Let’s cut through the noise. A cordless string trimmer isn’t hard to choose — unless you’re drowning in marketing fluff. I’ve tested over 60 trimmers in the last five years, and most of them are either overpriced or underbuilt. This guide will tell you what actually matters.
Why Your Choice Matters
A bad trimmer makes yard work miserable. You get tangled line, weak cutting, or a backache after ten minutes. A good one saves time and money. The difference often comes down to three things: voltage, feed system, and ergonomics. Ignore the color of the brand — look at the specs.
If you have a small yard, a 20V trimmer is usually fine. For medium to large properties, you’ll want 40V or higher. And please, do not buy a trimmer with a brushed motor unless you enjoy replacing it every season.
Key Features Explained
Voltage & Power
Voltage determines how hard the motor can push the line. 20V works for light trimming — edging along sidewalks, touching up around flower beds. But for thick grass or overgrown weeds, you need 40V or even 60V. The higher voltage trimmers have more torque and can cut through heavier material without bogging down.
That said, more voltage usually means bigger batteries and more weight. Balance is key. For most homeowners, a 40V system is the sweet spot: enough power for real work, but still manageable for an hour or so.
Cutting Width & Line Feed
Cutting width ranges from 10 to 18 inches. Wider means fewer passes, but also more strain on the motor. I’d recommend 13-15 inches as a good balance. For line feed, you have two options: bump feed and auto feed. Bump feed is more reliable — you tap the head on the ground to advance the line. Auto feed can jam or overfeed in wet grass. Stick with brushless models that use bump feed; you’ll thank me later.
Line diameter matters too. 0.065″ is for light duty. 0.080″ is for general use. 0.095″ or thicker tackles heavy weeds. Make sure the trimmer accepts the size you need.
Weight & Ergonomics
Weight is the number one complaint I hear. A heavy trimmer with a bad handle will make your shoulders scream after 20 minutes. Look for something under 10 pounds with the battery. Curved shafts are lighter and easier to maneuver but less durable. Straight shafts give better reach under shrubs and are usually more robust.
If you’re a beginner or elderly, prioritize weight over power. A 20V trimmer that’s 7 pounds will be much more pleasant than a 10-pound 60V beast. You can always take an extra pass.
Battery System
This is where ecosystem lock-in bites you. Once you buy a trimmer from a brand, you’re likely stuck with their batteries forever. Runtime depends on the amp-hour (Ah) rating. A 4Ah battery on a 40V trimmer gives about 30-40 minutes of continuous trimming. If you have a large yard, buy two batteries or a fast charger.
Also check if the charger supports rapid charging. Some budget trimmers come with a charger that takes 4+ hours. That’s a dealbreaker for me.
Top Brands Compared
Here’s a quick breakdown of the major players I’ve tested:
- Worx: Good value, lightweight, but battery life can be average. Their PowerShare ecosystem is handy if you own other Worx tools.
- Ryobi: Huge lineup and great battery compatibility across tools. The 40V HP brushless trimmer is solid. Under $150 often.
- DEWALT: If you’re already on their 20V or 60V platform, skip the generic adapter trimmers. Their own models are tough but heavy.
- EGO: The gold standard for power and runtime. Pricey, but you get commercial-level performance. Worth it for large properties.
Our Recommendations
Best Budget: Ryobi 18V One+ brushless. Under $100, good for small yards, and the battery works in dozens of other tools.
Best Value: Worx WG163 20V. Light, quick to assemble, and cuts well. Ideal for beginners.
Best Power: EGO Power+ ST1521S. 56V, 15″ cutting width, and the line feed is nearly flawless. Yes, it’s expensive, but it’s the last trimmer you’ll buy for years.
Best Lightweight: Black+Decker LST136 40V. Only 7.3 pounds with battery. Perfect for small to medium lawns.
FAQ
Can I use any battery brand with any trimmer? No. Each brand has proprietary connectors. If you already have a tool ecosystem, buy a trimmer that fits it.
Which is better, curved or straight shaft? Curved for light trimming and comfort. Straight for reach and durability.
How long do batteries last? Typically 2-5 years depending on cycles. Store them indoors and don’t drain them completely.
Do I need brushless? Yes. Brushless motors are more efficient, quieter, and last much longer than brushed ones. Spend the extra $20.
Can I use a trimmer for edging? Many models have a head that rotates 90° for edging. Check before you buy.
What’s the difference between 20V, 40V, and 60V? Higher voltage = more power and faster cutting, but also heavier batteries. Choose based on your yard size and grass thickness.
For more detailed comparisons, check out our best cordless string trimmers guide.
