● String Trimmers · Review

EGO Power+ ST1521S 15-Inch String Trimmer

Sponsored link · confirm price and availability on Amazon · updated October 16, 2026

✎ PickHonest Research Desk▦ Updated October 15, 2026◷ 4 min read

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EGO Power+ ST1521S 15-Inch String Trimmer

EGO Power+ ST1521S 15-Inch String Trimmer

Carbon fiber shaft keeps weight low without sacrificing reach on an incline

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Pros

  • Pivoting head locks cleanly into edging position without extra tools
  • POWERLOAD auto-feed threads new line in seconds, useful after a long edging session wears the line down
  • 56V battery has enough torque to run the line against curb edges without bogging
  • Carbon fiber shaft keeps the tool light for one-handed edging control

Cons

  • 56V battery and charger add cost versus 40V competitors
  • Proprietary EGO battery doesn't cross over to other brands
  • No built-in guide wheel, so depth control is by feel

Is the EGO Power+ ST1521S 15-Inch String Trimmer worth it?

Yes, for the right buyer. The EGO Power+ ST1521S 15-Inch String Trimmer ranks #1 in our Best String Trimmers for Edging list. Its biggest strength: pivoting head locks cleanly into edging position without extra tools. The ma in caveat: 56V battery and charger add cost versus 40V competitors.

Alternatives to the EGO Power+ ST1521S 15-Inch String Trimmer

Products ranked near it in our research, each better for a slightly different buyer.

Buying advice: string trimmers

  • 1Cordless suits most homes. Gas suits large or overgrown lots. Corded suits small yards.
  • 2Bump feed releases line when you tap the head. Automatic feed is convenient but can waste line.
  • 3Wider swaths cover more ground per pass. 13 to 16 inches suits most yards.
  • 4Straight shafts reach under bushes and suit taller users. Curved shafts are lighter and easier to handle.
  • 5Attachment-capable trimmers can take edgers, pole saws and cultivators.

Read the full guides

  • How to Choose a String Trimmer
  • String Trimmers Buying Guide
  • String Trimmer Line Not Feeding
  • String Trimmer Not Starting

More string trimmers shortlists

  • Best String Trimmers for Edging
  • Best String Trimmers for Small Yards
  • Best String Trimmers for Steep Hills and Slopes
  • Best String Trimmers for Thick Weeds and Overgrown Lots
  • Best String Trimmers Under $100
  • Best String Trimmers Under $200

FAQ

Common questions

Is the EGO Power+ ST1521S 15-Inch String Trimmer worth buying?

Yes, for the right buyer. The EGO Power+ ST1521S 15-Inch String Trimmer ranks #1 in our Best String Trimmers for Edging list. Its biggest strength: pivoting head locks cleanly into edging position without extra tools. The ma in caveat: 56V battery and charger add cost versus 40V competitors.

Who is the EGO Power+ ST1521S 15-Inch String Trimmer best for?

Based on our research it suits edging, steep hills and slopes, budgets under $200 and thick weeds and overgrown lots. It's ranked #1 of 5 in our Best String Trimmers for Edging list.

What are the downsides of the EGO Power+ ST1521S 15-Inch String Trimmer?

The ma in trade-offs owners and reviewers point to: 56V battery and charger add cost versus 40V competitors; proprietary EGO battery doesn't cross over to other brands; no built-in guide wheel, so depth control is by feel.

What are the key features of the EGO Power+ ST1521S 15-Inch String Trimmer?

15-inch cutting swath with POWERLOAD auto-feed line, 56V ARC Lithium battery, 2.5Ah included, Carbon fiber split shaft, Pivoting head for vertical edging and Brushless motor.

What are the best alternatives to the EGO Power+ ST1521S 15-Inch String Trimmer?

Worth comparing: Worx WG183 40V String Trimmer, Greenworks 40V 12-Inch Cordless String Trimmer and Husqvarna 128LD Gas String Trimmer. Each ranks near it in our research for a slightly different buyer.

Where can I buy the EGO Power+ ST1521S 15-Inch String Trimmer?

It's sold on Amazon. Prices and stock change often, so check the current listing before you buy, our link takes you straight to it.

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