EGO Power+ ST1521S Review
An honest, research-based look at the EGO Power+ ST1521S: what it does well, where it falls short, and who should actually buy it.
- BuyOnceRight Research Desk
- Updated
- 3 min read
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Our verdict
The EGO Power+ ST1521S is a solid option in its class with clear strengths and a few honest tradeoffs. It suits buyers whose priorities match its strengths above; if your needs differ, the alternatives below are worth a look.
An honest, research-based look at the EGO Power+ ST1521S: what it does well, where it falls short, and who should actually buy it.
Who should buy it?
A good fit if you…
- The EGO ST1521S is right if: you want the strongest cutting performance available in a cordless trimmer, value the POWERLOAD auto-feed convenience, and are open
- Consider alternatives if: you already own 40V tools from another brand, need brush-cutter blade compatibility for heavy brush, or are working with a tighter bud
Look elsewhere if you…
- Buyers who need a different feature set, check the alternatives below.
What You Are Buying
The ST1521S is a 15-inch cordless string trimmer built around EGO's 56V ARC Lithium battery system.
The shaft is carbon fiber, which is both lighter and stiffer than the plastic or aluminum shafts common on cheaper trimmers, and it telescopes for height adjustment.
The head pivots for edging, a feature not universal even at this price tier.
Performance
Everyday lawn trimming: at moderate speed, the 56V brushless motor holds line speed consistently through typical residential grass without bogging.
The 15-inch swath covers ground efficiently compared with the 12 to 13-inch swaths common on budget trimmers.
Dense or overgrown patches: with 0.095-inch line installed, the motor keeps pushing through thicker growth that stalls lighter 40V trimmers.
It's not a substitute for a gas trimmer or brush cutter on genuinely woody brush, but it handles overgrown lawn grass and moderate weeds well.
What It Does Well
POWERLOAD is the standout convenience feature.
Line feeding on most trimmers means stopping, removing the spool, unwinding tangled line, and rewinding it correctly.
POWERLOAD replaces that with feeding new line into a port and pressing a button.
The carbon fiber shaft is a genuine build quality upgrade.
What Falls Short
Proprietary battery platform.
The 56V ARC Lithium system doesn't interchange with more common 40V tool lines from other brands.
If you already own 40V tools from a different manufacturer, the ST1521S doesn't share batteries with them.
Cost for extended runtime.
Who Should Buy It
The EGO ST1521S is right if: you want the strongest cutting performance available in a cordless trimmer, value the POWERLOAD auto-feed convenience, and are open to building an EGO 56V tool ecosystem over time.
Consider alternatives if: you already own 40V tools from another brand, need brush-cutter blade compatibility for heavy brush, or are working with a tighter budget where the Greenworks 40V or Worx WG183 cover your yard's actual needs.
See Also
Best String Trimmers for Edging EGO Power+ ST1521S vs Ryobi 40V String Trimmer
EGO Power+ ST1521S
Check current price, availability and owner reviews.
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Frequently asked questions
Does the EGO ST1521S come with a battery and charger?
Yes, the standard kit includes a 56V 2.5Ah ARC Lithium battery and a standard charger. Larger battery options, 4.0Ah, 5.0Ah, and up, are sold separately and increase both runtime and total cost.
How long does the included battery run on a full charge?
Typical light to moderate trimming runs 30 to 45 minutes on the included 2.5Ah battery, depending on grass density and how much time is spent at full trigger. Heavy, dense growth reduces that runtime noticeably. For larger properties, a 4.0Ah or 5.0Ah battery extends runtime meaningfully.
What is POWERLOAD and is it worth having?
POWERLOAD is EGO's auto-feed line system that lets you feed new trimmer line into the head by pressing a button and pulling, rather than disassembling the spool. For anyone who trims regularly enough to run through line, it removes what is otherwise the most tedious part of trimmer maintenance.
Is the 56V battery compatible with other EGO tools?
EGO's 56V ARC Lithium batteries are shared across its mower, blower, chainsaw, and other outdoor power tool lines. Buying into the ST1521S makes sense as part of a broader EGO tool ecosystem, since additional tools can reuse the same batteries and charger.
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