Troy-Bilt Cordless String Trimmer TB4200 Featured String Trimmers

Troy-Bilt Cordless String Trimmer (TB4200): Product Review

GPR Recommendation

Ease of Use
Final Thoughts

A powerful, well-designed trimmer that can handle the tough stuff with ease.

Overall Score 4.8

Available on Amazon

Buy It

If you’ve decided that it’s time to move from a gasoline-powered string trimmer to one of the new cordless, Lithium Ion (Li-ion) battery powered units, you’ll want to consider Troy-Bilt’s new TB4200 string trimmer. This 40V 4.0Ah (Amp hour) trimmer incorporates their new CORE technology that promises to match the power of a gasoline trimmer.

I recently tried one at our ¾ acre testing ground where I put it through its paces on a wide range of plant material and trimming/edging situations. Here’s what I found.

Troy-Bilt Cordless String Trimmer TB4200

It’s time to move from a gasoline powered string trimmer to one of the new cordless, Lithium Ion (Li-ion) battery powered unit

Related Article: Best Cordless, Battery-Powered String Trimmers


  • Engine/Motor: 40V Max, 4.0Ah Li-ion (144 watt hours)
  • Speed Settings: Variable
  • Attachment Capable: No
  • Line Release: Dual line bump head
  • Cutting Swath: 16″
  • Line Diameter: .090″
  • Charger Included: Yes – with String Trimmer Kit
  • Battery Included: Yes – with String Trimmer Kit
  • Weight with Battery: 12 lbs.
  • Weight without Battery: 8.6 lbs.
  • Warranty: 5 years on string trimmer / 3 years on battery

Troy-Bilt Cordless String Trimmer TB4200 in Use

When the unit arrived, it was packed in a long box with colorful advertising all over the exterior.  The trimmer arrived unscathed.  The internal packaging was great.  Even the included charger and battery came through without a hitch.

Troy-Bilt Cordless String Trimmer TB4200 Packing-Box

The trimmer arrived packed in a long box with colorful advertising all over the exterior.

The handle came through as a separate piece that had to be installed.  It was a simple procedure that only required tightening a bolt with a flat-head screwdriver (supplied by you).

When I finally got it unpacked, I could see right away that I was dealing with a new technology.  The cutting head of the TB4200 was robust, as was the battery.  My first impression was that this trimmer is a serious homeowner unit that borders on commercial grade.

About the CORE Technology

So what makes this “CORE” technology so different from other string trimmer technologies on the marketplace today?  According to Troy-Bilt’s marketing materials, power comes from the motor, not the battery. Instead of a typical brushless motor design, the CORE technology uses a state-of-the-art, printed circuit board in the motor that allows it to deliver concentrated, efficient power when and where it’s needed. This generates a high degree of torque, which is the primary force that lets you cut through even the toughest plants.

Troy-Bilt Cordless String Trimmer TB4200 Trimmer Head

A powerful motor in the cutting head gives this Troy-Bilt trimmer a lot of “oomph”

Troy-Bilt is following a growing industry trend by using brushless motors in power tools. Some have used the phrase “smart tool” to describe tools with these motors.  In layman’s terms, a brushless motor senses when more power is required.  For example, when the TB4200 trimmer encounters tall, thick, wet grass, its sophisticated electronics sense that it needs more power to cut through this stuff.  Conversely, when edging around beds, shrubs, etc., or in shorter dry grass, the microcircuits sense that less power is needed and the motor’s energy is reduced.

Basically, “smart tools” regulate the amount of power to the motor based on the task at hand, thereby increasing the battery life available to the tool.


The trimmer comes packaged with a 6 Amp charger (that fits a 120V outlet) and a 40V, 4.0Ah Li-Ion battery.

The first thing you’ll notice about the battery is that it’s cylindrical, rather than the typical brick shape found on other brands.

As with all battery-powered tools, the TB4200 battery has to be fully charged before use.

The battery takes approximately 50 minutes to reach a full charge.

>> See our FAQs About Li-Ion Batteries

Troy-Bilt Cordless String Trimmer TB4200 Core Battery

The battery takes approximately 50 minutes to reach a full charge


When inserting the battery into the battery compartment, located at the back of the unit, I was a little surprised at the weight.  The trimmer weighs 12 lbs. with the battery installed and about 8.6 lbs. without the battery.  It was heavier than I expected, but not so heavy that I couldn’t get the job done without resting.

The TB4200 comes with a strap clip that is integrated into the shaft of the unit but the boxed unit didn’t come with a shoulder strap.  I would have liked to have seen a strap as part of the purchase as it would have taken some of the load of carrying 12 lbs. of string trimmer.

Using the String Trimmer

The unit was well balanced.  The 3.4 lb. battery offset the weight of the shaft and motor head nicely.  This combined with the moveable handle made for excellent balance.  I could move the front handle back and forth to achieve that sweet spot of perfect equal tipping points.

The throttle of the Troy-Bilt Cordless String Trimmer Model TB4200 has both a throttle lockout switch (located on top) and a variable speed throttle control lever (located on the underside of the handle grip area).

The handle was comfortable and I was glad to see the safety switch feature.  I believe you can’t have enough safety features on power equipment these days.

The power meter display is located just ahead of where you grip the throttle handle area.  It’s a well laid out screen that shows various power output levels.

The trimmer normally operates in what Troy-Bilt calls “ECO mode” to conserve energy for maximum run time.  I found that ECO mode was fine for most jobs.

There’s also a “boost” button; just push it to give the unit maximum power output when tackling tougher plant material.

The trimmer will reset to ECO mode a few seconds after the motor is turned off.

Another nice feature is the variable speed throttle.  This helped most with managing battery life, but it also made for that “just right” speed to do both delicate and full-on, bull-your-way-through work.

Troy-Bilt Cordless String Trimmer TB4200 Controls

It has a variable speed throttle which enhances battery life.

Battery Life

The battery life was decent.  In a 40 minute period of time, I was able to trim the perimeter of a ¾ acre property and had plenty of power left to take on some of the heavier jobs.

With the brushless motor and the handle-mounted power indicator, I could manage my battery life based on the amount of grass I needed to trim. The power management system is one of the really nice features of this unit – this “smart tool” technology really works.

Troy-Bilt TB4200 String Trimmer Battery Indicator

The brushless motor and the handle-mounted power indicator manages the power system well.

Cutting Power

I found the Troy-Bilt trimmer almost ridiculously powerful, particularly in the boost mode.  I even cut my way through some nasty desert native grasses (this stuff is shrub-like) that I’d originally thought would require me to get out the field mower.  And there were times when just a light touch of the variable speed throttle gave me enough power to trim around sensitive plants without cutting them off at the stalk.


The dexterity of the unit was also good.  The ambidextrous handle made it easy to turn the trimmer on its side for edging or use in those areas that needed an angled cut.  And even though the unit was a little heavy, it maneuvered nicely in hard to reach places and tight spaces. If I needed to adjust the handle either forward or backward for better balance, all I had to do was loosen the bolt that went through the handle, slide the handle on the TB4200 shaft to the ideal position and tighten the bolt with a standard flat-head screwdriver.

Troy-Bilt TB4200 String Trimmer Handle

The ambidextrous handle makes it easy to turn the trimmer.

Dual Line Bump Head

And when I needed more trimming line, the dual line bump head delivered.  The string that came with the unit had a unique axial twist line to it.  It looked like a reinforced line.  All I can tell you is I whacked the heck out of this line on rocks, and wooden and steel posts and the line took the abuse.  Rarely did I have to advance the line.

The 16” cutting radius gives plenty of room for virtually any trimming operation.

Troy-Bilt TB4200 String Trimmer Head

The 16” cutting radius gives plenty of room for virtually any trimming operation.

Easy Trimmer Line Reloading

The Troy-Bilt 4200 has designed a unique sting loading system that requires no bump head disassembly to replace the trimmer string.

When you run out of string trimmer line, all you have to do is take a 16′ pre-measured/pre-cut replacement trimmer line (which is available from Troy-Bilt and Lowe’s), thread it through one of the bump head exit holes and insert it into a visible hole in the string spool.  Keep pushing the line directly through the head (at the arrow marked “load”) until it comes out the other side of the bump head string exit hole.  Make sure you have an equal length of string coming out each exit hole.

Next, turn the top cap of the bump head and it will reel in the string.  The cap is clearly marked “wind” and has a counterclockwise arrow showing the correct direction to reel in the new line inside the head.

Keep turning until the trimmer line is the correct length (just inside the guard) and you’re ready to go.

Troy-Bilt TB4200 String Trimmer Head Disassembled

The line can be easily replaced using the quick loading line replacement system.  There is no need to remove the trimmer clip on the head assembly to expose the line trimmer spool.  I just included this picture to show the internal working mechanism.


The small cutting head guard is what I’d expect on a commercial grade unit, but not one that’s marketed to homeowners and the DIY crowd.  Flying debris was problematic from time to time because of the small cutting guard.  But sometimes you have to trade off maneuverability (which requires a smaller guard) with practicality (which requires a larger guard).

In all instances, due to the nature of “weed whacking”, safety glasses are a must (I recommend these glasses from John Deere/Wiley X ). I also recommend wearing long pants and boots to protect yourself from airborne debris.


Troy-Bilt offers a 5-year limited lifetime warranty on the string trimmer and motor, and a 3-year limited warranty on batteries.  As limited warranties go, it covers defects in materials and workmanship.  Pretty much everything else is not covered.


The Troy-Bilt Cordless String Trimmer (Model TB4200) was extremely powerful when I needed the high-end torque to blast through the heavy stuff, yet nimble enough to adjust to a lower power setting when more finesse was required.  The battery life was good to excellent.  I wouldn’t want to mow field grass for long, but for the average homeowner’s lawn, the TB4200 is a great tool.  It was well-balanced but a little heavy and I would like to have seen a shoulder strap.  All in all, you can’t go wrong with this string trimmer.  It is well designed and functioned exceedingly well in my tests.

Where to Buy

Your best option to buy the Troy-Bilt Cordless String Trimmer (Model TB4200) is on Amazon as either a kit or bare tool (this is a good option if you already own a Troy-Bilt charger and the right batteries). It’s also available from the Troy-Bilt website and at Lowes.  Both outlets offer the packaged unit for $279.00.  The package includes the charger and a 40V 4.0Ah battery.

Troy-Bilt CORE TB4200 40V 16-Inch Straight Shaft Cordless String Trimmer Kit
The complete kit is your best buy (unless you already own a Troy-Bilt battery and charger)

It is also available as a stand-alone unit from Troy-Bilt (without the battery or charger) for $179.00.

A spare battery from Troy-Bilt costs $149.00.

If I had to buy all three as separate components I would be spending $417.00 ($179.00 trimmer + $89.00 charger + $149.00 battery) vs. $279.00 for the kit. Looking at the Lowes website, there is no indication that they offer spare batteries, so I guess you’ll have to order those directly from Troy-Bilt at $149.00 each.

Last update on 2023-03-31 / Affiliate links / Images from Amazon Product Advertising API

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