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What To Look For In Battery Powered String Trimmers


Cordless string trimmers combine the benefits of an electric device – a push start button, zero emissions, no need to maintain the engine, and comparatively silent operation – with the ease and convenience of a gas string trimmer. Go back a few decades, and there were hardly any cordless models available that had the power or battery life to be practically feasible.

Today is another story however, with electric cordless string trimmers that are both durable and practical. Of course, they still aren’t on the exact same level as gas powered models, but they get the job done. Battery powered string trimers are an excellent low cost option for those who only perform small trimming jobs. And since they run on a DC battery and don’t need to be connected to a power outlet, your area of movement won’t be bound by an extension cord. Cordless string trimmers are effective against errand weed and grass growth, but, be warned, most aren’t capable of dealing with hard weed and brush the way gas trimmers are. Developments in battery technology have enhanced the performance of cordless electric trimmers, leading to their enhanced popularity today.

Looking for the best all around weed wackers? Check out our recommendations.

Cordless Electric String Trimmers Comparisons

Model
Cutting SwathBattery Voltage
Warranty
Our Rating
BLACK+DECKER-LST136W-40V-Max-Lithium-String-Trimmer
BLACK+DECKER LST136W
13 inchesLi-Ion
3-year warranty
5
Read Our Review
GreenWorks-21362-G-MAX-40V-Digipro-14-Inch-String-Trimmer
GreenWorks 21362
14 inchesLi-Ion
4-year warranty
4.4
CGT400
CORE CGT400
14 inchesLi-Ion
5-year residential/ 2-year commercial
4.3
Toro-51487-24-Volt-Lithium-Ion-Cordless-String-Trimmer
Toro 51487
12 inchesLi-Ion
7-year retail consumer
4.2
Earthwise-12-Inch-18-Volt-Cordless-Electric-String-Trimmer,-Model-CST00012
Earthwise CST00012
12 inchesNi-Cad
2-year warranty
3.8

Features Of Cordless Electric String Trimmers

According to gardening experts, cordless string trimmers work best when they are used to trim and edge small lawns. Their battery lasts from fifteen to sixty minutes, depending on the particular model, although we’ve also seen the battery time being less than what the manufacturer quoted. You won’t get far if you try to tackle overgrown yards or vast acreage with these trimmers – there are only a few that are capable of handling anything more than medium duty tasks.

Modern Cordless String Trimmers Characteristics

rechargeable batteriesRechargeable batteries for gardening tools, on an average, run between 45 and 60 minutes, so if you’re going to be handling larger projects, it is wise to keep a spare battery close at hand so you’re not stuck with waiting for the used battery to recharge.

ni-cadString trimmers running on nickel cadmium batteries are normally the cheapest of the cordless string trimmer variety. These batteries are heavier, and they experience a reduction in performance and power as the battery goes down with use.

Li-Ion batteriesThese are the most modern powering solution for cordless string trimmers. Li-Ion batteries come in different voltage levels – 18V, 20V, 24V and 40V.

Modern Batteries Properties

Earthwise-12-Inch-18-Volt-Cordless-Electric-String-Trimmer,-Model-CST00012They don’t weight much – these batteries can be as much as 50% lighter than Nickel Cadmium batteries, so the string trimmer will weigh less as a whole.

ni-cadString trimmers running on nickel cadmium batteries are normally the cheapest of the cordless string trimmer variety. These batteries are heavier, and they experience a reduction in performance and power as the battery goes down with use.

GreenWorks-21362-G-MAX-40V-Digipro-14-Inch-String-TrimmerThe number of recharges you can get out of them is up to thrice as much as a comparable Nickel Cadmium battery, after which you’ll have to replace them.

Trimmer Shaft

GreenWorks-21362-G-MAX-40V-Digipro-14-Inch-String-TrimmerString trimmers that have curved shafts are good for dealing with weed and grass in open lawns. Due to their curved design, they aren’t as good when used in tight spaces requiring manoeuvrability e.g. under a fence or hedge. They are generally regarded as easier to use compared to straight shaft trimmers.

BLACK+DECKER-LST136W-40V-Max-Lithium-String-TrimmerString trimmers with straight shafts are much better at handling tight spaces. You can get up close to the hard to reach edges of your garden, or areas that are farther away from yourself.

Toro-51487-24-Volt-Lithium-Ion-Cordless-String-TrimmerSome models come with a telescoping shaft that you can shorten or lengthen as per your requirements.

Fields Edge M220 Walk Behind String MowerSome string trimmers have 2-in-1 capability i.e. you can use them for both of the purposes described above.

Tips For Buying A Cordless String Trimmer

li-on battery

Power Output And Longevity

The period of time for which you will be able to use your cordless string trimmer depends on the battery that it runs on. If it’s a Nickel Cadmium battery, then it will require more frequent recharges, and will also have a smaller battery life. Even worse, you’ll experience a drop in the performance of the string trimmer as the battery runs low. On the other hand, cordless string trimmers running on Lithium Ion batteries will last longer each run, require fewer recharges and will have a longer overall battery life. They will also perform consistently throughout the battery’s discharge cycle.

Weight

Choose a string trimmer that is both light and strong – since you’ll be dealing with bush and rock that could otherwise damage it. Beyond that, the weight of the string trimmer is largely dependent on the battery type. Nickel Cadmium batteries are heavier than Lithium Ion batteries.

Design

If you will be working mostly in open spaces, a curved shaft string trimmer is recommended – it easier to use and more ergonomic. A straight shaft trimmer is only recommended if you will be sticking to smaller, tighter lawns with lots of hard to reach corners. If you aren’t sure as to where you will be using your string trimmer, go for a 2-in-1 solution that gives you the freedom of choice of using both design styles.

Cost

The initial cost of the cordless string trimmer depends on the battery and the quality of the build materials. Ideally, you should scrimp on neither, since the battery determines the overall performance of the device while the build quality determines how long it will last you. Even so, if you are tight on cash, you do have some options in the battery department – go for a lower rated Nickel Cadmium battery if you must, but remember all the disadvantages it comes with, which have been described above. Also remember that even though you will be reducing the initial cost, the running cost of the Nickel Cadmium battery will be greater due to the more frequent recharges and replacements it requires.

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You might also like to check out brush cutter reviews here.

Top 5 Cordless Electric String Trimmers

GreenWorks 21362 G-MAX 40V Digipro 14-Inch String Trimmer

Quick Info

  • Cutting swath: 14 inches
  • Battery type: Li-Ion
  • Battery voltage: 40V
  • Warranty: 4 years

GreenWorks-21362-G-MAX-40V-Digipro-14-Inch-String-Trimmer

The DigiPro Brushless String Trimmer packs a 14 inch cutting swath and a .080 bump feed for easy line advancement and cutting. Its straight shaft design allows for better viewing of the area ahead, so you can use it seamlessly. The top mount motor head is detachable and can be used with multiple attachments which are part of the GreenWorks G-Max System, as well as others from Craftsman, Ryobi and TrimmerPlus. The 40V battery is Li-Ion, and you can choose between 2AH and 4AH capacity for lighter or heavier jobs. The battery is also compatible with other GreenWorks G-Max tools, which makes it an economical purchase. Suitable for those who require a versatile garden maintenance system.

Pros

  • Detachable top mount motor head allows for versatility.
  • Can work in tandem with products from other manufacturers.

Cons

  • Bump feed line system instead of the newer automatic constant feed one.
  • 5 hour charging time doesn’t work for professionals.

Suitable for those who require a versatile garden maintenance system.

BLACK+DECKER LST136W 40V Max Lithium String Trimmer

Quick Info

  • Cutting swath: 13 inches
  • Battery type: Li-Ion
  • Battery voltage: 40V
  • Warranty: 3 years

BLACK+DECKER LST136W 40V Max Lithium String Trimmer

Running on a 40V Lithium-Ion battery, the LST136W lets the user tackle a mile long strip of overgrown grass on just one charge. Its power command dial lets the user choose between a high power setting and a low power setting to get maximum performance or extended battery life, as desired. The LST136W’s can be rotated up to 180 degrees to rapidly change its mode from trimming to edging and back. The automatic feed spool system yields more string for cutting when it is needed, so you don’t have to bump the string trimer as you’re working to get more string out. It takes around an hour to charge the batteries, which means you won’t be grounded for long when tackling bigger jobs.

Pros

  • Freedom to choose between power and battery conservation.
  • Automatic feed system is convenient.
  • Relatively smaller recharge time.

Cons

  • None

Suited for those who want the freedom of choosing between power and battery saving.

CORE GasLess Power CGT400 CGTSD Gasless Powered Trimmer

Quick Info

  • Cutting swath: 14 inches
  • Potential durability issues with the battery.
  • Longer recharge time.
  • Battery type: Li-Ion
  • Battery voltage: 21V
  • Warranty: 5 years residential / 2 years commercial

Lasting around 70 minutes on average, the Core CGT400’s rechargeable battery is on par with a standard string trimmer utilizing a tank of gas. Inside the unit, a prismatic high-energy power cell operates in tandem with smart circuitry to enable this weed trimmer to work for a considerably longer period than its competition. Its head rotates at around 7000 RPM, with a torque output of 5000 RPM, that is cutting power equivalent to a 25cc 2 cycle gas trimmer engine. This string trimmer utilizes a dual-line bump feed system, which is a design choice by the manufacturer to eliminate the maintenance requirements inherent to automatic feed systems. It also comes with two operating modes – a power mode for high performance, and a light mode for conserving battery life. The downside is that its battery requires a hefty 3 hour recharge time.

Pros

  • Efficient, longer lasting battery.
  • Solid performance in the field.

Cons

  • Potential durability issues with the battery.
  • Longer recharge time.

Suited to those looking for a powerful yet long running cordless weed trimmer.

Toro 51487 24-Volt Lithium-Ion Cordless String Trimmer,12-Inch

Quick Info

  • Cutting swath: 12 inches
  • Battery type: Li-Ion
  • Battery voltage: 24V
  • Warranty: 7 years retail consumer

Remington wheeled trimmer with 22 inch cutting diameter

The Toro 51487 Cordless String Trimmer packs a 24V Li-Ion battery for enhanced cutting power, as well as a convenient LED charge meter that keeps you updated about the battery’s level as you work in the field. It has a 12’’ line length, but you can also use 10’’ to conserve power. It utilizes an automatic feed system whereby string of the correct cutting length is fed by the push of a trigger. An assist handle is in place to improve the user’s control of the trimmer. Another button is used to switch between trimming and edging functionality, and there’s even a guide wheel included for precise edging. Furthermore, it has an ergonomic handle that gives a snug grip which reduces fatigue due to prolonged use.

Pros

  • Convenient LED meter informs user of battery level in real time.
  • Automatic feed system and button based function switching enhances usability.
  • Ergonomic grip.

Cons

  • None

Suited to those looking for a power efficient, ergonomic and multifunctional string trimmer.

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Earthwise 12-Inch 18-Volt Cordless Electric String Trimmer

Quick Info

  • Cutting swath: 12 inches
  • Battery type: Ni-Cad
  • Battery voltage: 18V
  • Warranty: 2 years

Earthwise 12-Inch 18-Volt Cordless Electric String Trimmer

An easy to use walk behind trimmer that gets the job done, even when you’re facing some seriously tall and tough weed growth. It has received lots of praise for the reliability and performance of its efficient and powerful 4 stroke OHV engine. The manufacturer is clearly concerned about the convenience of the user since the lawn mower comes with a folding handle that makes it easy to store and transport.

The off-set trimmer head feature enables the user to trim in difficult to reach areas, and the 14 inch ball bearing wheels are capable of tackling tough ground.

Pros

  • Sufficient power output for a Ni-Cad powered string trimmer.
  • Multiple head positions allow for a greater degree of selection for the cutting angle.
  • Extremely cheap.

Cons

  • Nickel Cadmium batteries are weak, and less durable.

Suited for those who want reasonable power output but are willing to compromise on battery life.

Conclusion

After analysing and reviewing the performance of various cordless string trimmer models, we arrive at the conclusion that the Black & Decker LST136W, is the optimum choice for most users. With its efficient battery, choice between power output modes, automatic feed system, and fast charging time, there isn’t another competitor that quite matches its particular combination of solid features. Even better, it is moderately priced which means it also suits those on tighter budgets.

In any case, you should bear in mind that the optimum cordless string trimmer for you will be the one which matches your particular requirements – where one person may require a short lasting yet powerful trimmer for their smaller lawn, another may be happy with a somewhat less powerful yet longer lasting trimmer for their acreage. Having a clear idea of what you require will help you from a lot of expense and headache in the long run.

About The Author

Timothy Moore

Timothy Moore is the lead editor of Back Yard Boss and is a lifelong backyard enthusiast. He grew up immersed in the outdoors, camping every weekend and tending to the backyard with his family. He spends most of his days (and even nights) lounging on the patio while firing up the grill and admiring his handiwork around the property. He spent most of his life watching his father do wood working and is a self-taught landscaper, doing it mostly as a hobby. Now he uses his vast experience in the field to write fun, but informative, articles for you good people!

4 Comments

  1. David S Crew

    Just a fair warning from someone who used the Black & Decker. The blade used to cut the string can break off and if it does, you have to get a new guard to replace it.

    Reply
    • Timothy Moore

      Thanks for letting us know David.

      Reply
  2. Steven

    Hi Timothy,

    Great article, thanks for all the info! I think I’m going to order the Black and Decker now!

    Only complaint is that I don’t think it’s fair to call anything battery powered zero emissions for a couple of reasons. One is that the process to make these batteries is extremely dirty, batteries need to be replaced after an amount of time and most batteries end up in land fills after use. Two, much of the electric power in the US is not coming from renewable sources.

    There is not allot of good data on what a true emission comparison would look like, but it’s safe to say that these are not zero emissions, instead maybe low emissions?

    Just a thought. Thanks again.

    -Steve

    Reply
    • Timothy Moore

      Hey Steve,
      I’m glad you enjoyed the article! When you put it that way concerning zero emissions, you make some great points. There may not be emissions during use of a battery-powered string trimmer, but to call it low emissions when you look at the bigger picture is probably a more suitable choice of words.

      Reply

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