Anthbot M9 Review – Trusted Reviews

Introduction

With robot lawn mowers becoming increasingly popular as a hands-off way to keep your garden in check, the Anthbot M9 arrives with a spec sheet that sounds genuinely impressive.

It promises to tackle lawns up to an acre in size, handle slopes of up to 45%, and ditch the need for physical boundary wires altogether thanks to its GPS- and 4G-based navigation system. Throw in AI-powered obstacle detection and automatic mapping, and it certainly sounds like a smart solution for anyone after a stress-free mowing experience.

But, as is so often the case with robot mowers, the real test isn’t what it can do on paper – it’s how well it copes with the quirks of an actual garden. 

After spending time setting up and using the Anthbot M9 in my own admittedly less-than-perfect garden, it became clear that while there’s plenty to like here for the right kind of garden, there are more than a few frustrations that stop it from being an easy recommendation.

Design and features

• Docking station for charging
• Dedicated GPS RTK station
• Automatic or manual control

The Anthbot M9 might have an impressive feature set, including mowing lawns up to an acre in size and handling slopes of up to 45%, but it does need a bit of setup before it can crack on with the job at hand.

You might feel a bit overwhelmed with the number of parts in the box, but it’s actually pretty straightforward to set up. The first step is to mount the charging base along the edge of your grass and use the included screws to secure it to the ground, with the caveat that it needs a clear view of the sky, so it can’t be near buildings or trees. 

That can be a bit of a struggle depending on your garden and placement of any outdoor plugs, as the cable, even with the extension attached, isn’t that long at 10m. And, if you order it in the UK, be aware that it comes with an EU plug, so you’ll need to get an adapter or rewire it yourself.  

I actually had to place mine on a brickwork patio due to the placement of my outdoor plug, though it had no real impact on the performance – the M9 simply made its way to the grass before activating the blades.

There’s also the GPS-based RTK station that helps the mower stay on route, though, thankfully, it comes with an extension cable (which has to be plugged into the charging dock rather than an outlet) to keep it out of the way. It has a pretty stable base that can be pushed into grass or soil, but it can be a bit of an eyesore with a rather industrial look and bright green LED; it’ll depend on your garden’s style, I suppose. A lot of new robots dispense with this reference station, using network RTK for navigation, as with the Segway Navimow i205 AWD.

Just don’t do what I did and move the RTK station post-setup, as you’ll need to go through the initial setup in the app once again. 

When it came to the robot itself, there was very little involved; I just had to move it into place on the charging station to start charging. I will say, though, without any dedicated carrying handle like the LawnMaster OcuMow 18 Autocharging Vision – and stickers explicitly telling you not to hold the mower by the wheel covers, which is where you’d naturally grab – it can be a bit big and bulky to move around. Still, it’s not impossible, and I got cracking with the Anthbot app setup soon after. 

During the setup process, you’ll be able to get the M9 to automatically map your garden, something possible thanks to its combination of two 150-degree HDR cameras – though you’ll need pretty distinctive borders for this to be a success. 

I thought my garden would be perfect, with two grassy areas distinctly separated by a brick path and 1-ft fences protecting the flowers, but it really struggled. After letting it do its thing, it came back with a completely inaccurate map, missing chunks of my grass.

Thankfully, you can set the boundary yourself by taking manual control of the mower and driving it around the edges of each area – but even this is a little finickier than it has to be with, in my experience, overly sensitive joystick controls that make it go very fast with only slight adjustments. 

Once done, I renamed each area (on the off-chance I wanted to mow one area one day, and the other the next) and added a no-go zone around a pergola pillar that sits in the corner of my grass. There’s no need for any physical boundary lines here though, a refreshing change from plenty of robo mowers. 

Once setup was complete and the GPS was active, I was free to activate the M9 and unleash it on my garden – but I’d recommend changing a few features in the app first. The biggest is to set the cutting height, with the M9 offering a range from 30- to 70mm, in pretty precise 5mm increments. 

The electronic system used here is much more convenient than having to adjust a manual selection wheel on the mower itself, as it can be done from anywhere. It just makes it that little bit easier to adjust the height of your grass – you’ll typically want it longer in the spring months before cutting it down shorter in the summer. 

You can also set a schedule to mow the grass automatically, and with the M9 able to detect rain and stop mowing to avoid damaging the grass, it shouldn’t make a mess of things on rainy days either. 

The default mowing mode seems quite random, with the M9 going in different directions depending on the shape of your grass – but you can set the direction if you want those professional-looking lines. You can also get it to mow the lawn twice on every run, just to ensure you’ve caught every single blade of grass.  

You can also trigger the M9 using the buttons on the mower’s control panel, with different button combinations allowing you to mow or return home, along with a big stop button to stop the mower in an emergency. This is also where you’ll find the battery key, which is essentially a kill switch – take it out when you’re not mowing, and it simply won’t work. That’s great if you’ve got curious kids around, though it also means you won’t be able to remotely trigger it. 

Flip the robot over, and you’ll see a 20cm wide cutting deck with five replaceable razor blades that spin around to cut the grass. That’s a pretty wide base, and the use of five blades instead of three is another welcome upgrade compared to some of the cheaper options floating around. It is still on the small side if you’ve got a 1-acre lawn, but it’s fine for my relatively compact suburban garden. 

Performance

• Clean, uniform cuts
• Can miss areas of grass
• Goes outside its boundary lines
• Can’t handle lumpy ground at all

With advanced features like the ability to navigate 45% slopes, a wide cutting blade and a 150-degree camera to understand the world at hand, I had high hopes for the Anthbot M9 – but still, letting it go on my precious lawn for the first time was daunting. 

It’s not a perfect lawn by any means – the shrink-swell clay soils of my ground mean it’s quite lumpy and bumpy in places, and there are a few patches of dying grass – but it’s pretty healthy and neat-looking overall. 

Letting the M9 go the first time, it started in a random patch in the middle of the grass before dotting here, there and everywhere, with the blades turning on and off frequently. It did this, I realised, when it detected any particularly high lumps in the grass – I imagine in an effort to stop scalping the grass – but it also meant that chunks of grass were left essentially untouched. 

Then there was the opposite problem; when the M9 detected a divot a little too steep, it’d stop, bleep angrily for a few seconds, and then turn away. It did occasionally try these at different angles, but usually it’d be the same story: stop, bleep, give up.

The problem is that there’s no indication as to what this bleep actually means, and there’s no notification or information about it in the app – I only figured it out by sheer trial and error. I tried filling some of the divots with dirt to reduce them, but it seems very sensitive in this regard. It can handle 45% slopes, sure, but they’d better be smooth slopes. 

It’s also not that great at detecting objects, despite the fact that it’s designed to be able to detect over 1000 objects, including people and animals. There were multiple occasions when it simply rammed into the 1ft fences that protect my flowerbeds; it didn’t go any further, thankfully, but considering I stayed away from them in mapping, it was surprising to see. 

That wasn’t the only time it went over the boundary line either; it also got stuck on a mini kerb in one corner of my grass that I purposely avoided mapping as it attempted to essentially cut the corner. 

When it gets stuck, it bleeps constantly, but again, there’s no notification sent to your phone to alert you to this if you’re not nearby. I also found that the blades and wheels didn’t stop spinning despite grinding against the stone kerb, something that’s particularly worrying from a safety standpoint. 

Essentially, it’s something you won’t want to leave unattended – and that kind of defeats the purpose of having a robot lawn mower. 

It does a much better job at detecting humans at least; whenever I’d walk in front of the M9 in use, it’d turn away and head in a completely different direction. 

Anyway, back to the cuts; I found that it’s very hit-and-miss in terms of coverage. The first few runs, it got the majority of the grass, but on the latest run, it simply seemed to forget around a third of one of my zones. Looking in the app, it said it had covered it – I’m not sure what happened there. 

You can take manual control of the robot to get it to cover any areas it might’ve missed, but as mentioned earlier, the controls are very sensitive, making it difficult to maintain a straight line and navigate bends cleanly.

I think it also struggled in my garden due to the wheel design; the big rear wheels deliver plenty of power to get it up those inclines, but the shopping trolley-style front wheels offer no direct control, and it means that those bumps in my grass can often send it to the left or right of where it wants to go. 

It also doesn’t handle edges very well – the 20cm blade doesn’t extend to the edges of the mower, after all – but that’s a criticism of most robot mowers. It does have an edging mode that you can activate in the app, where the robot will run along a border; however, if the M9 is up against a fence, it still won’t reach. You’ll likely need to go out with a strimmer to tidy those up every now and again. 

It isn’t all bad, of course. The combination of a wide cutting blade and five blades means that when it cuts, it does so neatly and efficiently. You can see clear paths being made as the M9 makes its way through taller areas of lawn, and the cut height is pretty uniform (aside from the aforementioned bumps). The areas it did manage to cut properly looked great – it’s just a shame it wasn’t a uniform experience for me.  

That said, it feels like you need a golf course-level of flatness and clearly defined edges to get the most out of the M9 – and most of us don’t have that in our gardens. If you’ve got a lumpy, bumpy garden like me, you’d likely be better served by something like the Sunseeker Elite X5. 

The one saving grace is that the M9 doesn’t struggle to find its way back to the docking station once it considers the job done; even with the placement of the base station away from the grass, it makes its way over and docks itself first-time most of the time. 

Should you buy it?

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