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A 40V string trimmer is the sweet spot for many homeowners who need cordless power without the hassles of gas. You want enough runtime and line speed to handle thick grass, weeds, and occasional brush, plus a tool that is light enough for longer trimming sessions. This guide summarizes six shortlisted 40V string trimmers that meet those needs and explains the real-world tradeoffs. We evaluated each option on cutting performance, battery life, ergonomics, and durability so you can pick the best fit for your yard and mowing routine. Read on to see the features that matter most and which specs to prioritize.
Top Picks at a Glance
| Best Overall The best all-around choice for most situations | Greenworks 40V 16 in String Trimmer & 550 CFM Blower Combo (4.0 Ah Battery) |  |
| Best Quality Built to a higher standard if you want something more solid | SKIL PWR CORE 40 Brushless 16-Inch Cordless Multi-Head String Trimmer Kit (4.0Ah Battery) |  |
| Best Value The sweet spot between price and what you get | BLACK+DECKER 40V MAX 13 in Cordless String Trimmer and Edger (LST136) with Battery and Charger |  |
| Best Budget The cheapest option that still gets the job done reliably | BLACK+DECKER 40V MAX String Trimmer and Lawn Edger (LST136B) – Bare Tool |  |
| Highest Rated A top-rated pick with lots of positive feedback | Makita GRU01Z 40V Max XGT Brushless 15" Cordless String Trimmer (Tool Only) |  |
| Most Popular A crowd favorite that many people choose with confidence | Greenworks G-MAX 40V 12" Cordless String Trimmer and 390 CFM Blower Combo (2.0Ah) |  |
Greenworks 40V 16 in String Trimmer & 550 CFM Blower Combo (4.0 Ah Battery)
| Power Source | Battery Powered |
|---|---|
| Cutting width | 16 inches |
| Speed | 6000 rpm |
| Battery Average Life | 50 minutes |
| Blower airflow | 550 CFM |
This Greenworks 40V combo bundles a 16-inch brushless string trimmer and a 550 CFM blower with a 4.0 Ah lithium-ion battery for a flexible, gas-free yard-care kit. The brushless motor gives stronger, quieter performance and longer run-time than brushed designs, and the trimmer is attachment-capable if you want to expand to pole saws or hedge tools later. In practice the 16-inch cutting width is well suited to trimming and edging around sidewalks, flower beds, and fence lines while the blower clears patios, driveways, and walkways of leaves and debris quickly. The included battery delivers fade-free power and is part of Greenworks 40V platform so batteries swap between other tools in the line. Because it is cordless, it starts instantly and needs little maintenance compared with gas equipment, though runtime depends on battery capacity and heavy-duty jobs may require a spare battery for larger yards. The combo is a solid choice for homeowners who want a quieter, lower-maintenance alternative to gas with the convenience of a matched blower and trimmer.
Best for: Homeowners who want a reliable, low-maintenance cordless alternative to gas for routine trimming, edging, and debris cleanup on small to medium yards and value a matched trimmer/blower kit.
Less Ideal for: Users with large properties over half an acre or professionals who need extended runtime and heavier-duty cutting power should consider higher-voltage or commercial-grade equipment.
- Brushless motor for stronger power, longer life, and improved runtime
- Combo kit includes both 16-inch trimmer and 550 CFM blower for common yard tasks
- Compatible 40V battery platform allows swapping batteries with other Greenworks tools
- Maintenance-free operation with no gas, oil, or tune-ups and instant electric start
- Single included 4.0 Ah battery may limit continuous runtime on larger properties
Verdict: A practical, low-maintenance 40V combo that pairs a capable 16-inch brushless trimmer with a 550 CFM blower for most homeowners' routine yard work.
SKIL PWR CORE 40 Brushless 16-Inch Cordless Multi-Head String Trimmer Kit (4.0Ah Battery)
| Power Source | Battery Powered |
|---|---|
| Cutting width | 16 inches |
| Speed | 6000 rpm |
| Number of Batteries | 1 Lithium Ion (included) |
The SKIL PWR CORE 40 brushless trimmer is designed for homeowners who want near-professional cutting performance without gas. Its digital brushless motor and two-speed selector give strong, efficient power for tackling tall grass and thick weeds while preserving battery life. The kit includes a 4.0Ah PWR CORE battery and Auto PWR JUMP charger for faster recharge and longer runtime than typical 40V batteries, and the dual-line bump feed plus twist-load head make line changes quick and frustration-free. The power head is attachment-ready, so you can expand to other yard tools on the same battery platform. Practical limitations are that this is a one-battery kit so very large properties may need a spare battery for uninterrupted work, and while the 16-inch swath is efficient for most lawns it is narrower than some commercial trimmers. For performance-minded buyers who prefer cordless convenience and modular tool systems, this trimmer balances power, runtime, and easy maintenance.
Best for: Buyers who prioritize cutting performance and runtime in a cordless trimmer and who want a modular 40V platform they can expand with other attachments.
Less Ideal for: Large acreage owners who need long continuous runtime out of the box or commercial users who require wider cutting swaths and heavier-duty commercial equipment.
- Brushless digital motor for efficient, higher-performance cutting and longer tool life
- Includes 4.0Ah PWR CORE battery and fast Auto PWR JUMP charging for improved runtime
- Dual-line bump feed and twist-load head for fast, tool-free line replacement
- Attachment-ready power head lets you swap on other SKIL 40V tools for broader yard work
- Kit includes a single battery so continuous work on large properties may require buying an extra battery
- 16-inch cutting width is narrower than some professional-grade trimmers
Verdict: A high-performance 40V brushless trimmer that delivers strong cordless cutting and fast charging on a modular battery platform.
BLACK+DECKER 40V MAX 13 in Cordless String Trimmer and Edger (LST136) with Battery and Charger
| Power Source | Battery Powered |
|---|---|
| Cutting width | 13 inches |
| Speed | 8500 rpm |
| Number of Batteries | 1 Lithium Ion (included) |
The BLACK+DECKER LST136 is a battery-powered 13-inch string trimmer that doubles as an edger for common yard maintenance around a typical home. It is powered by a 40V Max lithium-ion battery with a state-of-charge indicator and a fast charger so you can gauge runtime and restore power in roughly two hours. The POWERDRIVE transmission and 8500 rpm top speed give it enough punch to cut through thicker weeds, while the PowerCommand dial lets you prioritize torque or runtime depending on the job. The Automatic Feed Spool reduces interruptions by advancing line as needed without bumping. Practical touches like an adjustable telescoping shaft, soft-grip handle, and included auxiliary handle improve comfort for longer sessions. Converting to an edger is quick, making boundary cleanup easier after trimming. Limitations are typical of battery trimmers: runtime depends on battery capacity and heavy, continuous use will need recharge or a spare battery, and it is best for homeowner yards rather than commercial heavy-duty jobs.
Best for: Homeowners who want a versatile, cordless trimmer that handles routine lawn edging and light-to-medium weed cutting with user-friendly controls and easy conversion between trimmer and edger.
Less Ideal for: People who need a high-hour commercial tool or who regularly tackle very large properties where long continuous runtime and industrial power are required.
- Includes 40V Max lithium-ion battery with state-of-charge indicator and fast charger for quick turnaround
- PowerCommand dial to choose higher power or longer runtime for different yard tasks
- Automatic Feed Spool supplies line as needed without bumping
- Converts quickly from trimmer to edger for versatile edge cleanup
- Adjustable telescoping shaft and soft-grip handle improve comfort during use
- Battery runtime is limited for extended heavy-duty work and may require a spare battery
- Not intended for commercial or continuous professional use
Verdict: A comfortable, easy-to-use cordless trimmer/edger kit that balances power and convenience for typical homeowner yard maintenance.
BLACK+DECKER 40V MAX String Trimmer and Lawn Edger (LST136B) – Bare Tool
| Power Source | Battery Powered |
|---|---|
| Cutting width | 13 inches |
| Speed | 1400 rpm |
| Number of Batteries | 1 Lithium Ion batteries required. |
The BLACK+DECKER LST136B is a battery-powered 13-inch string trimmer that doubles as a quick-convert edger for tidying borders. It pairs with a 40V MAX lithium battery (not included) and uses a POWERDRIVE transmission plus an Automatic Feed Spool so you can cut through common lawn grasses and light weeds with uninterrupted line feed. A power command dial lets you dial up torque for thicker patches or conserve battery for longer runs. The tool ships as a bare unit with a guard, auxiliary handle, and AF-100 spool so you can drop it into an existing 40V battery ecosystem or choose your preferred battery and charger. Practical benefits include low vibration, simple edging conversion, and the convenience of cordless operation without gas. Important limitations are that the battery and charger are not included and runtime depends on which 40V pack you pair it with, so you may need to invest in a compatible battery to match heavier workloads.
Best for: Homeowners who want a compact, no-gas trimmer that can plug into a 40V battery platform and prioritize ease of use and low operating cost over peak commercial power.
Less Ideal for: Large properties or heavy-duty brush clearing where run-time and raw power are the top priorities and a dedicated gas or higher-voltage commercial unit would be better.
- Converts quickly between trimmer and edger for versatile yard cleanup
- Automatic Feed Spool reduces downtime by keeping line fed during use
- Power command dial provides adjustable power for thicker growth or longer runtime
- Compatible with 40V MAX batteries so it can join an existing battery system
- Includes guard and auxiliary handle for safer, more comfortable operation
- Sold as a bare tool so battery and charger must be purchased separately
- 13-inch cutting width may require more passes on very large properties
Verdict: A practical, wallet-friendly 40V trimmer-and-edger that fits homeowners who already own or plan to invest in BLACK+DECKER 40V batteries.
Makita GRU01Z 40V Max XGT Brushless 15" Cordless String Trimmer (Tool Only)
| Power Source | Battery Powered |
|---|---|
| Cutting width | 15 inches |
| Speed | 6500 rpm |
The Makita GRU01Z is a pro-grade 40V max XGT string trimmer built to replace gas units on demanding jobs. It uses a Makita outer-rotor brushless motor and digital XGT communication to keep power high under load, while Automatic Torque Drive Technology shifts RPM between 3,500 and 6,500 to balance run time and cutting force. Typical use will be heavy trimming around fence lines, driveways, and job-site cleanup where a 15" cutting swath speeds work. The Rapid Load bump-and-feed head makes line changes quick, a reverse-rotation function clears entangled material, and IPX4 and XPT protections help resist dust and water on rough sites. As a tool-only unit it requires XGT batteries and a charger, which lets teams mix batteries across compatible gear but adds cost if you do not already own the system. Expect strong, gas-like performance and robust build quality paired with the convenience and lower noise of cordless operation.
Best for: Contractors or serious homeowners who prioritize consistent, gas-like cutting power and durable construction for frequent heavy trimming.
Less Ideal for: Casual users with only light trimming needs or first-time buyers who do not want to invest in the XGT battery platform.
- High-power outer-rotor brushless motor and digital XGT communication for sustained performance under heavy load
- Automatic Torque Drive Technology with three speed settings to match power and run time to the task
- Rapid Load bump-and-feed head and reverse rotation for fast line changes and clearing jams
- IPX4-rated construction and XPT protection for improved dust and water resistance on job sites
- Sold as tool-only so battery and charger are required and sold separately
- 15" cutting width is large but may be less maneuverable in very tight ornamental beds
Verdict: Choose the Makita GRU01Z if you need a durable, gas-replacing 40V trimmer that delivers sustained power and professional features on demanding jobs.
Greenworks G-MAX 40V 12" Cordless String Trimmer and 390 CFM Blower Combo (2.0Ah)
| Power Source | Battery Powered |
|---|---|
| Cutting width | 12 inches |
| Speed | 7500 rpm |
| Number of Batteries | 1 Lithium Ion (included) |
| Battery Average Life | 2 hours |
This Greenworks combo pairs a 12-inch, .065" auto-feed trimmer with a 390 CFM blower and a single 40V 2.0Ah battery to tackle common small-yard tasks without gas or cords. The trimmer’s auto-feed dual-line head and 7500 rpm brushless motor make edging and cutting 1-inch weeds along fences and walkways quick and predictable, while the blower’s cruise-control mode sustains high airflow to clear wet leaves from driveways and patios. Because the trimmer and blower run off the same 40V ecosystem, swapping between tasks is fast and the included battery recharges in about 60 minutes. The kit is noticeably lighter and quieter than equivalent gas tools which reduces fatigue during longer sessions and lets you work earlier in the morning. Expect shorter run times than larger battery platforms under heavy continuous loads, and very dense brush will stress the 2.0Ah pack more quickly. Overall this is a practical, low-maintenance combo for homeowners who want strong day-to-day performance in a compact, cordless package.
Best for: Homeowners with small to medium yards who prioritize strong, gas-free performance and quick switching between trimming and blowing for tidy edges and hard surfaces.
Less Ideal for: Landscapers or users who need long continuous runtime or want to tackle thick brush and heavy-duty clearing on large properties.
- Auto-feed dual-line 12" trimmer head reduces downtime for line changes and keeps cutting consistent
- Brushless motor and 7500 rpm deliver strong cutting power for typical yard weeds
- Shared 40V battery lets you switch between trimmer and blower without extra batteries
- 390 CFM blower with cruise control clears wet leaves and debris efficiently
- Lightweight and quieter than gas equivalents, reducing fatigue and neighborhood disturbance
- 2.0Ah battery provides limited continuous runtime under heavy use compared with larger-capacity packs
- Not intended for heavy brush cutting or professional-scale workloads
Verdict: A compact, performance-focused cordless trimmer and blower combo that delivers strong everyday cutting and blowing for small yards while eliminating gas and cord hassles.
Choosing the Right 40V String Trimmer: Key Factors to Consider
Cutting Power and Line Speed
Cutting power determines how cleanly a trimmer slices thick grass and light brush. Higher sustained RPMs make a big difference when you hit dense patches; a trimmer that stalls or slows under load forces you to make multiple passes and extends job time. Consider how the motor delivers torque at low speeds as well as top-end revs, since torque helps maintain line momentum through tough areas.
Line speed also affects the quality of the cut and how easily you can edge. Wider cutting swaths reduce time spent trimming, but only if the motor and battery can keep the line turning fast enough to avoid ragged results.
Battery Capacity and Real-World Runtime
Battery voltage is only part of the story. Amp-hour capacity and the battery chemistry determine how long a 40V pack will power a trimmer under realistic loads. Manufacturers often quote runtime for light trimming; expect shorter runtimes when cutting thick or damp grass.
Also consider recharge time and whether the battery platform is shared with other tools in your kit. A fast-charge option or a second battery can change how you use the trimmer during longer sessions. Thermal management matters too; batteries that overheat will throttle and reduce usable runtime.
Ergonomics and Handling
Comfort affects how long you can trim without fatigue. Look at weight distribution between motor and battery, shaft length adjustability, and whether the handle position can be changed for edging or overhead work. A well-balanced trimmer feels lighter in use and reduces shoulder and lower-back strain.
Controls should be intuitive and reachable while wearing gloves. Variable speed triggers or dedicated boost modes let you match power delivery to the task, saving battery life for lighter jobs and giving burst power for thick spots.
Head Design and Line Feed Practicality
How the trimmer feeds and stores line influences downtime and frustration. Bump-feed heads are common and fast to reload, but some designs jam or require awkward threading. Tap-and-go heads are convenient, while fixed-line or dual-line heads may offer cleaner cuts at the cost of more frequent reloading.
Also check spool capacity and the ability to use twisted or pre-cut line if you prefer. A guard that sheds debris and an easily reachable head make maintenance in the field much simpler.
Durability and Weather Resistance
Outdoor tools face wet grass, dirt, and occasional impacts. Materials, seals around the motor and battery area, and the robustness of the gearbox determine how long a trimmer will last in regular garden use. Metal gearheads typically stand up better to heavy-duty use than plastic-only gear trains.
Look for corrosion-resistant fasteners, replaceable guards, and easily sourced replacement parts. A trimmer that tolerates occasional exposure without rapid corrosion or drive wear will save time and cost in the long run.
When a 40V Trimmer Is the Right Choice
Choose a 40V string trimmer when you need cordless power that tackles medium to large yards without the constant maintenance of a gas engine. These units generally deliver more torque and longer run time than lower-voltage models, making them suitable for thick turf, overgrown edges, and light brush clearing.
A 40V unit also pairs well with daily yard workflows where quick starts, lower vibration, and cleaner operation are priorities. If you have other 40V garden tools, sharing batteries can streamline charging and extend effective runtime across tasks.
- Best for medium to large yards with mixed grass and weeds
- Suitable for occasional brush and dense patches
- Good match for gardeners who prefer low maintenance and quiet operation
Sizing Your Trimmer to Your Yard
Match cutting head width and battery capacity to how you maintain your landscape. A wider head cuts more area per pass but demands more from the motor and battery. For lots with long runs along fences and beds, choose a setup with larger capacity batteries or plan for a spare pack.
If your property has lots of tight corners, steps, or ornate beds, prioritize maneuverability and a narrower head that lets you trim close to obstacles without overreaching.
- Wider cutting swathes speed work on open lawn edges
- Narrower heads improve control around plantings and furniture
- Consider having a spare battery for extended sessions
Maintenance Tips to Extend Service Life
Regular maintenance keeps a cordless trimmer performing season after season. Clean the guard and head after each use to prevent buildup that can unbalance the cutting system. Inspect the shaft and handle mounts for looseness and tighten fasteners as required.
Replace spool line at the first sign of fraying. If you use a battery platform across tools, follow manufacturer guidance on storage charge and temperature to preserve pack health.
- Clean debris from the head and guard after each use
- Check fasteners and replace worn line promptly
- Store batteries at recommended charge level and temperature
Safe Trimming Practices
Always wear eye and ear protection, sturdy shoes, and long pants when operating a string trimmer. Clear the work area of rocks, toys, and debris first to prevent projectiles and damage to the head.
Work from areas of low height to high height so cuttings fall away from finished areas. When edging, use slow, controlled passes to avoid gouging turf or disturbing plant roots.
- Wear eye protection and sturdy footwear
- Remove debris from the trim zone before starting
- Use controlled passes to avoid scalping or plant damage
Battery Care for Peak Performance
Avoid storing batteries fully depleted or at extreme temperatures. Lithium packs perform best when stored in a cool, dry place at about half charge for long-term storage. Rotate batteries if you have more than one to prevent a single pack from being cycled heavily while others sit idle.
During heavy jobs, allow batteries to cool between charges to prevent thermal throttling. If a tool supports a fast-charge option, factor that into how you plan work across the yard.
- Store batteries cool and at moderate charge for long-term life
- Rotate multiple packs to equalize cycle wear
- Let packs cool between heavy runs to preserve output
How We Chose the Best 40V String Trimmer
Our selection process focused on features and real-garden performance that matter for 40V string trimmers. We prioritized durable cutting systems that maintain line speed under load, battery systems with realistic runtime and fast recharge characteristics, and motor cooling or gearing that reduce heat and wear during heavy use. Ergonomics and handling were evaluated for balance, shaft length, and head adjustability to reduce fatigue during edging and slope work. We also looked at head and spool designs for quick line changes and whether guards and bump-feed systems resist clogging with wet grass. Excluded were models that rely on smaller voltage platforms or that require proprietary accessories with limited availability. We also excluded trimmers that are clearly underspecified for medium to large yards or those with no meaningful thermal management. Final choices reflect a balance of cutting efficiency, battery runtime, build durability, ease of use, and maintenance convenience.
FAQ
How long will a 40V battery run when trimming a typical lawn?
Runtime varies with line width, grass density, and throttle use. For moderate trimming expect between 30 and 60 minutes per charge on a mid-capacity pack; heavy, continuous cutting reduces that significantly. Using a second battery or lower speed settings can extend practical working time.
Can 40V trimmers handle light brush and thick weeds?
Many 40V trimmers have enough torque for light brush and thick weeds, especially with a heavy-duty line or a slower, more powerful mode. However, very woody stems or dense saplings may still require a brush cutter or pruning tool designed for that work.
Is a straight shaft or curved shaft better for yard work?
Straight shafts provide better reach and are easier to use on slopes and around beds while often offering better balance for two-handed work. Curved shafts can be lighter and more maneuverable for close-in trimming. Choose based on how much reach and overhead work you expect to do.
How do I reduce vibration and fatigue during long trimming sessions?
Look for models with balanced motor placement, cushioned handles, and adjustable harness or strap attachment points. Shorten session lengths or use a second battery so you can pause and rest. Practicing proper stance and alternating hands slightly can also reduce muscle strain.
What maintenance keeps a 40V trimmer working reliably year after year?
Regularly clean the head and guard, inspect and replace the cutting line, tighten loose fasteners, and follow battery storage guidance. If the trimmer has a gearhead, check it for wear and replace worn parts to prevent sudden failure.
Final Verdict
Focus your decision on the tasks you do most often. Prioritize cutting power and battery capacity if you maintain larger areas or frequently hit dense grass. If your yard has many obstacles, prioritize balance, handle adjustability, and a head that is easy to service. Tradeoffs are unavoidable: wider cutting paths save time but demand more battery capacity. Choose the configuration that matches how long you want to work between charges and how comfortable you need the tool to be for extended sessions.
