EGO Power+ ST1623T 16-Inch Cordless String Trimmer

Overview

The EGO Power+ ST1623T is a 56V cordless string trimmer with two features that no competitor matches: POWERLOAD automatic line winding and Line IQ auto-feed. POWERLOAD lets you thread a pre-cut length of line through the head, press a button, and the motor winds it for you in about 15 seconds. Line IQ monitors the line length while you trim and feeds out more when it gets short. You never bump the head. You never stop trimming.

Pro Tool Reviews gave it a 9.7 out of 10, calling it "the top rated string trimmer that we've used for homeowners." TechGearLab named it their Editors' Choice, saying it "impressed at every stage of testing." In Project Farm's shootout of nine battery string trimmers, the EGO had the longest runtime by a wide margin and the fastest line reload time.

The kit includes a 4.0Ah 56V battery and a 320W charger. If you already own EGO outdoor power tools, you can buy the bare tool and use the batteries you have.

Key Features

The brushless motor spins between 3,500 and 5,500 RPM through a two-speed digital selector. Low speed runs 3,500 to 4,800 RPM for edging and light work. High speed tops out at 5,500 RPM for thick weeds and overgrown areas. A variable-speed trigger gives you fine control within each range.

The carbon fiber shaft is telescoping, so you can adjust the length for your height. EGO puts a lifetime warranty on the shaft when registered within 90 days of purchase. The whole trimmer weighs 7.4 lbs bare. With the 4.0Ah battery, it comes to about 12.5 lbs.

The cutting swath is 16 inches using dual 0.095-inch lines. Line IQ keeps both lines at that full 16-inch width automatically. When either line drops below about 7 inches, the head feeds out more. The system is IPX4 rated, so rain won't kill it.

EGO's 56V battery platform covers mowers, leaf blowers, chainsaws, hedge trimmers, and more. One battery system for the whole yard.

Performance

In Project Farm's head-to-head test of nine trimmers (EGO, DeWalt, Milwaukee, Makita, Greenworks, Ryobi, Echo, Kobalt, and Atlas), the EGO ran for 40.5 minutes at wide-open throttle. That's more than double the DeWalt 60V's 17 minutes and the Milwaukee M18 FUEL's 16 minutes. EGO does this by automatically dialing back RPM when the motor doesn't sense resistance, saving battery for when you actually need it.

Cutting speed is a different story. Project Farm's tall-grass test had the EGO at 89 seconds to clear an 8x24-foot patch, while the DeWalt finished in 68 seconds. The EGO's startup torque measured 26 in-lbs versus DeWalt's 73 in-lbs. So the DeWalt hits harder, but the EGO lasts two and a half times longer.

Pro Tool Reviews ran the ST1623T for over an hour on high speed. On low speed, runtime stretches even further. One owner on the Garage Journal forum reported 1.5+ hours on low with the 4.0Ah battery.

The Line IQ system works as advertised but has a trade-off: it feeds line aggressively, which means you go through string faster than a bump-feed trimmer. One YouTube reviewer noted he'd burned through nearly all of a 14-foot length after just three mowing sessions. Line is cheap, but it's worth knowing. Several owners on the EGO Community Forum also recommend swapping the stock EGO orange line for Oregon Gator or Greenworks 0.095-inch line, which they say is less brittle and breaks less often.

Noise is 81.1 dB at 20 inches in Project Farm's test. That's the quietest among premium competitors (DeWalt hit 89.5 dB, Milwaukee 89.4 dB). You don't need hearing protection, and your neighbors won't hate you on Sunday mornings.

Build Quality & Design

The carbon fiber shaft is light and stiff. It won't flex or rattle under load. The single-trigger mechanism is an improvement over EGO's older two-trigger design, and the digital speed selector is simple. The trimmer head is well-sealed at IPX4.

The main design drawback is weight distribution. Project Farm measured 4.5 lbs at the trimmer head alone, the heaviest of all nine tested. That front-heavy balance gets tiring on long sessions. EGO includes an attachment point for a shoulder strap, but the strap itself isn't in the box. You'll want to buy one separately if you have a big yard.

Height is also a factor. One YouTube reviewer who is 5'3" found the guard catching the ground constantly because the Line IQ head is taller than older EGO models. If you're 5'6" or under, try holding one in a store before buying.

Amazon reviewers (4.4 stars, 2,000+ ratings) report years of reliable use. One 87-year-old volunteer uses his for extensive trimming at a nature education center, tackling thistles, briars, and high grass on terrain the riding mower can't reach. He wrote that it "just keeps going." The 5-year tool warranty is the longest in the category (DeWalt and Milwaukee both offer 3 years). Multiple owners report EGO honoring the warranty quickly, including battery replacements shipped before the old one was returned.

Value for Money

The kit sits at the top of the price range for cordless string trimmers. The bare tool (model ST1620T) costs roughly 40% less if you already have EGO batteries. For comparison, Milwaukee's M18 FUEL kit costs less, and DeWalt's 60V FLEXVOLT kit is in the same ballpark. The Greenworks 80V kit costs significantly less.

What you're paying for is the POWERLOAD and Line IQ combination. No other trimmer loads and feeds line automatically. If you trim a few times a week or manage a large property, the time saved on line changes adds up. If you trim twice a month on a small lot, the premium is harder to justify.

The EGO 56V ecosystem is outdoor-only (mowers, blowers, chainsaws, snow blowers). DeWalt's 20V/60V system has 100+ tools spanning power tools and outdoor equipment. Milwaukee's M18 has 200+. If you already own DeWalt or Milwaukee batteries for workshop tools, buying into a separate EGO battery platform just for a trimmer is a tougher sell.

Who Should Buy This

Homeowners with medium to large yards who trim weekly. The long runtime and auto-feed mean you can work through the whole property without stopping to charge or bump the head.

Anyone switching from gas. The EGO is quieter, lighter, and starts every time. No mixing fuel, cleaning carburetors, or pulling a cord. Owners on r/lawncare and the Garage Journal consistently say their gas trimmers have been collecting dust since they switched.

People already in the EGO 56V ecosystem. If you have an EGO mower or blower, the ST1623T is the obvious trimmer choice. Buy the bare tool and save.

Who Should Skip This

If you need attachment versatility, look at the DeWalt DCST972 or Milwaukee 2825-21ST. Both accept edger blades, pole saws, and hedge trimmers. The EGO is a trimmer and nothing else.

If raw cutting power matters more than runtime, the DeWalt 60V is the stronger machine. Project Farm measured nearly triple the startup torque, and it cleared tall grass 24% faster. Landscapers and pros doing heavy clearing should lean toward DeWalt.

If you're on a budget, Ryobi's 40V trimmer or the Greenworks 80V kit cost significantly less and still earned solid marks in testing. You give up auto-feed and auto-load, but you keep more money in your pocket.