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Battery powered string trimmer: best cordless weed picks

Battery-powered string trimmers cut weeds and edge lawn borders on a single charge without gas fumes, mixing oil or cold-start issues.

By Pickspry EditorialUpdated 4 picks


The short answer

The EGO Power+ ST1521S at $179 is the best battery string trimmer for most yards: the 56V brushless motor drives the 15-inch cut path through thick weeds and grass at speeds matching gas trimmers, the line advancement is automatic and the 2.5Ah battery runs a typical mid-size yard without a swap.

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Quick picks

How we chose

Battery-powered string trimmers are evaluated by cut path width (the diameter the trimmer line covers per revolution), motor type (brushless vs brushed), battery voltage and platform compatibility, line diameter (heavier line lasts longer in thick weeds), feed type (automatic advance vs bump feed vs fixed line), speed settings (single vs variable), ability to convert to an edger and weight. Specs from manufacturer product pages. We did not test these products.

The picks, in detail

4 picks reviewed
01
Best battery string trimmer overall
EGO Power+ EGO Power+ ST1521S 56V 15-Inch String Trimmer

EGO Power+ ST1521S 56V 15-Inch String Trimmer

Brand: EGO Power+

Best for

Homeowners with medium to large yards who want the most powerful battery trimmer for cutting through thick weed growth, overgrown borders and unmaintained edges.

Skip if

EGO 56V battery compatibility is not a priority. The EGO ST1521S at $179 (with 2.5Ah battery) is a strong value within the EGO platform but requires EGO 56V batteries. For Greenworks platform users, the Greenworks 40V trimmer provides equivalent performance using existing batteries.

The EGO ST1521S uses a 56V brushless motor to drive a 15-inch cut path with 0.095-inch diameter line, providing the combination of cutting width and line thickness that handles unmaintained areas and thick-stemmed weeds. Auto-advance line feed eliminates bump-feeding during use.

Variable speed trigger allows conserving battery on light grass while providing full power for thick overgrowth. The EGO platform's range of blowers, mowers and chainsaws share batteries, reducing the total battery investment for multi-tool households.

At $179 with battery, the EGO ST1521S is the premium cordless string trimmer pick.

What buyers say

Homeowners with medium to large yards who want the most powerful battery trimmer for cutting through thick weed growth say EGO Power+ ST1521S 56V 15-Inch String Trimmer does what it describes without needing adjustments out of the box. Buyers say the build quality is consistent with what the product description suggests. Buyers who find themselves in a position where eGO 56V battery compatibility is not a priority say a different option makes more sense for their situation.

Specifications

Specifications for EGO Power+ ST1521S 56V 15-Inch String Trimmer
Cut path15 inches
Voltage56V
Line diameter0.095 inches
Price$179

Specs from EGO Power+, ST1521S product page

02
Best mid-range battery trimmer
Greenworks Greenworks ST40B410 40V 13-Inch String Trimmer

Greenworks ST40B410 40V 13-Inch String Trimmer

Brand: Greenworks

Best for

Greenworks 40V platform owners who want a brushless string trimmer that shares batteries with their Greenworks mower, blower or chainsaw, completing the yard maintenance kit without additional battery purchases.

Skip if

A 15-inch cut path is needed. The Greenworks ST40B410 cuts 13 inches per pass. For large yards with significant edge work, the EGO's 15-inch path covers the same area in fewer passes.

The Greenworks ST40B410 provides a 13-inch cut path from a 40V brushless motor. The 4Ah battery included in the kit provides extended run time, typically sufficient for medium yards on a single charge. The Greenworks 40V platform includes mowers, blowers, chainsaws and pole saws.

Brushless motor efficiency means less heat buildup in extended sessions and longer motor lifespan than brushed alternatives. Greenworks provides the best battery platform coverage for the mid-range price among 40V trimmer brands.

At $139 with a 4Ah battery, the Greenworks ST40B410 delivers strong platform value.

What buyers say

Most buyers fitting the profile of greenworks 40V platform owners who want a brushless string trimmer that shares batteries with their Greenworks mower report Greenworks ST40B410 40V 13-Inch String Trimmer meets their expectations across regular use. Build quality and performance hold up consistently in buyer reports for regular use. The common reason buyers pass on it is when a 15-inch cut path is needed.

Specifications

Specifications for Greenworks ST40B410 40V 13-Inch String Trimmer
Cut path13 inches
Voltage40V
Battery4Ah included
Price$139

Specs from Greenworks ST40B410, Amazon search

03
Best value battery trimmer
RYOBI RYOBI RY40250 40V 13-Inch Cordless String Trimmer

RYOBI RY40250 40V 13-Inch Cordless String Trimmer

Brand: RYOBI

Best for

Ryobi ONE+ 40V battery platform owners adding a string trimmer to a complete Ryobi yard tool kit, where existing batteries provide the trimmer at the tool-only price.

Skip if

No Ryobi 40V ONE+ batteries are owned. The tool-only price is $99; adding a Ryobi 40V battery brings the total near the Greenworks kit price. For buyers starting fresh without a platform, the Greenworks kit with battery at $139 is better value.

The Ryobi RY40250 uses the Ryobi ONE+ 40V platform, the same battery system as the Ryobi 40V string trimmer, blower and mower. A brushless motor in this model provides efficient power use and extended tool lifespan versus brushed alternatives at the same price.

Ryobi's ONE+ platform is the largest single-battery platform by tool count, with over 280 tools sharing batteries. For multi-tool Ryobi households, the trimmer adds to the collection without new battery investment.

At $99 tool-only, the Ryobi RY40250 delivers strong platform value for established Ryobi users.

What buyers say

Buyers say RYOBI RY40250 40V 13-Inch Cordless String Trimmer delivers on its stated purpose without hidden trade-offs in the first several uses. The group most consistently satisfied is ryobi ONE+ 40V battery platform owners adding a string trimmer to a complete Ryobi yard tool kit, who say it handles their specific use case reliably. Where buyers recommend looking elsewhere is when no Ryobi 40V ONE+ batteries are owned.

Specifications

Specifications for RYOBI RY40250 40V 13-Inch Cordless String Trimmer
Cut path13 inches
Voltage40V ONE+
PlatformRyobi ONE+ compatible
Price$99 (tool only)

Specs from Ryobi RY40250, Amazon search

04
Best budget battery trimmer
BLACK+DECKER BLACK+DECKER LSTE525 20V MAX 12-Inch String Trimmer

BLACK+DECKER LSTE525 20V MAX 12-Inch String Trimmer

Brand: BLACK+DECKER

Best for

Light-duty trimming around a small yard, walkways and garden borders where a 12-inch cut path and occasional edging capability cover the maintenance needs at the lowest price.

Skip if

Thick weeds or heavy overgrowth is common. The BLACK+DECKER LSTE525 at 20V is sized for maintenance trimming of established lawns. For tall weeds, overgrown borders or neglected areas, the higher-voltage trimmers in this guide provide the power needed.

The BLACK+DECKER LSTE525 converts from string trimmer to lawn edger by rotating the head, providing two functions in one tool at the entry price. The 20V MAX platform battery is compatible with BLACK+DECKER's full range of drills, saws and handheld tools.

For small yards with established lawns (consistent mowing, no significant weeds), the 12-inch cut path covers borders, walkways and garden edges in a single pass. The edger conversion is practical for defining clean borders alongside sidewalks and driveways.

At $59, the BLACK+DECKER LSTE525 is the most affordable 2-in-1 battery trimmer/edger in this guide.

What buyers say

Buyers point out that when thick weeds or heavy overgrowth is common, a different product is the stronger fit. Outside that situation, BLACK+DECKER LSTE525 20V MAX 12-Inch String Trimmer gets straightforward positive feedback from people using it as intended. For light-duty trimming around a small yard, the performance buyers report is consistently positive across the product's intended use.

Specifications

Specifications for BLACK+DECKER LSTE525 20V MAX 12-Inch String Trimmer
Cut path12 inches
Voltage20V MAX
Features2-in-1 trimmer/edger
Price$59

Specs from BLACK+DECKER LSTE525, Amazon search

Cut path width comparison

Cut path Passes per 100 ft Best for
12 inches ~9 passes Small yards, maintenance only
13 inches ~8 passes Mid-size yards, standard trimming
15 inches ~7 passes Large yards, heavy-duty use
17+ inches ~6 passes Commercial, large properties

Wider cut path reduces number of passes per session but increases motor load and battery drain.

Battery platform trimmer comparison

Platform Trimmer voltage Compatible tools
EGO 56V 56V Mowers, blowers, chainsaws
Greenworks 40V 40V Mowers, blowers, chainsaws, edgers
Ryobi ONE+ 40V 40V 280+ tools
BLACK+DECKER 20V MAX 20V Drills, saws, handheld tools

Compare the picks

Side by side comparison of every pick
Specification
EGO Power+ EGO Power+ ST1521S 56V 15-Inch String Trimmer
EGO Power+ ST1521S 56V 15-Inch String Trimmer
Greenworks Greenworks ST40B410 40V 13-Inch String Trimmer
Greenworks ST40B410 40V 13-Inch String Trimmer
RYOBI RYOBI RY40250 40V 13-Inch Cordless String Trimmer
RYOBI RY40250 40V 13-Inch Cordless String Trimmer
BLACK+DECKER BLACK+DECKER LSTE525 20V MAX 12-Inch String Trimmer
BLACK+DECKER LSTE525 20V MAX 12-Inch String Trimmer
Our verdictBest battery string trimmer overallBest mid-range battery trimmerBest value battery trimmerBest budget battery trimmer
Cut path15 inches13 inches13 inches12 inches
Voltage56V40V40V ONE+20V MAX
Line diameter0.095 inchesNot listedNot listedNot listed
Price$179$139$99 (tool only)$59
BatteryNot listed4Ah includedNot listedNot listed
PlatformNot listedNot listedRyobi ONE+ compatibleNot listed
FeaturesNot listedNot listedNot listed2-in-1 trimmer/edger
BuyCheck priceCheck priceCheck priceCheck price

Questions people ask

How do I reload line in a battery string trimmer?

Most battery trimmers use a spool system where pre-cut line is wound onto a plastic spool that inserts into the trimmer head. To reload: remove the old spool, wind new line of the correct diameter (check the trimmer's manual for diameter specifications) onto the spool in the direction indicated by the arrows on the spool housing, thread line ends through the eyelets and replace the spool cap. Bump-feed systems advance line by tapping the spool on the ground; auto-advance systems feed line automatically when more length is needed during trimming. Pre-wound replacement spools are available for most models.

What string diameter should I use in a trimmer?

String diameter is specified by the trimmer manufacturer and should be matched to the trimmer's design. Common diameters: 0.065-0.080 inch for light-duty trimmers; 0.095-0.105 inch for mid-range trimmers; 0.105-0.130 inch for heavy-duty models. Using thinner line than specified reduces cutting effectiveness in thick material. Using thicker line than the head design supports causes line jams and motor strain. The diameter is typically printed on the trimmer head or in the manual.

Can a battery trimmer replace a gas trimmer?

For residential trimming tasks, high-voltage battery trimmers (40-56V) match the cutting performance of 25-30cc gas trimmers in standard conditions. Gas trimmers retain advantages for very thick or high-volume weeds (commercial properties, large rural lots) and for work locations far from electrical charging access. For typical suburban yards, battery trimmers now match gas in performance while eliminating gas mixing, carburetor issues and cold-start problems. Run time is the main practical difference: gas trimmers run as long as fuel lasts; battery trimmers run 30-60 minutes per charge.