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A powerful and well-priced cordless grass trimmer, the Stihl FSA 45 is the perfect choice for gardens with up to 250m of borders. With its PolyCut blades, the FSA 45 makes short work of even long grass and can tackle weeds, too. Despite the low price, the FSA 45 is light and flexible and offers height adjustment, handle adjustment and a rotating cutting head. An integrated battery means slightly more limited run-times, but for smaller gardens this won’t be an issue.


  • Very flexible
  • Powerful cutting
  • Extremely lightweight


  • Long(ish) charge times

Key features

  • Review Price: £99
  • Cordless strimmer
  • 1100 x 270 x 255mm, 2.4Kg
  • PolyCut Blade and optional line
  • 230mm cutting width
  • Rotating head

What is the Stihl FSA 45?

We’re used to seeing high-end tools aimed at professional and enthusiast gardeners from Stihl, but this grass trimmer is different. Priced at under £100, the Stihl FSA 45 is a cordless grass trimmer with an integrated battery, aimed at those with smaller gardens.

Powerful action, plenty of adjustability and excellent run-times make the FSA 45 the ideal tool for less demanding gardens, where a more powerful tool would be overkill.

Stihl FSA 45 – What you need to know

  • Handling – Very light and hugely adjustable, this grass strimmer is easy to wield comfortably and can tackle practically any job.
  • Grass cutting – Cuts easily through grass, leaving a neat cut; but go slowly on longer clumps of grass.
  • Weed cutting: Can cut through individual weeds easily enough but it isn’t ideal for thicker clumps or brambles; you’ll want a slightly more powerful grass strimmer for these jobs.

Related: Best grass trimmer

The Stihl FSA 45 design – It’s easy to set up and easy to adjust

It might be the cheapest cordless grass trimmer in Stihl’s lineup but you wouldn’t know it from the FSA 45’s look and feel. Decked out in the company’s traditional white and orange colour scheme, the FSA 45 is light (2.3kg) but has a reassuringly tough feel to it.

It’s also exceptionally practical. The shaft length can be adjusted (1100-1300mm), and you can adjust the main handle and cutting head to get exactly the angle you need. The result is a grass trimmer that’s exceptionally comfortable to hold no matter your height, stance or build. The head also turns for vertical cutting.

Stihl FSA 45 height adjustment

You can adjust the grass strimmer’s height, and you can change the angle of the handle to make it easier to hold

Underneath, there are two PolyCut blades rather than traditional strimmer line. These have been designed to provide a precision cut, and are easily replaceable thanks to the tool-free design that lets you unclip a broken one and slide in a new one. Stihl even provides storage for five more on the shaft, so you can swap out quickly when you need to. Replacements cost £8.99 for a pack of 12.

Stihl FSA 45 PolyCut blades

Dual PolyCut blades provide a clean method of cutting through grass

Stihl recommends soaking the blades in water before you use them, since this makes them softer and less likely to break when they hit a hard object. You can also use pre-cut mower line if you prefer, sourced from your local Stihl supplier.

Before use, the activation key – like a large car fuse – has to be inserted into the body, then the two comfortable hand triggers have to be pulled in to start the FSA 45. There’s just a single speed on offer.

Stihl FSA 45 controls

You have to press both buttons to start the trimmer, and the key has to be inserted

Stihl FSA 45 Performance – The strimmer works brilliantly on grass and lasts more than long enough for small gardens

The battery is pre-installed and as such the FSA 45 has to be charged with the power adapter plugged into the main body. From flat, a battery takes 3hrs 30mins to charge, although you can get to 80% in 2hrs 25mins. The battery then lasts for 20 minutes, which Stihl says is enough to tackle lawn edges up to 250m. This is plenty for for a small to medium garden.

A series of LEDs on the handle display the estimated charge left, so you can check as you go along if you’re nearing the end of your battery charge.

Stihl FSA 45 charge status

The LEDs show you how much charge the trimmer has remaining

I’m pleased to say that its estimations are pretty accurate, and the Stihl FSA 45 will last the distance on a small charge. Tackling a small garden with very long grass, as a result of it being left for two weeks in a combination of bright sunlight interspersed with torrential rain, the FSA 45 not only managed with the borders but had enough charge to shorten the grass to let the lawnmower through.

Performance is excellent, with the dual blades making shorter work of grass borders than then Gtech ST20, which uses a single plastic blade. When faced with larger clumps of long grass, the FSA 45 would occasionally jam. But a slower cutting movement, tackling fewer blades of grass at a time, always fixed the issue.

Stihl FSA 45 at work

The grass trimmer makes short work of lawns

When dealing with weeds thicker than a pencil, the FSA 45 took a bit of time to cut through – but it  did the job without complaint. However, I found that I needed to tackle weeds individually; thicker clumps of weeds or brambles proved a little too much for this model. For those jobs you’ll want a brush cutter or grass trimmer that offers more power – as well as, potentially, a selection of cutting heads, such as the Stihl FSA 56.

For dealing with tree trunks and more delicate plants, there’s a fold-down metal guard, so you can get up close and personal without cutting something you shouldn’t – or snapping a blade. In all cases, the lightweight body made the FSA 45 a pleasure to use and I never tired while holding it.

Stihl FSA 45 plant protector

The protector stops you cutting where you don’t want to go

Should I buy the Stihl FSA 45?

As always with this type of product, usage is the guiding factor as to whether this is the right grass trimmer for you. If you have a small garden (less than 250m of borders) and want to deal mostly with grass and the occasional weeds, the Stihl FSA 45 comes highly recommended. It’s excellent build quality, brilliant performance and ease of use make this a great-value grass trimmer.

In fact, for most jobs, the FSA 45 is better than the similar Gtech ST20, which has only a single blade. Gtech’s advantage is that the ST20 has removable batteries, so you can extend run-time by switching out one battery for another, and it’s useful if you have other Gtech kit that takes the same batteries.

That said, if you need something with greater power, you don’t get better than the Stihl FSA 56, which has replaceable batteries and works brilliantly. This is a particularly good choice if you have another Stihl product that uses the same batteries, such as the excellent Stihl RMA 235.

None of the alternatives take anything away from the Stihl FSA 45: it isn’t just the best value grass trimmer we’ve tested; it’s the best trimmer for small gardens without a doubt.


Size (Dimensions)
First Reviewed Date
Model Number
Cutting width
Strimmer type
Adjustable length
Cutting tool
Rotating head

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