DeWalt 20V MAX 13 in. Cordless String Trimmer Kit (includes 4 Ah battery & charger)

The quick take

After a month of weekend yard work with DeWalt’s 20V trimmer, I came away impressed by its cutting torque for a compact, 13-inch machine, and frustrated by the stock bump-feed head. Paired with a 4.0Ah battery, it’s a quiet, capable trimmer for routine residential use, especially if you’re already on DeWalt’s 20V platform. Push it beyond lawn edges and regular grass—into dense weeds or long-overdue growth—and you can expect shorter runtime and some thermal protection cutouts. Swap the head and line, set the grip where it fits your stance, and it becomes a solid, no-fuss yard companion.

Setup and first impressions

Out of the box, assembly is straightforward: attach the guard, adjust the front handle, click in a battery, and go. The straight shaft is slim, with a modest amount of flex if you lean on it, but it’s not flimsy. At about 8.5 lb bare (roughly 9.5–10 lb with a 4Ah pack), it’s lighter than most gas models and easy to store.

Controls are simple and work well: a variable-speed trigger, a two-position Hi/Lo speed switch on the handle, and a lock-off. I like the speed switch’s placement—easy to thumb while lining up a cut—but the lock-off is small and stiff with gloves. You learn the motion after a few sessions.

Build-wise, it feels like a homeowner tool designed to be tossed in the garage, not a contractor’s beater. That’s fair given the class. Just don’t use the shaft as a lever around rocks or edging pavers; it’s not meant to pry.

Ergonomics and balance

Balance is middling out of the box but improves a lot with handle placement. I shifted the front handle slightly forward and angled it so my forearm lines up with the shaft. That reduced wrist fatigue and made edging more controlled. If you’re under 5'8", you’ll likely keep the handle closer; taller users will want it further forward. A simple shoulder strap (not included) makes longer sessions much easier and keeps the nose from dipping when the battery is nearly empty.

Vibration is controlled for a dual-line head. Noise is modest—neighbors won’t glare at you for morning trimming.

Power and cutting performance

This trimmer’s gear-drive transmission gives it a welcome boost in torque. In Lo, it trims turf edges and light weeds without showering your legs in clippings. In Hi, it keeps RPM up through thicker patches where many compact 20V units bog down. I cleared fence-line ryegrass that had gotten ahead of me and was pleasantly surprised at how consistently it maintained speed—until I hit clusters of fibrous weeds where I had to slow my feed rate and keep the line at full length to avoid “whipping” instead of cutting.

A few tips that made the difference:
- Run Hi only when you need it. Lo cuts cleaner in typical grass with less feathering.
- Keep your line at the guard’s cutter length. Too short and you’ll tear instead of slice.
- Use a fresh, round .080 in line (or a premium .080–.090 if the head accepts it). Stale, brittle line dramatically worsens cut quality.

Edging is manageable with the straight shaft. Rotating the head 90 degrees isn’t built-in, so you’ll hold it sideways; light, steady passes beat one aggressive pass.

Runtime and batteries

The kit’s 4.0Ah battery is the right starting point. In Lo, maintaining garden edges and around trees, I consistently saw 25–35 minutes of continuous trigger time. Mixed use with Hi for fence lines and weedier corners cut that to around 18–25 minutes. On an easy day, I could stretch a full small-suburban yard without a swap; on a neglected week, I needed a second pack.

Expectations matter here:
- Light trimming, Lo speed: ~30 minutes on 4.0Ah
- Mixed trimming with bursts in Hi: ~20–25 minutes
- Heavy, continuous Hi in dense growth: 10–15 minutes and potential thermal pauses

If you own 5.0Ah or 6.0Ah packs, runtime scales proportionally, but weight creeps up. I prefer two 4.0Ah packs over one large brick for balance.

The head and line experience

Here’s where my patience wore thin. The included dual-line bump-feed head works, but reloading it is fiddly, and in gritty conditions it was inconsistent feeding line—sometimes stingy, sometimes spitting too much after a few bumps. On my third reload I swapped the factory head for DeWalt’s QuickLoad replacement (DW01DT995). That change transformed the experience. I can reload in under a minute without pulling the head apart, and feeding became predictable.

Line choice also matters. The bundled .080 in line cuts cleanly when fresh, but it wore quickly against chain-link and hardscape. A premium-grade .080 lasted longer and cut more precisely. I’ve also run a flexible .090 in a universal head for rough areas; it improves durability and cut “bite,” but it slightly reduces runtime and isn’t necessary for routine turf. Stick to the diameter your head supports.

One small tweak that helps: touch up the little cutter blade on the guard with a few strokes from a file. A sharp cutter trims line crisply, keeping the swath consistent and the motor from laboring.

Heat management and protection

Like most compact cordless trimmers, this one will protect itself if you work it flat-out in hot weather. I triggered a couple of thermal timeouts after prolonged Hi-speed cutting in thigh-high, wet weeds. The motor stopped, and after a minute or two it resumed. That’s normal behavior, but it’s a sign you’re pushing the boundaries. If this is your routine workload, you’re in the wrong class—step up to a higher-voltage or larger-deck model.

Reliability and service

Over my test period I didn’t experience failures, but I’ll note two things. First, keep the head clean; abrasive dust can make any bump mechanism misbehave and increase motor load. Second, this model carries a 3-year limited warranty, 1-year free service, and 90-day money-back guarantee. Register the tool and keep your proof of purchase. If your unit shows early, abnormal behavior—very short runtime, cutting out under light load—treat that as a defect and use the return window or warranty rather than fighting it.

What it’s great at

• Regular lawn-edge maintenance, bed borders, around posts and AC units
• Homeowners already invested in DeWalt 20V packs
• Users who value a lighter, low-noise tool over maximum cutting swath
• Anyone willing to upgrade the head for easier line management

Where it struggles

• Long, dense, or woody weeds that require sustained Hi-speed cutting
• Users who expect gas-like endurance from a single compact battery
• People who dislike bump-feed heads and won’t consider a head upgrade
• Pros or acreage owners needing a 15–17 in swath and all-day runtime

Practical tips to get the most from it

• Set the front handle to keep your wrist straight; it reduces fatigue and improves cut quality.
• Start in Lo; shift to Hi only when RPM sag becomes noticeable.
• Keep the line fresh and at full cutter length; re-spool before it gets too short.
• Consider the QuickLoad head; it’s a worthwhile, low-cost upgrade.
• Carry a second battery on bigger jobs, especially in hot weather.

The bottom line

The DeWalt 20V trimmer is a capable, compact yard tool with better-than-expected torque for its size, sensible controls, and homeowner-friendly manners. Its Achilles’ heel is the stock bump head, which is serviceable but undermines an otherwise smooth experience. With a quick head upgrade and good line, it cuts cleanly, feels more premium than the price suggests, and fits neatly into a 20V toolkit.

Recommendation: I recommend this trimmer for homeowners who already own DeWalt 20V batteries and need a reliable, lightweight trimmer for weekly lawn maintenance. It’s not the right pick if you routinely tackle overgrown lots or want commercial-level runtime; in those cases, a higher-voltage or larger-deck model is the better buy. For typical suburban trimming, though—and especially with a QuickLoad head—this is a practical, satisfying choice.