I tested the Stihl RMA 239 Cordless lawn mower - it's a winner for small lawns with little storage space

The Stihl RMA 239 Cordless lawn mower is a battery-powered mower designed for small to medium-sized lawns, perfect for homeowners looking for a quiet and efficient mowing solution. With a 37 cm cutting width and a 40-litre grass collection box featuring an easy-to-empty catch mechanism, this lightweight mower offers convenience and performance in one package. It also boasts six cutting height settings ranging from 20 to 70 mm, giving you lots of options when cutting.

I tested this lawn mower in July in warm conditions on a dry lawn, evaluating its cutting quality, manoeuvrability, and battery performance to see how it measured up to the best lawn mowers in our buying guide. I also checked out how user-friendly it was to set up and operate, paying particular attention to its folding mono-handlebar design for easy storage.

Find out how the Stihl RMA 239 Cordless lawn mower performed during testing and learn more about its features, such as the easy-adjustment cutting height scale and height-adjustable handlebar. I'll also share a few tips on maintaining this cordless mower.

Stihl RMA 239 Cordless lawn mower specifications

• Suitable for: Small to medium lawns 
• Power: Cordless (battery-operated)
• Cutting options: Cut & Collect 
• Deck material: Plastic
• Weight: 16kg
• Dimensions: 53 x 41 x 79cm (H x W x D)
• Cutting width: 37cm
• Cutting height: 20mm to 70mm (6 cutting heights)
• Battery life: Around 40 minutes
• Grass collector: 40L
• Decibels: 91 dB
• Warranty: 5 years
• Charge time: 135 min for 80%, 180 minutes 100%.

Who tested this lawn mower?

Joanne Lewsley

I regularly test home and garden products for UK and US websites, including Ideal Home, Top Ten Reviews, and Live Science, evaluating the quality of home and garden gadgets by putting them through their paces in a natural home environment. 

I tested the Stihl RMA 239 Cordless lawn mower on a small grass lawn measuring 12.5 square metres (134 square feet) in dry conditions in mid-summer. 

Unboxing, setting up and first impressions

The Stihl RMA 239 Cordless lawn mower arrives in a large cardboard box cushioned with additional cardboard and minimal plastic packaging to ensure safe transit. The packaging is mainly eco-friendly, with the box and thick cardboard inserts being recyclable.

The mower comes partially disassembled in two main components: the handlebars and the mower body. Assembly requires attaching the handlebar to the main unit. This process can be challenging to manage alone, as it involves simultaneously holding the handlebars in place while fitting washers, screws, and nuts. Due to the fiddly nature of this task, we’d recommend you have an extra pair of hands available during assembly to make this a bit smoother and less frustrating.

Adjusting and folding the handlebar is straightforward. To adjust the handlebar, place the mower on a level surface, then grip the handlebar. Press the adjustment lever downwards and hold it while moving the handlebar to the correct position for your height, then release the lever and make sure the handlebar locks securely into place.

You can also fold the handlebar for compact storage or easier transport. Again, with the mower on a level surface, press and hold the folding lever. Then, simply fold the handlebar forward over the body of the mower. This feature is handy if you have limited storage space in your shed or garage.

The Stihl RMA 239 Cordless lawn mower also has a roomy 40L grass clipping collector. It’s super easy to attach to the back of the mower, and it features a very simple but clever mechanism - a grass level indicator on the top of the box that drops down so you know exactly when to empty it.

So much easier than a window that often gets covered in damp grass! However, unlike other cordless mowers, such as the Husqvarna Aspire LC34-P4A, it doesn’t fold down, so you’ll have to consider that when working out your storage.

The Stihl RMA 239 is powered by an AK 20 battery, which you can purchase with your mower or separately. The battery is also designed to work with a wide range of Stihl power and garden tools, so if you’re a Stihl fan, you may already have one in your garage or shed. My lawnmower came with the battery and an AL 101 charger.

The battery was already 30% charged, so it only took an hour or so to charge before I was ready to mow. Inserting the battery is straightforward: lift the tab to open the flap to the battery compartment, slide the battery into the compartment until you hear a click, and close the flap.

The battery provides enough power to mow an area of up to 250m² on a single charge. This should be sufficient for most small to medium-sized lawns. For those with larger gardens or who prefer extended runtime, the mower is also compatible with other batteries in the AK series, such as the higher-capacity AK 30. Or you can purchase a package that includes two AK 20 batteries, doubling your mowing capacity to around 500m² and allowing you to tackle larger areas without interruption by simply swapping out the batteries when needed.

Without charging the battery, unboxing, assembling and setting up for the first use takes around five to ten minutes, which is quick.

When you flip the Stihl RMA 239 over, you'll see the cutting blade underneath. Stihl calls this a 'Flow-optimised' blade. They say it cuts through the air better, which means the motor's power goes more into cutting grass and less into fighting air resistance. This clever design helps the battery last longer.

The blade cuts a 37cm wide path as you mow. This width is just right for small and medium-sized lawns. It's wide enough to get the job done quickly but not so wide that it's hard to steer around garden obstacles or squeeze through tight spots.

The Stihl RMA 239 Cordless lawn mower features quite an unusual handlebar design, with just one arm connecting to the main unit of the mower. However, this doesn't affect stability or ease of use at all. It’s also brightly coloured with pops of Stihl’s trademark orange, black and white. The fold-down handles are also great for compact storage. It’s not the lightest of mowers, at 16kg, but the lifting handle helps make it reasonably easy to lift and store away.

Ease of use

The two-point starting mechanism is easy but designed for safe use; simply press the locking button and pull the control bar towards the handlebar to start the mower. When you release the control bar, the mower automatically stops.

There are six cutting heights ranging from 20mm to 70mm. For the first mow, I chose cutting height four, which is 60mm, followed by cutting height two (40mm). Switching between each cutting height using the black lever on the main unit is easy and quick.

I was impressed with the performance of the Stihl RMA 239 lawn mower. It handled my lawn efficiently without any interruptions, delivering a neat trim. The 37 cm cutting width was perfect for navigating my small garden, making it easy to manoeuvre around obstacles and reach tight corners.

The mower excelled at creating clean edges where the lawn met my patio, leaving a crisp finish. I was particularly pleased that there was no need to sweep up stray clippings from hard surfaces afterwards, as the mower did an excellent job directing all clippings into the collection box.

The 40L grass collection box was more than enough for grass clippings from my small lawn. After completing my first mow, it was only about half full, which suggests it would also be suitable for larger lawns. This is a definite plus if you don't want to interrupt your mowing to empty the box frequently.

While the Stihl RMA 239 doesn't have a mulching facility, I didn't find this a significant drawback, given how effectively it collected the clippings. The overall finish of the lawn was impressive – neat, uniform, and visually appealing.

One of the standout features of this mower is its relatively quiet operation at around 85 dB. You could easily mow your lawn without worrying about disturbing your neighbours.

If I had to point out any minor improvements, a built-in cleaning tool for the cutting deck would be handy. However, this is a minor consideration given the overall quality and performance of the Stihl RMA 239 lawn mower.

Cleaning and maintenance

Stihl recommends a simple cleaning routine after each use. Start by switching off the mower and removing the battery for safety. The main body of the mower can be cleaned with a damp cloth. Use a soft brush or a damp cloth to remove any grass clippings or residue for the discharge chute.

Pay special attention to the battery compartment. Remove any debris and wipe it down with a damp cloth. Clean the electrical contacts in this compartment carefully using a paintbrush or a soft brush to ensure good connectivity.

Carefully tilt the mower on its side to thoroughly clean the cutting area. Clean around the blade and the blade itself using a stick, soft brush, or a damp cloth. Be careful when handling the blade area.

Clean the battery with a damp cloth, and for the charger, unplug it first, then wipe it down with a damp cloth. The charger's vents and electrical contacts should be cleaned with a paintbrush or soft brush to prevent dust buildup.

Stihl strongly advises against using high-pressure cleaners or water jets, which can damage the mower's components.

Regularly checking the blade for damage or dullness is also generally good practice. Have a professional sharpen or replace the blade to maintain cutting performance if needed.

How does it rate online?

The Stihl RMA 239 lawn mower enjoys good user ratings, with a five-star rating on farming and gardening supply site Sam Turner & Sons. Users really like the Stihl RMA 239 lawn mower. They say it's light and easy to use, making mowing less of a chore. One user comments, 'This lawnmower is everything I could wish for. Lightweight, easy to manoeuvre and cuts well. The battery lasts long enough to cut both my medium-sized lawns and is simple to remove for recharging.' People also love how it folds up for easy storage.

Happy customers report the mower does a good job collecting grass and emptying the grass box is simple. They say it’s well-made and quieter than many other mowers. While one thought it was a bit expensive, they still felt it was worth the money. Overall, most people who bought this mower seem very happy with it.

Should you buy the Stihl RMA 239 Cordless lawn mower?

The Stihl RMA 239 is an excellent choice for anyone seeking a reliable, efficient cordless mower for small to medium-sized lawns. From assembly to operation, it's user-friendly and lightweight enough to manoeuvre easily around your garden. The cutting quality is impressive, delivering a neat finish every time.

One of the standout features is its battery life, which is sufficient for most small to medium lawns and can even handle multiple mows on a single charge. The 37cm cutting width perfectly balances efficiency and manoeuvrability, making it ideal for navigating garden obstacles.

The Stihl RMA 239 is also an excellent option for those with limited storage space. Its folding mono-handlebar design allows for compact storage, and the easy-to-remove grass collection box adds to its space-saving qualities. While it doesn't have a mulching option, the efficient grass collection system means you won't have to worry about cleaning up clippings afterwards.

The mower's quiet operation is another plus, allowing you to mow without disturbing neighbours. While it may be pricier, the quality of construction and performance justify the investment. The compatibility with other batteries in the Stihl AK series adds to its versatility and value.

If you're looking for a cordless mower that combines ease of use, excellent cutting performance, and smart design features, the Stihl RMA 239 is worth considering. It's a solid choice that should meet the needs of most small to medium lawn owners.