Karcher LTR 18-30 grass trimmer review

Lawn influencer and expert James Broadhouse takes the Karcher LTR 18-30 grass trimmer for a spin and sees how well it tackles a small to medium sized garden

Karcher LTR 18 30 grass strimmer laid on lawnrtimmer
(Image: © James Broadhouse)

Homebuilding Verdict

With a 2 year warranty (extended to 3 years if purchased directly from the manufacturer) and a tempting price point, the Karcher LTR 18-30 is an ideal tool for small to medium sized gardens that are kept in fairly good order and maintained on a regular basis. It is a real pleasure to use and has a good battery life of around 30 minutes which is enough to strim over 300 linear metres of grass. The battery is compatible with other tools in the range which is always a great feature if you enjoy buying in to one system or brand.


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    Easy to use

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    Karcher battery compatible

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    LCD battery indicator

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    Pre-loaded replacement strimmer spools

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    Wall mounted battery charger


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    Not for overgrown areas

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    Excessive automatic line feed

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Over the summer, I have been testing out the new Karcher LTR 18-30 grass trimmer. With the average garden in the UK being between 50–100m2 nearly all of us have to cut grass at one time or another. 

We all like a lovely striped lawn but how do we tame the longer grass around trees, pathways and under shrubs? Step forward the second most used garden power tool, the grass trimmer — or strimmer. 

Grass trimmers have been around for years and although the basic principle hasn’t changed much, the design and build quality certainly has. These days they are a lot more robust than they used to be and with the introduction of lithium battery technology, they are a lot quieter too.

Here I share the results and reveal why the Karcher Lawn Trimmer 18-30 sits up there as one of the best cordless strimmers currently on the market.

Lawn expert James Broadhouse beside Honda lawnmower in suburban garden
James Broadhouse

James Broadhouse has run a successful grounds maintenance and contract mowing business for over 15 years. Fondly known as 'Jimmy the Mower', James is an accomplished machinery reviewer and is fast becoming the industry go-to expert. 

We are not given any compensation by Karcher for our reviews, but may be allowed to keep the product, meaning we can test it over a greater length of time, and update this review if required.

The Karcher LTR 18-30 grass trimmer straight out of the box


Type: Cordless strimmer
Battery: 1 x 18V Lithium-ion Battery (2.5Ah)
Battery run time: 30 minutes
Charging time: 80 minutes
Weight: 3.5Kg
Working height: 95cm to 110cm
Cutting diameter: 30 cm
Line feed: Automatic
Other: Plant guard, tilt adjustment, rotatable head
Guarantee: 2 years

The Karcher LT 18-30 grass trimmer arrived in a sturdy and fully recyclable cardboard box which was emblazoned with plenty of photographs, so I was in no doubt as to what it was. 

The strimmer was packaged very well, and each part was protected during transit. My first impressions were that it looks a really sturdy and robust bit of kit but not too heavy which is always a plus point. 

It has a super strong adjustable centre shaft, a compact strimmer head with an impressive 30cm cutting diameter and an ergonomic handle which also houses the compact battery. There was also a comprehensive set of instructions in a handy booklet.

Karcher LTR 18-30 unpacked and laid out in garden

The Karcher LTR 18-30 is well packaged and comes with a comprehensive instruction booklet (Image credit: James Broadhouse)

The Karcher LTR 18-30 was easy to put together 

Before I could start to use the strimmer, there were a couple of simple assembly jobs to take care of but most importantly I had to charge the battery pack. 

The package I received included an 18v 2.5ah battery pack and a quick charger. The charger itself plugs in to any 3-pin electrical outlet and the battery slid on with a satisfying click. 

I knew the battery was seated correctly and was charging because the LCD display lit up and told me how many minutes were remaining until the battery was fully charged, what a great feature that display is!

Now I had got the battery on charge, I needed to fix on the strimmer guard, which is attached with 3 screws, and then I fitted the handle which is in turn secured with a single nut and bolt. All the hardware is provided, and the fitting is easy.

While the battery was still charging – it took approximately 70 minutes to go from 0%-100% – I grabbed a cuppa and had a quick flick through the instruction booklet to familiarise myself with the strimmer controls.

LCD display of Karcher LTR 18-30 grass trimmer

The integrated LCD display keeps you informed of battery level (Image credit: James Broadhouse)

Easy to manoeuvre and effortless trimming

With the battery fully charged and safely clipped into the handle I headed out to put the Karcher LTR to the test. I adjusted the centre shaft to maximum length and pivoted the adjustable head so that it would cut the grass evenly.

I pulled the trigger. The strimmer fired up straight away and with a reassuring whizz the line automatically fed out to the maximum length; seconds later I was trimming the grass. 

I was very pleased with how well balanced the strimmer was: even at full length and despite there being only one string line coming from the head it gave a surprisingly clean and efficient cut. 

I had to use minimal strength to guide the strimmer along and it effortlessly trimmed the grass against my raised sleeper beds. I was impressed. 

Close of adjustable centre grip on Karcher grass trimmer

An easy to operate adjustable grip allows user to change the height to suit (Image credit: James Broadhouse)

I then switched sides of the garden and proceeded to trim the grass adjacent to the porcelain tiled path, not something I would do with a larger petrol driven strimmer, but I was confident enough that the Karcher would do a great job without being too aggressive against the delicate tiles and guess what? 

It did a superb job of that too. Full of enthusiasm I zoomed round the other two sides of the lawn and the job was completed. 35 metres of trimming in a little under 5 minutes and with only 10% of the battery used. 

The Karcher LTR 18-30 grass trimmer in garden cutting edge

The automatic line feed makes sure that there is always enough line for clean cuts (Image credit: James Broadhouse)

Good battery life and great at edges

The manufacturer claims that the battery is good for around 350 linear metres of trimming, so I went round the outside again just to check it out. With less grass to trim I was even quicker this time and the battery still had 83% left. 

I headed over to my neighbour and offered to trim around the perimeter of both of his lawns (approximately 150m ) and he gladly accepted the offer. 

His grass was a little bit longer and tougher than mine, but I didn’t really notice the strimmer bogging down, however it certainly gave the battery a hammering, knocking it down to just 20% by the time I had finished. 

While in his garden I took the opportunity to test how the strimmer head can be adjusted through 90 degrees. If you squat down you can strim under benches, however, being a large chap, I didn’t find that a very easy or comfortable thing to do and I think in future, it will be easier to just move the bench. 

A feature that did come in handy though was the plant guard, not so much for lifting up and trimming under shrubs as shown in the pictures on the box, but for maintaining a safe distance for trimming around trees without damaging the bark.

Close up of Karcher grass trimmer head

The 30cm cutting diameter and plant guard make the Karcher ideal for most suburban gardens (Image credit: James Broadhouse)

It wasn’t all plain sailing though and I did at one point push the Karcher LTR beyond its capabilities by attempting to trim a patch of established stinging nettles, but even with a fully recharged battery it couldn’t take them down using just the string line. 

With that set back aside, I continued to use the Karcher LTR on my own lawn, trimming once a week and recharging the battery when it dipped below 50% which was every four weeks. It has continued to perform very well and although a little battery charge is lost between uses it is by no means excessive.

A pleasure to clean and simple to store

After all that hard work the strimmer certainly needed a clean down, so I grabbed a damp cloth and set about the task. It’s a pleasure to clean; the grass and weeds just wipe off the plastic shaft and guard and it is soon looking like new. 

I just had to be mindful not to catch the line trimming blade with the cloth or my fingers because it is razor sharp and tucked away in the corner of the guard.

With the strimmer cleaned and dried, it can be easily stored in a shed. It is light enough to be hung up on the wall or stored on a shelf, but also robust enough to stand up on its own without fear of it getting damaged by other machinery or daily activities. If space is at a premium, you can always shorten the shaft to make the unit more compact.

Top down shot of Karcher grass trimmer

The Karcher HTR 18-30 is easy to wipe clean and the height can be adjusted for easier storage (Image credit: James Broadhouse)

James Broadhouse

James Broadhouse has run a successful grounds maintenance and contract mowing business for over 15 years. He shot to fame in 2019 when a tweet about a local football pitch that he maintained went viral. James, who is fondly known throughout the industry as 'Jimmy the Mower', still runs his contracting business, however, he is gaining notoriety as an accomplished machinery reviewer and is fast becoming the industry go-to expert. 

In addition to testing out gardening products for Homebuilding & Renovating, mower machinery manufacturers and distributors as well as a host of tool companies use Jimmy to test products out in the field and appreciate his honest opinion and feedback. He also provides maintenance, servicing, and machinery user guide videos, many of which can be seen on his very own Jimmy the Mower You Tube channel , and on Homebuilding & Renovating.