a new one (together with a brand new spindle of cutting line).

However, despite having the new pre-wrapped spindle set up, I had the same trouble all over again. There appears to be a problem with the way the spool is wound—the line is so tightly overlapped inside the spindle that it's not able to breakthrough.

I tried winding a new line on an empty spindle. This did take care of the issue of the line breaking inside the spindle, but I faced another problem—the line wouldn't auto-feed.

The Greenworks 14" 40V 4Ah Cordless String Trimmer version 21362 is specifically created to instantly feed out the cutting line when it gets short.

After a couple more attempts at manually pulling the line, it came right. I have no idea why. Perhaps it loosened up a little inside the spool, or maybe the feeder line was a little too tight and a few manual pulls made it a little bigger. Anyway, the bonus is I have a spare spool.

The Edger Is Fantastic

To turn the Greenwork Trimmer from a trimmer to an edger, you just rotate the head 90° and roll it on the plastic wheel, which is secured to the guard housing.

It really is a fantastic edger as well. To change it from one to the other is a nice, simple task. There's a button on top of the drive motor that you push in and the spring-mounted head turns automatically 90° to the edging position. You may have to fiddle a little with a quick turn of a few degrees either way but, once seated, it's very secure.

The design of the edger is that it is pulled towards you. You can use the outer edge of the wheel as the guide, and you can then just roll it along the edge. It cuts a perfect line.

The Battery

The trimmer comes with a charger as well as a 40V 4Ah Li-ion battery. The battery arrives totally discharged and will take about 50 minutes to fully charge. Be certain to fully complete the full charge the first time up.

You'll probably require a second backup battery if you plan on doing work that'll take longer than 60 minutes. They can be ordered online anytime.

I like the balance and maneuverability. It cuts well (when it trimmed), and it was an amazing lawn edger.


Greenworks offer a four-year warranty on the trimmer for all parts, workmanship, and defects.

The battery carries a two-year warranty for workmanship and defects. But be sure to stick to the user instructions, otherwise, the warranty will be void.


You might only get 60 minutes of runtime here—or half that if your weeds are a few feet tall—but the power is definitely equivalent to my old gas trimmer. But it's an even more effective engine.

Have a look at the full specifications here

Questions and Answers on the Trimmer

What size line do you need for this model?

Recommended is 0.80'. But this is a generic size, so you can fit other brands.

What is the difference between 2.0Ah and 4.0Ah?

4.0Ah will give you twice the runtime.

Does this come with bump feed?

Yes, it comes with a bump feed dual spool.

Is it a single or double string?

It feeds in as single but comes out as double. The easiest trimmer I've ever owned to load.

Does this have variable speed setting?

Yes, it does.

Can I use the battery from my Greenworks G Max mower for this?

Yes, you can.

What size string replacement?

You can use string up to .080" in diameter

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

Questions & Answers

Question: How do you take the string head off of Greenwork's cordless string trimmer?

Answer: You should see two black plastic clips on either side of the string head. They may be tight. Use a screwdriver to push them in to loosen them if at first, you can't push them in with your finger. A Warning if you do have to use a screwdriver. Best to lay the string head on a bench and press the clips in with the screwdriver. If you use your hand to hold it and the screwdriver slips you will almost certainly stick the screwdriver into the palm of your hand.

Question: Can use the 80V battery from my Greenworks lawnmower with this trimmer?

Answer: Yes, you can.