Kobalt 40V String Trimmer and Hedge Trimmer Review

Kobalt 40V String Trimmer and Hedge Trimmer
PTR Review
  • Performance 8.0
  • Power 8.0
  • Run-time 9.0
  • Features 7.0
  • Value 9.0

Cobalt's OPE tools definitely have the power to hold their own against corded and gas models. For the majority of homeowners these tools will serve their purposes nicely in keeping their landscaping in check and looking good.

Overall Score 8.2 (out of 10)

Remember those early Saturday mornings as child when you were trying to sleep in while someone was doing yard work? Do you remember how quiet it wasn’t?  You were most likely awoken from your attempts to sleep until noon by the sounds of gas powered outdoor equipment. Our kids today might not have the same annoyance as we did back then. Today we have the options of eco-friendly equipment available in the market. Joining the revolution of battery powered outdoor power equipment the Kobalt 40V Max Outdoor Power Equipment (OPE), and it will have you wishing it was around back when you were growing up. Check out our review of the Kobalt 40V Max Lithium-Ion Mower, Blower, and Chainsaw for even more on this new cordless OPE series from Lowe’s.

According to Kobalt’s website, “at the heart of the Kobalt OPE line is a high-performance 40V Max, lithium-ion battery that delivers fade-free performance. That means every battery and every tool delivers full power up until the point where the battery runs out of juice. Then you just pop in another battery and keep working at full power.”

What’s great about Kobalt’s 40V Max OPE is that the complete line works off the same rechargeable, interchangeable battery platform.  “If the battery in one tool runs out, just pop in a battery from one of the other tool in the line and keep going”

I had the privilege of testing out the new Kobalt 40V Max String Trimmer (KST 120X – 06) and the Kobalt 40V Max Hedge Trimmer (KHT 240-06).  At the first glance you will easily recognize these tools because of the Kobalt blue color. The color that says “dependable” when it comes to hand tools. Does it hold true in this situation? According to their website, Kobalt “invested countless hours in consumer and product research,  product design, and exhaustive quality assurance testing to bring you outdoor power tools that deliver the perfect balance between performance and affordable value.”  Kobalt designed these tools to be tough so they stand behind them with a best-in-class, 5 year Hassle-Free Guarantee.

While I will dive into each tool in depth momentarily, one thing I noticed immediately when I picked up these Lithium-ion powered options is the difference in weight. Even though they are lighter, you might get the impression that they are inferior to their heavier gas powered cousins, like the well-regarded Echo SRM-280T String Trimmer. One of the goals in reviewing these is to determine whether or not they will be able to keep up—and in what scenarios having less power than a pro gas model might or might not be an issue.

Kobalt 40V Max String Trimmer model # KST 120x -06

At first look, the string trimmer is a two-piece design and what immediately stands out is the motor. It sits directly above the spool unlike gas powered engines that are at at the top. The motor does not appear to be big and cumbersome and overall motor/spool weighs approximately 4 pounds. The spool is a dual line auto feed system, which I found to be excellent – it did not require any bumping to feed the line. The line is 0.065 in (1.65mm) nylon monofilament and can be replaced by either refilling the spool or replacing with a new pre-wound spool.

The rest of the components in this end of the trimmer appear to be standard with other trimmers. The edge guard can be easily flipped into or out of position and the protective guard requires a one-time installation out of the box.  The motor/spool end can be connected to the control/battery end and locked in place by aligning the upper and lower trimmer tubes and twisting the coupler in place.


The position of the front auxiliary handle can be adjusted along the upper tube using the fastening clamp and tightening fastening knob. The inside part of the auxiliary handle has areas of dimples for grip that reminds me of a golf ball – it has texture and yet is smooth. The control consists of a trigger, trigger lock, and palm lock. The grip in the control area is a grey rubber material with strategically place texturing for either left handed or right handed users. The 40V battery can be installed by aligning it and pushing it down into the cavity housing and removed by pressing the release button on the right.  With the battery installed, the upper half weighs approximately 5 pounds. Overall you are looking at a trimmer with battery at around 9 pounds.

Installation of the protective guard was easy, however the piece cracked when the screw that holds the guard in place was over-tightened. There was no mention of caution against over-tightening in the manual and there seemed to be no natural stop for the screw to prevent over-tightening.  Installation of the front auxiliary handle and connecting the upper/lower trimmer tube were easy as well. Everything held in place tightly throughout the use. Because the motor is located above the spool I found little to no vibration at all during use. I found the rubberized grip to be comfortable and just right to prevent slipping out of my hand.


The design of the auxiliary handle is perfect for use as a trimmer or to flip it as an edger. The dimpled area is placed exactly where my fingers would be which gave a smooth and yet textured surface like a golf ball. It is not as “grippy” as the control handle but I did not find this to be a negative or positive.

After it was assembled, what stuck out was the overall length. I’m not a tall guy by any means (5’ 7″ on a good day) but it seemed to be a long trimmer and I found it somewhat difficult to use at first. Even though the auxiliary handle is adjustable, it also changes the way the trimmer is balanced.  Along with the motor being in the front it made my left (Auxiliary handle) arm fatigue compared to the right arm fatigue from the gas powered I’ve used in the past. I found myself switching arms a few times at first (I’ve done the same with gas powered) until I found the best way to use it.  Being battery powered there was no heat coming from the control end, which allows the ability to place it next to your body or rest your arm against it without fear of being burned. Once I found a good technique it was smooth sailing.


I was able to use it for about an hour before the battery ran out. I loved the dual line auto feed feature and the variable speed trigger. No bumping to feed the lines and have the ability to work longer if lower speed is used to save battery. But who wants to go half powered? Full blast was a lot of fun and powerful!  Most of all it was a lot quieter than a gas powered trimmer.

There was some confusion when it came to testing the trimmer’s ability as an edger. Although the manual suggested I could just pop the edger guide down, flip it over, and edge, I found the reality of that to be tricky. The edger guide is about 1″ from the string, but at almost the same length as what the line is cut to. The guard blocked my view so I was unable to see where I was actually edging. This resulted in anything but a nice clean edge along the driveway. I tried using it in several different positions and even got Kenny Koehler to give it a shot, but its use in this function was just awkward.



  • Cuts up to 1.75 Miles on 1 charge on slow speed
  • Included 40V Lithium-Ion battery charges in under an hour
  • Dual line auto feed head
  • 12 inch cut diameter
  • Variable speed trigger
  • Flip to edge grip for easy edger conversion
  • $149 MSRP
  • 5 Year Tool, 3 Year Battery Hassle-Free Guarantee

I was skeptical of the performance of a battery powered trimmer when I was asked to review this one. Just hearing the speed of the string trimmer at full blast sent a smile to my face, dispelling my concern in terms of power. As a trimmer, I can highly recommend this for home owners looking for a gas free, cordless option. Unfortunately, this model just doesn’t feel at home as an edger around the driveway and other solid barriers. I’d also point out that considering the trimmer function only, this would have scored an impressive 4.25 on its overall rating. So if you’re in need of a cordless trimmer only, Kobalt has an attractive option at this price point. Plus, with stores all across the country, any issues than may come up can be dealt with quickly at your local Lowe’s.

Kobalt 40V Max Hedge Trimmer model # KHT 240-06

This hedge trimmer is the little engine that could. The 40 volt power cut through the hedges beyond my expectation. I was impressed. I did not think a battery powered hedge trimmer could handle what I put it through. (Really I have a lot of hedges!) It lasted well past an hour for me, although I did take some quick breaks here and there to clear branches and check the shrub height.


The auxiliary handle is similar to the string trimmer and was comfortable to use. The grip in the trigger control area is also similar to the string trimmer which I found on the hedge trimmer to be excellent. It was quiet and simple to use with either hand. It weighs approximately 8 pounds with the battery in place making the balance and weight great. I had no arm fatigue from using it over an hour.

The blade is sharp and even though it has a 24 inch blade, the cutting area is 22 inches that does not come all the way to the end like most hedge trimmers. I did not find this to be a problem at all though. However, I did have difficult time cutting through two ¾ inch branch at the same time, but that’s a challenge for most hedge trimmers on the market regardless of power source. It might have been the hardiness of plant because I had no further problems after that point with other shrubs.


Feature Summary

  • Up to 2800 strokes per minute
  • Includes 40V Lithium–Ion battery.
  • 3/4 inch branch cutting capacity
  • 24 inch blade (22 inches usable)
  • $149 MSRP
  • 5 Year Tool, 3 Year Battery Hassle-Free Guarantee

At the end of the day, the performance was on par with what you’d expect in a cordless hedge trimmer at this price point. The 40V battery keeps the trimmer’s run time above average and should allow most homeowners to do their routine maintenance with a single battery. I was indeed able to cut through 3/4″ branches and the 3800 strokes per minute cut through the majority of my hedges with ease.

Overall I really enjoyed using these trimmers. No more mixing gas and oil or cut lines from electric hedge trimmers. One thing that I think could be improved is the battery cavity area. It could use a trap door that closes to prevent debris from getting into the area when storing without the battery in place. While there is room for improvement in a couple of areas, Kobalt did a nice job with this line of 40V Outdoor Power Equipment.

Related articles

Stihl Battery-Powered Edger | FCA 135 and 140

Stihl Battery-Powered Edger Targets Gas Replacement for Professionals Stihl’s 135 platform is dedicated to helping professional lawn care crews make the transition from gas to battery power without compromising performance. As part of that system, Stihl FCA 135 and FCA 140 battery-powered edger options break new ground. Stihl Battery-Powered Edger | The Big Deal Right […]

Makita 40V max XGT Couple Shaft Attachment System

Makita 40V max XGT Couple Shaft Offers Gas Replacement Power on a Single Battery Makita XGT tools and equipment promise higher performance and it’s a really big deal for the lawn care side of their business. The Makita 40V max XGT Couple Shaft attachment system targets multi-tool versatility with battery-powered benefits. Makita 40V max XGT […]

Notify of
Newest Most Voted
Inline Feedbacks
View all comments

The 40V performance in these two models was surprisingly adequate for the trimming we needed done. I’ll admit that I had doubts about the hedge trimmer, but it did well!


Would you do a head-to-head comparison of the Kobalt system to the EGO system? They are the flagship/exclusive brands from the two biggest home improvement stores, Lowes and Home Depot.

C Kolmer

I was looking for a trimmer for a small patch that I could trim easily. I like the feel and it has the power I needed for the job. One problem, why does it keep stopping. I love the use of it and would like to continue.

E Spencer

About a year ago, I purchased a Black & Decker 36v rechargeable hedge trimmer. It was adequate for the hedges in my yard & surprisingly light weight. Well the other day I was trimming my hedges & it started making this rattling sound then it stopped working. i looked online to find a B&D repair place. None in my area. I would have had to mail it, (at my expense) & then pay to have them repair it. Not wanting to make the same mistake, I purchased a Kobalt 40v. I just used it & am very happy with the… Read more »

Cardale Bates

My Kobalt 240 40v has been the best trimmer tool ive ever purchased and I think I got a little carried away with it because now it seems as if the blade is locked up. Its making a clicking noise and I cant figure out what it is! Can anyone please give some kind of advice of what I need to do!! If you can help that would mean a lot!! Thanks in advance!


Hello Cardale bates.

In reading lowes website, their kobalt trimmer has a 5 year warranty so why not to just exchange it instead of trying to figure out what is wrong with it ?


LOWESSHOPPER, that’s a 5-year MANUFACTURER’S warranty, not a Lowe’s return or exchange timeframe… HUGE difference!


I just got the Kobalt #506886 trimmer but I put it together before I put handle on in middle How do I get it open again? Please yes I am a lady and yes I am blonde


I bought my Kobalt 40 Volt trimmer about a Year ago the Trimmer Guard breaks very Easy I called Kobalt to get a new Guard it was 35.18 to send a new Guard its made of Plastic so you have to be very Careful!

Russ Swan

Kobalt claims the battery can go for 1.75 miles before re-charging. Not even close. I have only an acre and have to charge the battery 2 – 3 times just to go around my house and trim around the plants. In hot weather, the battery overheats very easily, But that’s when I cut grass and trim edges – not in the winter.


I just got my trimmer/weed wacker and was happily going about my business and it up and stopped. I changed the battery and still nothing. have any clues as to what happened????


I’ve rewound the cartridge but can’t figure out how to snap it back on the trimmer. Any hints and/or pictures?


Hm, might be missing a cap that goes over the cartridge?

Endlesspathable .

My review of same trimmer on Aug 2016, with a scale of 1 (worst) – 10 (best): 4. Pro: Quick charge (charger incl) in 1 hr. Battery has about 20-30 min charge, fair enough for residential 1 acre or less lot. Relatively light unit, somewhat adjustable center handle, easy to operate. Balance is fair for me (5’8″” male). Con: Dual sided spool mechanism is a disaster. Even when following instructions exactly, the line feed consistently fails to feed line, or alternatively fails to lock properly and abruptly starts spooling out one of the lines without stopping. I find myself stopping… Read more »


Mine constantly had problems with the line feed jamming up and required manually pulling it out,then the spool cover disentigrated. I called Lowes service center and they said it is a normal wear and tear item and not covered under warranty, but they don’t sell it in stores, it’s order only for $15 plus shipping and handling $10. $25 for a cheap piece of plastic that should be sold in stores for $3.BAD business practice Lowes!!!!

John Harding

To begin with, I had a devil of a time getting the battery to make contact in the charger. Very fickle. The trimmer has plenty of power but the line feed is a disaster. I was constantly having to stop and manually dispense “string”. I have a pretty large yard and I went around doing everything and still had power to spare. The edger guide is a joke. It constantly tangled with the line and is too flimsy to serve any purpose. I give this 5 stars out of 10 at a trimmer; . 3 as an edger. and a… Read more »


I found the edger works better with a fixed down position. I put a bar across the top of the head.A 3 inch wheel mounted on the back of the guard at right angle to the shaft and set at 1 and 1/2 in.or whatever hgt. You prefer keeps cutting hft.fixed and you donnot have to pick up the trimmer,just roll it back and forth.Less tiring.T

Kathleen Humphrey

I’m in my second season of using this trimmer. The spool cover is so flimsy and it finally bit the dust. I called Kobalt to order a new spool cover. The part is $3 and the SHIPPING IS $15 because of Canadian currency. WHAT???? This is ridiculous! I don’t even like the performance of this trimmer. It won’t advance the string. I have to turn it over multiple times to pull out the string. $150 and it’s ready for the junk pile. Do yourself a favor and read reviews on trimmers before you buy. I’m headed to Home Depot for… Read more »

Would love your thoughts, please comment.x