--- title: "I Tested The Bosch GRT18V-40 String Trimmer For 3 Months. My Weeds Didn’t Stand A Chance" date: "2026-09-10" modified: "2026-09-10" authors: - name: "Mark Wolfe" job_title: "Staff Writer" link: "https://www.bobvila.com/authors/mark-wolfe.md" url: "https://www.bobvila.com/reviews/bosch-grt18v-brushless-string-trimmer-review/" categories: - "Lawn & Garden" - "Lawn Care" - "Lawn, Garden & Pool" - "Reviews" tags: - "SPR" --- # I Tested The Bosch GRT18V-40 String Trimmer For 3 Months. My Weeds Didn’t Stand A Chance ![Bosch string trimmer and leaf blower]() *Photo: Mark Wolfe for BobVIla.com* The professional-grade Bosch GRT18V-40 brushless string trimmer came out in early 2026, and I got a chance to try one soon thereafter. Recent generations of battery-powered landscaping tools have begun to match or surpass the raw power of their gas-fueled counterparts. Now, more design focus has shifted toward improving the overall operator experience. I wanted to find out whether or not the feature upgrades really moved the needle. The GRT18V-40 is a powerful brushless string trimmer designed for heavy-duty [yard work](). It delivers working power equivalent to a 600-watt corded electric motor, at speeds up to 5,300 RPM. The included trimmer head is compatible with .080 and .095 trimmer line sizes and cuts a 16-inch swath. With the included battery installed, it weighs in at about 15 pounds. ## - **Powerful performance.** The Bosch GRT18V-40 delivers cutting power equivalent to a 600-watt motor, outperforming a 25cc gas trimmer in heavy weeds. - **Extended battery life.** New tabless batteries offer up to 90 minutes of light trimming per charge, enhancing runtime and output. - **Innovative features.** Includes an anti-tangle system, variable throttle, and dual-function grips for improved user experience. - **Weight balance issue.** At 15 pounds, the trimmer is front-heavy, lacking a shoulder strap for better weight distribution. **Bottom line:** The Bosch GRT18V-40 is a powerful, battery-operated string trimmer ideal for midsize to large properties, offering strong performance and innovative features despite some balance concerns. ## Performance and Runtime The kit I received came with the new Bosch Expert 18-volt 8-amp-hour tabless battery and charger. These new tabless batteries work with the entire AMPShare ecosystem, offering more power and runtime than earlier battery technologies. For this release, Bosch rolled out an exclusive anti-tangle system to improve cutting performance and reduce downtime when working through heavy weeds. The trimmer also features an upgraded variable throttle and adjustable dual-function (trimming/edging) hand grips. I tested the [GRT18V-40]() for 3 months in my own yard. I used it for the normal trimming that accompanies weekly mowing, edging along the driveway and curb, and for cutting back high, weedy areas at the back of the property. My overall impression was that it was great. It actually offered more cutting power in the tall weeds than my 25cc 2-cycle trimmer. The shortest runtime I clocked was 23 minutes per charge while running it at full power nonstop in heavy weeds. I got over 90 minutes of average/light trimming time per charge. - ![]() *Photo: Mark Wolfe for BobVila.com* - ![Bosch string trimmer adjustable handle]() *Photo: Mark Wolfe for BobVila.com* - ![Bosch string trimmer battery]() *Photo: Mark Wolfe for BobVila.com* - ![Bosch string trimmer head]() *Photo: Mark Wolfe for BobVila.com* - ![Bosch string trimmer motor]() *Photo: Mark Wolfe for BobVila.com* - ![Bosch string trimmer and leaf blower 1]() *Photo: Mark Wolfe for BobVila.com* [][][] ## Limitations and Final Thoughts My only negative impression was of the weight balance. At roughly 15 pounds with the battery equipped, it weighs about the same as my gas trimmer, but the motor mounted above the trimmer head creates a front-heavy situation. While that’s fine for heavy growth, it makes using it more tiring than necessary for average trimming conditions. You can correct the balance somewhat by moving the loop handle down the shaft, but not perfectly. Also, the kit did not include a shoulder strap to help transfer the weight, and it doesn’t look like Bosch offers one. The [Bosch GRT18V-40 brushless string trimmer]() has a lot to offer folks who own properties that are midsize or larger. Most notably, it features strong, pro-quality trimming power with ample runtime per charge. I thought the new throttle trigger offered exceptional control through the full speed range. The batteries were noticeably better in terms of runtime and output than prior Bosch batteries I’ve used. If you’re looking for a new battery string trimmer, this one offers strong performance at a fair price. ## Author Mark Wolfe is a BobVila.com staff writer with an extensive background in the horticulture industry. Since 2020, he has contributed numerous gardening and home improvement articles, along with a variety of tool and product reviews.