Choosing a 40V string trimmer offers a blend of portability, battery life, and task-focused performance for American lawns. This guide highlights five top options, spanning lightweight designs, 2-in-1 trimmer-eds, and attachments that tackle edging, thick weeds, and fenced borders. Each model emphasizes ease of use, adaptive power, and maintenance-free operation to help you keep lawns neat without gas-powered fuss.
| Product | Brand | Key Features |
|---|---|---|
| Greenworks 40V 12″ Cordless String Trimmer | Greenworks | 12″ cutting path, auto feed, variable speed |
| Black+Decker 40V MAX String Trimmer & Edger Kit | BLACK+DECKER | 2-in-1 trimmer/edger, battery included, high-torque drive |
| Greenworks 40V 12-Inch Cordless String Trimmer (BST4000) | Greenworks | 12″ cut, auto feed, variable speed |
| RYOBI 40V 15 in. Expand-It Cordless Trimmer | RYOBI | Attachment-ready, 13″–15″ cut width, versatile |
| Greenworks 40V 13″ Cordless String Trimmer/Edger (Gen 2) | Greenworks | 2-in-1 trimmer/edger, 90° head rotate, battery included |
Greenworks 40V 12″ Cordless String Trimmer
The Greenworks 40V 12″ cordless string trimmer features a 12-inch cutting path with a 0.065″ dual line, designed for clean and consistent edging around lawns and sidewalks. Its auto feed line system reduces the need to bump feed, helping users maintain steady trimming sessions. A variable speed control lets you dial in power for edging or lighter tasks, balancing performance with battery efficiency. Lightweight construction supports easier handling for prolonged use, and a 3-year warranty adds long-term value.
Black+Decker 40V MAX String Trimmer & Edger Kit
This Black+Decker model provides a strong 40V MAX lithium battery with an accessible state-of-charge indicator. It offers a high-torque transmission for efficient cutting and quickly converts from trimmer to edger, enabling clean borders and pathways. The kit includes a battery and charger, simplifying setup. The design emphasizes quick transitions between trimming and edging tasks, helping maintain precise boundaries in lawns and garden beds.
Greenworks 40V 12-Inch Cordless String Trimmer (BST4000)
The BST4000 model runs on 40V and maintains a 12-inch cutting path with a .065″ line and an auto feed head for quick line advancement. The variable speed trigger enables on-the-fly adjustments to handle dense weeds or delicate edging around landscaping. Its compatibility with Greenworks’ 40V ecosystem makes battery sharing practical, and the unit is designed for cool operation during extended trimming sessions in varying weather conditions.
RYOBI 40V 15 in Expand-It Trimmer
The Expand-It system from Ryobi adds attachment versatility for a broader set of yard tasks. This trimmer uses a 40V battery (sold separately) and supports adjustable 13″ to 15″ cutting swaths. The attachment capability enables conversion to a variety of tools, expanding yard care options beyond trimming alone. For larger yards or complex landscapes, the Expand-It platform can offer extended reach and task flexibility.
Greenworks 40V 13″ Cordless Trimmer/Edger Gen 2
Greenworks Gen 2 40V 13″ trim/edger combo offers a 2-in-1 design with a 90° pivoting head. The push-button conversion between trimming and edging modes supports efficient workflow around flower beds and hardscape edges. The included 20 blades and brush cutter upgrade option enhance capability for tougher growth, while a single battery powers multiple tools in the Greenworks ecosystem, simplifying storage and charging routines.
Buying Guide
Key considerations when selecting a 40V string trimmer include cutting width, line feed mechanism, weight, and battery compatibility. A wider cutting path (11–13 inches) speeds up edging around lawns and driveways, but may require more power for thick weeds. Auto-feed lines reduce manual bumping, preserving momentum during longer trimming sessions, while variable speed triggers allow users to dial in power for delicate trimming near shrubs and ornamentals.
Battery life and ecosystem compatibility closely affect long-term value. Models within the Greenworks and Ryobi families often share batteries, enabling a single charged pack to power multiple tools. If you anticipate frequent edging or occasional brush cutting, consider a model with a 2-in-1 design or a robust attachment system, such as Expand-It, to expand versatility without purchasing multiple devices.
Weight and ergonomics are critical for comfort during extended tasks. Look for adjustable handles, rotating heads, and balanced centers of gravity to minimize fatigue. A model with a quick conversion between trimming and edging tasks can improve efficiency, especially along lawn borders, sidewalks, and fencing lines.
Maintenance and support matter for uptime. A model with straightforward line advancement, reliable warranty coverage, and accessible replacement parts reduces downtime. For homeowners with larger properties, selecting a system with fast, compatible batteries and a broad selection of compatible tools ensures better lifecycle value.
In summary, the best 40V string trimmer choice depends on yard size, terrain, and preferred workflow. If you want a compact, affordable entry, the Greenworks 12″ models provide balanced performance with auto-feed. For 2-in-1 versatility with ready-made battery bundles, BLACK+DECKER and Greenworks Gen 2 options are strong bets. For broader attachment support and expansion, Ryobi Expand-It or a higher-capacity Greenworks kit can be advantageous, especially for edging and heavy weed control.