Black & Decker LST136

Best cordless grass trimmer

  • Lightweight
  • Adjustable power levels
  • Handle swivels for precise edging
  • Limited 15- to 30-minute battery life
  • Not for heavy-duty work

Bottom line

Many Black & Decker cordless string trimmers are top performers, but reviewers say the LST136 is the best. It's the lightest model in our report and experts say it handles well, with an adjustable handle, automatic line feed and a head that swivels into an edger. Runtime on the 36-volt battery varies from 15 to 30 minutes, so the LST136 is best for light-duty landscaping and smaller properties.


Exceptionally quiet. None of the experts evaluating the Black & Decker LST136 measure how noisy it is, but one professional consumer company says it's much quieter than many of the other gas and electric string trimmers they test. A few owners who comment on noise level also say it's very quiet.

The LST136 uses a trigger lock and two-stage starting sequence to prevent the motor from starting with an accidental pull of the trigger. As a light-duty tool, it doesn't launch debris like a beefy gas trimmer.


Adjustable dial balances power and battery. The Black & Decker LST136's Power Command System "puts this cordless a nod above others," says's reviewer. It has six settings to boost cutting power or extend battery runtime, and "the cut quality is superb at any setting," according to Popular Mechanics.

With one light-duty line, the LST136 is best for trimming lawns, experts say. It performs cleanly and quickly, but don't expect it to handle tall grass or thick weeds with just one pass. One user says, "The .065 nylon string advances smoothly and automatically. The 13-inch cutting head swivels in a snap to become an effective lawn edger."

Ease of use

Lightweight, straightforward tool. The Black & Decker LST136 is "much lighter and better balanced than a gas trimmer," says an owner at It's the lightest model in our report, weighing only 7.8 pounds, and has an adjustable handle. Many users who are physically unable to manage a larger trimmer recommend the LST136.

Depending on the power setting, the 36-volt battery lasts about 30 minutes, although one expert test measures runtime at 15 minutes. An on-board electronic display indicates how much battery life is remaining, and the included charger takes 75 minutes to restore the battery.


Higher-end battery. The LST136 is powered by a 36-volt, removable lithium-ion battery (Li-ion). Experts prefer these over nickel-cadmium batteries because they're more powerful and easier to maintain. Li-ion also lasts longer, needing replacement in three to five years. Owners who have used smaller 18- and 24-volt string trimmers say this larger battery is a big improvement.

At, users list high quality and durability as two top advantages of the LST136. Overall, few post comments on breakdowns. Black & Decker's three-year warranty is longer than the average two-year coverage for string trimmers.

Where To Buy
Featured StoresStore RatingNotesTotal Price
ZoroZoro rated 4.65 (97 reviews)97 store reviewsIn Stock. $178.65
Home DepotHome Depot rated 3.58 (4554 reviews)4,554 store reviewsIn Stock. Free Shipping on Over 500K Items!$149.00
Home DepotHome Depot rated 3.58 (4554 reviews)4,554 store reviewsIn Stock. Free Shipping on Over 500K Items!$149.00

Our Sources

1. editors put 21 light-duty cordless string trimmers, including the Black & Decker LST136, through a series of identical tests. They evaluate how well each weed whacker trims a normal lawn, tall grass and unruly weeds. Handling and ease of use factor into the final score.

Review: String Trimmers, Editors of, Not dated

2. Popular Mechanics

Expert testers at Popular Mechanics take a set of electric string trimmers to a Pennsylvania golf course to see how they fare against gas-powered models. They give the LST136 4 stars out of 5, praising the Power Command dial and calling the cut quality "superb at any setting."

Review: Electric String Trimmers: We Test 7 of the Best, Roy Berendsohn, Not dated


With an average rating of 4.4 stars out of 5, the LST136 is one of the highest-rated weed whackers at It's also one of the most popular, with about 300 owner reviews. Users who cut smaller properties, add a backup battery or trim only grass are happiest with its performance.

Review: Black & Decker LST136 13-Inch 36-Volt Lithium Ion Cordless High Performance String Trimmer, Contributors to, As of July 2013


More than 90 percent of the 170-plus reviewers here say they recommend the Black & Decker LST136. Owners call the cordless motor easy to start and handle, and most are pleased with its performance. However, a few complain that battery runtime is too short.

Review: Black & Decker 36-Volt Straight Shaft Cordless String Trimmer, Contributors to, As of July 2013


Here owners say the LST136's Li-ion battery lasts 15 to 30 minutes, depending on the power setting. For most, this is enough to get the job finished. The LST136 gets 4.3 stars out of 5 from more than 70 users, who say quality and durability are the trimmer's two best features.

Review: Black & Decker 36-Volt 13-in Straight Cordless String Trimmer and Edger, Contributors to, As of July 2013

6. names the Black & Decker LST136 as the best cordless string trimmer. It edges out the Core CGT400, Toro 51486, Stihl FSA85 and Worx WG168, partly because of its value and features. "The Power Command dial puts this cordless a nod above the others," the reviewer says.

Review: Black & Decker LST136 36-Volt 13-inch String Trimmer Review, "Dale Y.", June 4, 2013

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