EGO ST1623T Review: Line IQ Auto Feed, POWERLOAD and the 4.0Ah Kit

My EGO ST1623T review starts with a clear verdict: buy this 16-inch Line IQ trimmer if tapping a bump head on the ground wears you out, and skip it if you want the lightest tool or one that takes attachments. I used it along the fence lines, the tree-row strips and the gravel edge of our orchard yard. It feeds its own line, winds its own spool and ships with a 56V 4.0Ah battery and charger. Below I cover how the head works, run time, weight, safety and who should look elsewhere.

EGO ST1623T Review: My Verdict in Short

The EGO Power+ ST1623T 16-Inch Cordless String Trimmer is a brushless 56V trimmer with a 16 in. (40 cm) swath, and it suits anyone who trims a lot of fence, bed and tree-row borders and never wants to stop and tap. The head senses a short line and releases more, and a button winds a fresh spool. The price is premium for an EGO trimmer, the line is 0.095 in. only, and 7.67 lb is not light. For more options, I compare nine models for different yards and budgets in my roundup of top string trimmers.

• Who it is for: owners of medium to large yards who trim long runs along fences and beds and want the head to manage the line.
• What it does best: Line IQ feeds line with no bump, so the 16 in. swath stays steady through a long job.
• Main trade-off: it weighs 7.67 lb, takes no attachments and needs an impact wrench for a head swap.

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What Is in the Box and What the Specs Say

The listing sells the kit: the ST1620T trimmer, one 56V 4.0Ah battery and a 320W charger. EGO’s manual covers the ST1620T, the same trimmer without the battery and charger, so the kit adds the pack and the charger and nothing else. The 16 in. swath sets how fast a border goes, and the 4.0Ah pack sets how long you cut before a charge. For long borders, I compare nine picks in my roundup of string trimmers for large yards.

EGO Line IQ vs POWERLOAD: How the Head Works

Line IQ is the feeding head. According to EGO, when either end of the line wears shorter than 7 in. (18 cm), the head releases more line by itself, and the blade on the guard cuts off any excess. There is no tapping and no stopping. A slight tremor in the head is the line being released, which the manual describes as normal.

POWERLOAD is the loading side. A button winds new line onto the spool with the motor, and EGO says a full spool usually takes about 12 seconds. The manual warns against repeating it in rapid succession, because that can damage the motor.

Too much line sticking out overheats the motor, and line length also changes how a trimmer shakes your hands: in a bench test on one petrol trimmer, thread length, engine speed and handle material all shifted hand-arm vibration (1). It was one petrol machine, so I read it as a reason to let the blade hold the length.

Performance on Fence Lines, Tree Rows and Edges

The job decides how much a feeding head is worth. I took the ST1623T through the three places where a trimmer earns its keep on our land, and the head behaved differently in each.

The Fence Line and the Gravel Edge

Along the fence I noticed the head more than the motor. When the line wore short the head gave a small shudder and the swath came back to full width, so I kept walking. I did not stop once to tap the head on the ground, which is the habit I expected to miss. At the gravel yard the guard did its job of turning debris away from my legs, and I still wore eye protection, because stones leave the head fast.

Tree-Row Strips

The 16 in. swath is a wide cut for the grass along the tilled strips under our plum and apricot trees, and I work it along the row. The trees were planted in 2016 and the bark at the base is still thin. EGO’s manual warns that the line damages bark, siding and fence posts, so I kept the whole cutting circle, line tips included, well clear of the trunks and worked along the row, never toward a trunk.

Long Borders on the House Lawn

On the quarter-acre house lawn I used the 2-speed switch the way the manual describes it: low speed, one light on the indicator, for the grass along the beds and the work pad, with the cutting line parallel to the ground as the manual says, and high speed, two lights, for the taller growth in the corners. The manual says low gives better control and longer run time per charge, and that matched how the borders went. For grass over 8 in., EGO says to cut from the top down in small steps, so I did that at the corners instead of forcing the head through. My roundup of string trimmers for tall grass compares nine picks tested on overgrown ground.

Run Time, Speed Modes and Charging

According to EGO, the 4.0Ah battery gives up to 60 minutes of continuous cutting. EGO states no conditions for it, so I treat it as a ceiling, plan my trimming in shorter blocks and keep low speed for the borders.

Heavy growth on high speed will shorten that, as it does on any battery tool. The trigger is variable speed, so more pressure gives more speed, and I ease off between passes. The manual rates the trimmer for 32 to 104 F (0 to 40 C) in use, and it stops cutting when the tool or battery gets too hot, which is a protection and not a fault.

EGO String Trimmer Line Replacement and Reloading

The ST1623T takes 0.095 in. nylon twist line, and EGO names its own line for it. Heavier line overheats the motor, and the manual says never to use metal-reinforced line, wire or rope, because pieces can break off and fly at you or at anyone nearby.

For an EGO Line IQ reload, POWERLOAD does the winding, and the manual gives the order. Release the trigger, let the head stop, then take the battery out first, because the line goes in with the pack off.

1. Release the trigger and wait for the head to stop, then remove the battery pack from the trimmer.
2. Cut one piece of line 14 ft (4 m) long.
3. Push the line into one eyelet until it comes out of the opposite eyelet.
4. Pull the line through until equal lengths show on both sides of the head.
5. Install the battery pack.
6. Press and hold the POWERLOAD button, and release it when about 8.5 in. (22 cm) of line is left on each side.
7. Tap the button briefly to set 7 in. (18 cm) of line on each side.

If the line will not go into the eyelet, EGO says to mount the battery and press POWERLOAD briefly to reset the winding mechanism, then release the trigger, wait for the head to stop and take the battery off again before you thread. If a line is pulled into the head, press the release tabs, take off the lower cover, remove the old line, snap the cover back and load the line again. Before I open the head, I release the trigger, wait for the head to stop and take out the battery.

Replacing the head itself is the one job that is not quick: with the trigger released, the head stopped and the battery out, the manual calls for an impact wrench and gloves. A cracked head is not a field repair, so I plan that one for the bench.

Weight, Balance and Setup

The manual lists 7.67 lb (3.48 kg) for the trimmer, and it does not say whether that counts the battery. I plan for more with the 4.0Ah pack clipped on. At the end of a long border it was the weight I felt first, more than the noise, and the balance of the carbon fiber shaft did not hide it. Stated weights for other cordless models are in my list of lightweight string trimmers.

The shaft is two foldable sections joined by a hinge, with a height-locking clamp that sets the length; I release the trigger, wait for the head to stop and take out the battery before I change it. I set it so the head sat flat with my hands at hip height, which kept my back straighter along the beds. The front handle may need moving after a length change. Never hold the shaft at the hinge, because it pinches fingers, and do not start the tool until the shaft is locked.

In a small lab test, a grass trimmer shook gloved hands more than a backpack blower did (2). That test used a petrol trimmer and EGO publishes no vibration figure for this tool, so I wear gloves as protective gear and take breaks on long jobs.

Care, Safety and Storage

Eye protection comes first. In US emergency room data on lawn trimmer injuries over a decade, the eye accounted for 42.5 percent of the injuries, and foreign objects caused most of them (3). Case reports also show line trimmers injuring bystanders as well as operators (4). EGO’s manual asks for eye protection marked ANSI Z87.1 and hearing protection, so I wear both, with long pants, sturdy boots and gloves. I keep people and pets well clear and stop when someone walks up.

Noise is lower on a battery trimmer, and that is the point for homeowners. In sampling of 80 landscaping workers, those using fuel-powered leaf blowers, string trimmers and chainsaws had significantly more noise and carbon monoxide exposure than with battery versions (5). EGO still warns that noise may contribute to hearing loss, so ear protection stays on. The cordless models I rate are in my roundup of battery string trimmers.

For storage I follow the manual: battery out, tool cleaned with a dry cloth and no hose, kept in a dry ventilated place away from fertilizer, fuel, garden chemicals and deicing salts. Trim only when the grass and weeds are dry, as the manual says. Charge only with the charger EGO lists, never a damaged pack, and not in rain. Any time I clear a jam or change line, the order is the same: release the trigger, wait for the head to stop, remove the battery, then touch the head.

Who Should Buy It and Who Should Skip It

The ST1623T suits a person who trims borders more than they mow.

• Buy it if you trim long borders and dislike tapping or hand-winding line.
• Buy it if you are starting an EGO 56V kit and want a 4.0Ah battery and charger in the box.
• Buy it if you want a variable-speed trigger plus a 2-speed switch for borders and thick growth.

• Skip it if you want the lightest trimmer, because 7.67 lb is not the lightest.
• Skip it if you need attachments or a blade: the manual lists none.
• Skip it if you are on a tight budget, since the tool-only ST1620T costs less.

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Drawbacks and Common Problems

The Line IQ head has more moving parts than a plain bump head, and the motor-driven winding has a rule to respect: repeated winding in quick succession can damage the motor. Beyond that, the real limits are the 0.095 in. line, which keeps thick weeds along the fence out of its range, and a 60 minute claim with no stated conditions. My roundup of string trimmers for thick weeds covers the tougher battery and gas models for heavy growth.

If the trimmer stops mid-cut, the manual’s troubleshooting table points to heavy line, a hot battery or tool, or a missing guard. I check those three in that order, with the head stopped and the battery out before I touch anything. After a shaft length change I also recheck the front handle position before I pull the trigger.

How It Compares With Alternatives

Three trimmers cover the nearest decisions. The table sets the feed type, swath and attachments side by side, with the EGO first.

Makita XRU15PT1

Pick the Makita if you already own Makita 18V batteries and a bump head does not bother you. It has no attachments either, and its 15 in. swath is a little narrower. My comparison of the ST1623T against the Makita XRU15PT1 covers the differences in detail.

Greenworks ST60L413 and Milwaukee 2825-21ST

Pick the Greenworks if you want a 60V battery and a power head that takes compatible Greenworks attachments. Choose the Milwaukee if you already run M18 batteries and want the QUIK-LOK attachment system. Both feed line by bumping the head on the ground, which is the habit the EGO removes. My comparison of the ST1623T against Greenworks ST60L413 covers the attachment question in detail.

My Final Recommendation

The ST1623T is the trimmer I recommend for trimming the borders of a medium to large yard, because the head manages the line and the 4.0Ah kit arrives ready to cut. Read the manual’s order for clearing and loading and follow it every time. That is where my EGO ST1623T review lands: buy it for long borders and auto-fed line, and skip it if weight or attachments matter more to you. If you run M18 packs, my EGO ST1623T vs Milwaukee 2825-21ST comparison is the one to read.

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Frequently Asked Questions

Is Ego LINE IQ worth it?

Ego LINE IQ is worth it if you trim long borders and hate stopping to tap a bump head, because the head releases line by itself whenever an end wears shorter than 7 in. The head is more complex than a bump head, so skip it if you want the simplest machine.

Which Ego string trimmer has LINE IQ?

The EGO ST1623T has LINE IQ, and so does the same trimmer sold without the battery and charger as the ST1620T. EGO also lists other trimmers with LINE IQ on its site, so check the model page for the head type, the shaft and the battery that comes in the box before you buy.

How to load LINE IQ Ego trimmer?

Release the trigger, wait for the head to stop, take out the battery, push one 14 ft piece of 0.095 in. line through the head and pull equal lengths. Then refit the battery, hold POWERLOAD until about 8.5 in. is left each side and tap until 7 in. shows, without repeating the winding quickly.

What are the differences between the EGO bump feed and LINE IQ string trims?

A bump feed head stores line and releases more when you tap it lightly on firm ground, while LINE IQ releases line by itself when an end wears shorter than 7 in. That means no tapping and a steadier swath on LINE IQ, at the cost of a more complex head.

Are Ego tools any good?

EGO tools are a good base for a battery yard kit, and this trimmer shows why, with a brushless motor and a 5-year tool warranty and 3-year battery warranty for personal use, according to the manual. Judge each model on its own weight and run time, because the 60 minute figure here is a maker claim.

References

1. Mallick Z. Optimization of the operating parameters of a grass trimming machine. Appl Ergon. 2010;41(2):260-265. doi:10.1016/j.apergo.2009.07.010
2. Oh J, Chen N, Boyd C. Laboratory evaluation of occupational exposure to hand-arm vibration (HAV) during grounds maintenance equipment operations. Ann Agric Environ Med. 2023;30(2):384-389.
3. Leinert J, Griffin R, Blackburn J, McGwin G. The epidemiology of lawn trimmer injuries in the United States: 2000-2009. J Safety Res. 2012;43(2):137-139. doi:10.1016/j.jsr.2012.03.001
4. Lubniewski AJ, Olk RJ, Grand MG. Ocular dangers in the garden. A new menace: nylon line lawn trimmers. Ophthalmology. 1988;95(7):906-910. doi:10.1016/s0161-6420(88)33076-9
5. Alexander BM, Graydon PS, Pena M, Feng HA, Beamer BR. Hazardous exposures and engineering controls in the landscaping services industry. Journal of Occupational and Environmental Hygiene. 2025;22(3):189-202.

Safety Note: Read your manual first. A string trimmer or brush cutter throws debris with force, so clear stones, glass and wire from the area before you cut. Wear impact-rated eye protection with side coverage that meets ANSI Z87.1, hearing protection, gloves, heavy long pants, long sleeves and sturdy slip-resistant boots (steel-toe where your manual says so). Keep people and pets at least as far away as your manual says (50 feet in some manuals, 100 feet in others), and stop if anyone comes closer. Keep the correct guard fitted, use only the cutting attachments, handles and harness the maker approves for your exact tool, and never replace trimmer line with wire. A blade can kick sideways when it hits a stump or a thick stem, so fit the handlebar and harness your manual requires for blade work, hold both handles firmly and keep secure footing. Before you clear a jam, clean the tool or change line, a blade or an attachment, switch it off, wait for all movement to stop, then remove the battery, unplug the cord or disconnect the spark plug wire. Refuel a gas model outdoors with the engine off and cool, away from flames or sparks, and move away from the fueling spot before starting, as far as your manual says (often 10 to 30 feet); never run it in a garage, shed or other closed space. For a battery model, use only the maker’s battery and charger, charge it within the temperature range in your manual and never use a damaged or swollen pack. For a corded model, use a GFCI outlet, keep the cord clear of the cutting line and avoid wet conditions.