The Stihl FSA 80 R Battery Trimmer: A Hands-On Review

Midsize and large yards present a diversity of challenges when it comes to landscaping. One homeowner may have a weed-free lawn that simply requires trimming and edging. Another may need to consider natural areas or drainage swale maintenance, or seasonal landscape bed cleanup. When searching for the right tool for the job, some shoppers may prioritize runtime and operating comfort, while others may need aggressive cutting power and versatility. I recently tested the Stihl FSA 80 R Battery Trimmer, and believe it could be a contender for either case.

Stihl has been a leader in the outdoor power equipment industry for nearly a century. Most of those years, it focused on developing and manufacturing durable and dependable professional-grade forestry and property-maintenance equipment. That pro-quality focus has matured well as the brand moved into the residential tool market and later developed its battery-powered products. Its FSA 80 R battery trimmer showcases the brand’s continued commitment to dependable quality and performance.

Having previously tested dozens of battery string trimmers, my favorites have always been the ones that perform like gas-powered equipment. Lightweight trimmers are nice, but it’s frustrating if they don’t cut fast and clean. As for runtime, the industry average seems to lie somewhere between 45 and 60 minutes, which is more than enough time to do all of the routine trimming and edging around my yard. The reason I liked the Stihl FSA 80 R well enough to write this review is because although it had a shorter battery life than many of its peers, it outperformed them when it came to actual cutting ability. It was fast and aggressive, with low vibration and excellent balance. Here, I’ll share my observations from 4 hours of testing to help you decide if it could be the right trimmer for your property.

• Shorter runtime per charge and slower recharge than some other battery trimmers

Get the Stihl FSA 80 R battery trimmer at:

• Northern Tool + Equipment for $399.99
• Stihl for $399.99

What is the Stihl FSA 80 R battery trimmer?

The FSA 80 R is one of the more powerful battery-powered weed trimmers in Stihl’s residential tool lineup. It comes equipped with a bump-advance string trimmer head that works with either 0.095- or 0.105-inch-diameter weed eater string, and a 36V 4 Ah lithium-ion battery. The trimmer features a variable-speed throttle trigger and a loop handle with quick-release for fast tool-free adjustment. In average cutting conditions, the FSA 80 R runs up to 25 minutes per charge. The included charger replenishes the AK 20 battery in 180 minutes.

My test location was a ¾-acre lot with 350 linear feet of curbed driveway, 800 feet of wood privacy fence, and a plethora of landscape bedlines to trim. The vegetation included lawn grass plus a weedy natural area with a mix of coarse green growth and woody vines (think greenbriar, poison ivy, and Virginia creeper). Spooled with 0.095-inch round trimmer line, the FSA 80 R delivered excellent results. It operated smoothly overall and easily handled all of the vegetation in its path.

Power and Performance: 4.5

A battery trimmer with enough torque and head speed to run 0.095- or 0.105-inch trimmer line should easily perform routine trimming and seasonal cleanup work in a suburban yard. In this respect, the Stihl grass trimmer excelled. The cutting force felt similar to that of a 25-cubic-centimeter 2-cycle gas trimmer, which is to say it buzzed through everything up to ¼-inch diameter tree seedlings without hesitation. On a couple of occasions I encountered thicker tree seedlings that only a brush cutter would take down, so I moved on. Not once did I have to slow down along the grassy edges, and I was able to scythe through overgrown weedy spots at a steady clip. 

After trimming through four battery charge cycles, I calculated an average of 31 minutes of runtime per charge. That’s not a long time compared to other popular models, but it’s better than expected. The 3-hour recharge time on the included charger was longer than I liked, so I opted to use the AL 500 lightning charger (sold separately) to do the job in just 45 minutes. For those who need more runtime, I recommend buying a second AK 20.

Ease of Use: 5

Some battery-powered string trimmers come equipped with power switches that are located on other parts of the machine, or have oddly placed eco-mode controllers that can be a bit clunky. The FSA 80 R has none of those issues. With a charged battery installed, simply grip the upper handle naturally, flip the trigger safety interlock with your thumb, and then squeeze the throttle trigger. The trigger is very responsive, increasing trimmer head revolutions per minute steadily from zero to maximum speed through the full range of movement. There is an eco-mode switch that is easily accessible with the thumb on the throttle hand.

Other factors that I considered were the weight, balance, and trimmer head operation. With regard to weight and balance, I was totally satisfied. At a little over 13 pounds, it was comparable to many gas trimmers and lighter than some other battery-powered models. The weight was well balanced between the trimmer head and the motor. The Auto Cut 27-2 trimmer head itself was a simple bump head that spooled out new line when tapped on the ground. After running through a whole spool, I was able to reload the spool within 2 minutes. 

Safety: 5

Battery-powered grass trimmers are generally easier to use than gas. But this can be detrimental when it comes to safety, especially if curious children are part of the equation. For that reason, the FSA 80 R is equipped with a battery-retaining latch that prevents the unit from unintentional starts. When the battery is first inserted, it clicks into place and stays put, but the motor will not start. A second push and click sets the battery into the operating position.

Another feature that helps prevent accidental starting is the trigger interlock. With the battery in the operating position, you’ll want to grip the handle in order to depress both the presence switch and thumb lever on the side of the rear handle before squeezing the trigger. Until the thumb lever is depressed, the trigger remains locked. Also, the motor will not run if the presence switch is not depressed, even with the trigger interlock lever depressed. Three switches on one handle may sound complicated, but it is well designed and not at all cumbersome. The best thing about these safety features is that they functioned as intended, adding a layer of prevention without burdening the operator.

Is the Stihl FSA 80 R battery trimmer worth the money? 

The FSA 80 R has a suggested retail price of about $400, which is fair. Among the larger group of 15-inch battery trimmers that I tested, the Stihl FSA 80 R was slightly more expensive than average. In terms of trimming power and operating comfort, it was my personal favorite. The motor ran smooth and strong with very low vibration. It cut cleanly through grass and had no trouble clearing coarse vegetation in weedy areas. The design was well balanced and included an adjustable front handle with a quick-release attachment to easily custom-fit the machine to different users. 

The weak point was runtime per battery charge. The promoted average runtime of 25 minutes, and average of 31 minutes in my tests, was one of the shortest within the test group. But that was still enough time to do the routine trimming and edging around my yard after mowing. For more intensive work, I would have wanted to buy a second battery and a lightning charger. 

Should you buy the Stihl FSA 80 R battery trimmer? 

As one of the most reliable brands in the outdoor power equipment industry, Stihl often enjoys the benefit of the doubt when its loyal customers need new equipment. But the brand built its reputation with rugged commercial-quality gas chainsaws, leaf blowers, and string trimmers. As a battery-powered unit designed for residential lawn care, the FSA 80 R is different. The big question is whether or not Stihl’s battery equipment will uphold the tradition of rugged performance, reliability, and long working life.

Based on my experience testing it alongside a dozen other popular battery trimmers, the FSA 80 R is one of the best options in terms of trimming performance and offers adequate runtime for residential lawn maintenance. If you are looking for a strong and reliable battery trimmer that can trim and edge with precision or cut through an overgrown patch of weeds, the Stihl FSA 80 R battery trimmer is definitely worth considering.

Where to Buy the Stihl FSA 80 R Battery Trimmer

Get the Stihl FSA 80 R battery trimmer at:

• Northern Tool + Equipment for $399.99
• Stihl for $399.99

Meet the Tester

Mark Wolfe is a writer and product tester with an extensive background in the nursery and landscaping industry. For more than 20 years he mowed, edged, planted, pruned, cultivated, irrigated, and renovated beautiful landscapes. Now he tests and writes reviews about the latest outdoor power equipment, hand tools, lawn care products, and other outdoor living goods.