By Glenda Taylor and Mark Wolfe | Updated Feb 1, 2022 8:44 AM

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The Best Battery Trimmer Option Handy outdoor power tools make quick work of tackling overgrown weeds and grass, giving the yard a tidy look and trimming hedges and shrubs. For ensuring a polished look to a lawn, the best string trimmer is a great investment. These yard-care tools spin a cutting head loaded with nylon string (instead of a fixed blade) to cleanly trim the grass at the edge of a lawn or mow down weedy areas. Though gas and electric models have dominated, new and improved battery-powered versions don’t require mixing fuel or storing gasoline like gas string trimmers do, nor are they limited by the length of an extension cord, like corded electric string trimmers are.

Even among battery models there are variations, with some better suited to different-size yards, users, and budgets. So to help consumers make the right choice, we tested some of the most popular string trimmers around to find out how they perform under real-world conditions. To qualify as a top pick, a string trimmer should be durable, powerful, and easy to operate. The string line should exit the reel easily with no need to constantly remove the reel cover and untangle the line.

The following battery-powered string trimmers are at the top of their class. Anyone looking to invest in a trimmer is likely to find one here to fit their landscaping needs.

When shopping for string trimmers, also known as weed eaters, keep in mind yard size, how often the tool will be used, and the height and strength of the primary user. The following key considerations will help in selection.

Trim width, also called swath width, indicates how wide a path the trimmer will cut through weeds in a single pass. Many models on the market today feature swath widths of 10 to 18 inches. The wider the width, the more power the trimmer must have, which often means the tool will be heavier because it will require a larger, more powerful battery.

Running a string trimmer requires a hefty dose of power. Though most of today’s trimmers run on rechargeable lithium-ion (Li-ion) batteries, a few accept nickel cadmium (NiCad) batteries. Li-ion batteries are more powerful, but NiCad batteries are less expensive (an average of $70 to $125 less). Li-ion batteries also are smaller, hold a charge longer, and provide full power throughout the discharge cycle.

NiCad batteries suffer from “memory effect,” meaning if the battery is used before it has fully charged—or if it’s recharged before its power depletes—it will “remember” the earlier charge level and won’t hold a longer charge in the future. If choosing a trimmer that has a NiCad battery, let it charge fully before use and drain completely before charging. For most users, a string trimmer with a Li-ion battery will be the best choice.

Along with battery type, consider how much operating power the battery has, which is measured in volts. Today’s rechargeable string trimmer batteries average from 18 volts up to 60 volts of power. More powerful batteries at the high end often are intended for commercial use and can cost $200 or more per battery.

Some string trimmers in this category sell without a battery (or battery charger), which the user must purchase separately. This could be a cost-saving benefit for those who are adding to a same-brand, battery-compatible cordless tool collection, since the same battery will power multiple tools. However, it can be more convenient to purchase a kit with multiple batteries in order to have one on the charger while the other is in use.

The “feed” of a string trimmer indicates how the trimmer head releases additional trimmer line as it becomes frayed and broken during use. The standby is a bump feed where the user bumps the bottom of the trimmer (the area where the spool attaches) on the ground to release a few inches of fresh line.

Some newer models feature an auto-feed sensor that gauges the length of the strings and releases more when needed. Still others have a push button to release more line. Auto and button feeds eliminate the need to bump the spool, which can reduce the risk of damage if bumped too hard, but many commercial-type trimmers still use bump feed because it’s quick and easy.

Some string trimmers feature a straight shaft that runs from the handle to the cutting head, while other models feature a distinct curve in the lower shaft about two-thirds of the way down. Some users find curved-shaft trimmers to be easier to operate since the spool end already rests at a handy angle for weed whacking.

Straight shaft trimmers often accommodate interchangeable tools, such as a tree trimmer head, which can be swapped out depending on the task at hand. In general, straight shaft trimmers work better for users at least 6 feet tall, while shorter users will appreciate curved shaft trimmers.

Battery-powered string trimmers have a distinct advantage over gas-powered trimmers when it comes to noise pollution. Gas-powered trimmers are moderately loud, emitting an average of 90 decibels (about as loud as a motorcycle passing by from 25 feet away). By contrast, a cordless string trimmer emits approximately 77 decibels, which is comparable to casual conversation.

Warranty terms vary from one string trimmer to another, ranging from 2 to 5 years and are often limited to tool failure. If a user drops the trimmer and it breaks, the warranty won’t cover the damage. Some retailers offer extended warranties for an additional fee.

These reviews describe the key features of each cordless string trimmer and how the models performed in our backyard tests.

EGO Power+ has made a name for itself in the outdoor power equipment category by building an affordable battery-powered tool line that competes favorably against old-fashioned 2-cycle gas powered equipment. The ST1511T 15-inch String Trimmer proved to be powerful, clean, and quiet. The 56V 2.5Ah lithium-ion battery delivers up to 45 minutes of runtime, with a recharging time of just 50 minutes. The bump-feed trimmer head comes preloaded with 0.080 twisted trimmer line for more cutting force and less noise. Taller users will appreciate the straight shaft design, and the unit weighs in at just over 10 pounds.

In our tests, the EGO string trimmer showed ample power to cut through everything in its path, including overgrown, weedy grass; privet seedlings; and honeysuckle vines. Its well-balanced design, with the heavy battery in back offset by the long straight shaft and ideally positioned grips, made it comfortable to work with and more agile than others we tested. Our only caveat: For seasonal yard cleanup or maintaining larger landscapes, the 45-minute maximum runtime may not be quite enough.

Get the EGO Power+ ST1511T Cordless String Trimmer at Ace Hardware, Lowe’s, or on Amazon.

To give the yard a polished look without breaking the bank, consider the Black & Decker Cordless String Trimmer. It features a 12-inch cutting swath to cut down the corners and clean up the edges of small to medium-size yards. An automatic feed spool means there’s no reason to stop and bump the tool when new string is needed. Two 20-volt lithium-ion batteries are included.

In our tests, this trimmer performed very well in weed-free grass as well as weedy lawn areas. The light weight of just 5.7 pounds makes this trimmer easy to handle without causing arm and shoulder fatigue. The short, straight shaft design is most comfortable for those under 5 feet 9 inches in height. We also liked that with a quick adjustment to the head, the trimmer becomes an edger to neaten up along sidewalks and driveways. In all, we found this affordable tool a solid pick for small obstacle-free landscapes.

Get the BLACK+DECKER Cordless String Trimmer on Amazon, at The Home Depot, or at Walmart.

The Makita XRU15PT1 string trimmer is a premium option to keep the lawn and garden under control. It can handle large yards with enough power to tackle dense weed growth. This cordless string trimmer comes with four 18V 5.0Ah batteries so you’ll never run out of power. Shoppers can purchase this model as a kit that includes a dual battery charger and two sets of batteries, or as “tool only” for those who already have items from the Makita 18V tool platform.

With a long, straight shaft and high-power cutting head, this 10.4-pound trimmer feels like a pro-quality tool. It was well balanced and articulate while trimming around shrubs and between obstacles. It had plenty of power to cut through tough vegetation. In our tests it made nice, clean cuts and crisp edges in the grassy areas and tore through weedy privet seedlings and honeysuckle vines without hesitation. It’s an excellent candidate to replace gas equipment for medium to large landscapes, though the price may be too high for budget buyers.

Get the Makita XRU15PT1 36V LXT Brushless String Trimmer on Amazon or at Mowers Direct.

Weighing just 5.3 pounds, this string trimmer is easy to carry, maneuver, and control with an adjustable handle and a safety trigger switch to prevent accidental starts. The 12-inch trimming radius is suitable for keeping the lawn properly maintained without damaging fencing, decks, trees, or other common yard obstacles.

This cordless string trimmer operates with a 20-volt battery that can last for up to 20 minutes, and a spare battery is included. For edging, simply turn the head and use the built-in wheel to balance as the trimmer string handles the task.

When we used it to trim weedy lawn grass patches and edge the curb and driveway, it made nice clean cuts and tracked well to make good straight edges. The shaft and handle adjusted to comfortably fit our 6-foot user. The tool is amazingly lightweight for the amount of power it offers, but the weight is mostly balanced to the front of the handle, and having to manually counterbalance it while working fatigued our tester. Though not built for heavily weed-infested yards, it has ample power and runtime to clean up curb lines, driveway edges, and otherwise maintain a smaller landscape.

Get the BLACK+DECKER 20V Max String Trimmer/Edger on Amazon or at Walmart.

Those with a small yard may find this lightweight string trimmer an excellent option. It weighs just 5.3 pounds and easily converts from a trimmer to an edging tool; a built-in wheel helps balance the tool while edging. A push-button feed system gives the ability to extend the trimmer string without bumping the 12-inch trimmer head or manually pulling additional string from the trimmer. It comes with two 20-volt batteries and a battery charger, and the battery lasts for up to 20 minutes on a full charge.

This WORX string trimmer tackled our grassy areas with ease, both the weedy and weed-free zones, but it wasn’t as capable on rough areas. We were particularly impressed by the edger function, which we found comfortable and well balanced thanks to the 90-degree shaft rotation capability. The adjustable trimmer head and upper handle let users customize the working angle, but the process of doing so proved clunky: The user must reach down and turn a rather stiff knob at the connection point between the shaft and cutting head to unlock and relock the angle for each adjustment.

Get the WORX GT 3.0 20V PowerShare Cordless Trimmer on Amazon, at Lowe’s, or at Tractor Supply Co.

While plenty of string trimmers also function as edgers, we found this model to have the best dual-function design. At the push of a button, the trimming head on the WORX WG170 GT Revolution 20V trimmer converts to an edger that rolls easily along the edge of a sidewalk or driveway. The head tilts up to 90 degrees, making it easy to reach weeds on slopes while standing comfortably.

It comes with two batteries plus a charger and three extra spools of trimmer line. The string trimmer also boasts a handy spacer guard that keeps it from bumping into plants, and the shaft adjusts to suit taller or shorter users. It cuts a 12-inch swath and operates on a 20V lithium-ion battery. In our yard, this trimmer cut through and created a crisp edge on both weedless and weedy lawn areas. We really liked the easy adjustable feature on the trimmer head: A twist lock holds it in just the right position, up to 90 degrees, for a customized working angle for users of different heights. Also, the batteries are interchangeable with many other WORX 20V cordless tools.

Get the WORX WG170 GT Revolution 20V String Trimmer on Amazon, at Target, or at Walmart.

The Greenworks Pro 80V Cordless String Trimmer is a quality trimmer that adapts for a variety of other functions with attachments such as a brush cutter. (However, attachments are sold separately.) The 2Ah battery provides up to 45 minutes of runtime and recharges in just 30 minutes. The brushless electric motor is efficient and quiet, providing plenty of torque to cut through heavy weeds without the noise and smell of a gas-powered unit.

In our test areas, the Greenworks trimmer was powerful enough to cut through the toughest weeds and vines with ease. The heavy battery weighs the machine down toward the rear, but the included adjustable shoulder strap makes operation comfortable. The battery is compatible with other Greenworks 80V tools. Just don’t get too excited about the variable speed trigger: Although it’s intended to allow a gradual increase from “off” to “high” speed, we found the range of movement between the two to be minuscule; in effect, the trimmer is either “off” or “on.”

Get the Greenworks Pro 80V Cordless String Trimmer on Amazon, at Walmart, or at Tractor Supply Co.

Those looking to replace a gas-powered string trimmer with a clean, quiet, and powerful battery-powered one should take a close look at the EGO Power+ ST1511T. Anyone with a smaller landscape and stringent storage space will appreciate the WORX WG170. It offers the versatility of both trimmer and edger capabilities, folds neatly for storage, and shares its battery with dozens of compatible yard tools.

To truly test these battery-powered string trimmers, we started by assembling the tools and charging the batteries. Most trimmers arrived with the batteries about 25 percent charged right out of the box, but a full charge allowed us to gauge runtime at full power. Although some of the trimmers offer lower power settings that could extend runtime, we found that the lower settings simply made them less capable, and so we ran them at full power for testing.

We put each trimmer through its paces in a variety of real-world scenarios: manicured grass, weedy grass, and natural areas featuring coarse, weedy seedlings and vines. To earn a spot in our lineup, the lightweight 20V trimmers had to deliver a clean, crisp cut in the clean and weedy grass sections. In addition to trimming the grass zones, we used the 36V, 56V, and 80V models to aggressively cut through the woody, viny growth in the natural areas. Along with cutting power, we tested for battery runtime, maneuverability, and operator comfort.

Those who are still unsure about how to use a battery string trimmer may find the following answers to common questions about these tools helpful.

A string trimmer is used to cut and control weed growth around the home and garden. However, light-duty trimmers may have issues with very dense weed growth.

A string trimmer can be used to cut grass, though you need to be careful not to cut the grass too short while trying to keep the trimmer balanced. It isn’t the easiest way to cut the grass, but it is possible.

Yes, a string trimmer can be used for edging the garden, driveway, walkway, or sidewalk. If you have a large yard, it may be better to invest in a separate edging tool.

String trimmer batteries average from 18 volts up to 80 volts. Typically, the higher the voltage, the longer the battery life.

Hold the string trimmer perpendicular to the lawn to keep the cut even. Position the head about 4 inches off the soil so the string has space to rotate. The string should rotate and cut through the grass and dirt. As you move along the desired borders, keep the head balanced and even. Clean up the cut grass and dirt to finish the job.

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