Best Robot Lawn Mower Guide

The Best Robot Lawn Mowers (Comparison And Review)

So you’re thinking about buying a robot lawn mower but are unsure which model to buy.

I was in your situation when I first started learning about robot lawn mowers. With so many models available, confusing specifications and model names that seem to make no sense, you might need a bit of help.

Good News: This article will help you to identify the best robot lawn mower models on the market today, as well as explain the main features that you should consider.

The recommendations in this article are the result of hundreds of hours of research and real world testing, and tens of thousands of hours of real world use, from myself and a number of contributors to this website. I feel that each recommendation provides the best performance for the price in each lawn size category.

The First Thing To Consider Is The Size Of Your Lawn

The size of your lawn is one of the most important factors when choosing a robot lawn mower, so I have divided my recommendations into 7 different lawn size categories. Once you have worked out how big your lawn is, you can focus on the models that are most suited for this size of lawn.

The first section of this article provides my recommendation for the best robot lawn mower at each lawn size category. I then go into detail about all the main features and provide a comparison between different robot lawn mowers. Hopefully this will help you determine what the best robot lawn mower is for your particular circumstances. 

Lets Get Started: Here are my choices for best robot lawn mower of 2019.

Best for lawns up to 400m² – Flymo 1200R

Flymo 1200R Robot Lawn Mower

The Flymo 1200R is suitable for lawns of up to 400 m² and has an excellent balance of features for a really competitive price. For those with a smaller garden, who don’t want to spend more than is necessary on a robot lawn mower, I think that this is the best robot lawn mower for you.

The Flymo brand is owned by Husqvarna, one of the giants in the world of robot lawn mowers. As a result, it is very similar to the Husqvarna 105, which can manage lawns of up to 600m², but costs twice the price. I have personally used the Flymo 1200R for two years and have been delighted with it. It’s usually one of the best value robot lawn mowers and I’d highly recommend it. Check out the customer reviews of the Flymo 1200R on Amazon and see the current price. 

It lacks smart features and doesn’t do as good a job on your edges as some other brands, but the core functionality is excellent at an unbeatable price. Read my full review of the Flymo 1200R here. 

Best For Lawns Between 400m² and 600m² – McCulloch ROB R600

McCulloch ROB R600 Robot Lawn Mower

The McCulloch ROB R600 is designed for slightly larger lawns, and follows on closely from my last recommendation. It is able to manage lawns of up to 600 m², and has great core functionality to manage your lawn really well without any human intervention. The McCulloch brand is also owned by Husqvarna and you can see a lot of similarities between this model and both the Flymo 1200R and Husqvarna 105.

Where the McCulloch ROB R600 wins is on the balance between cost and features. Again, it is targeted at the more cost-conscious buyer, but if you are looking for an excellent robot lawn mower at a very reasonable price, then you cannot go wrong here. Check the current price of the McCulloch ROB R600.

Spares, repairs and customer service are also excellent due to McCulloch being part of a larger company. For lawns of this size, I think the Husvarna 105 offers no better performance for a lot more money. Other competitors such as the Robomow RX series are quite expensive and have a few critical flaws, and the Worx models struggle to compete on price and performance.

There are a number of other brands in what is a fairly crowded segment of the market, but I don’t think the McCulloch ROB R600 can be beaten at present. There is also an R1000 model that can manage lawns of up to 1000 m² which is a solid choice also. Click here for a full review of the McCulloch ROB R600.

Best For Lawns Between 600m² and 1000m² – Robomow RC304u

Robomow RC304u Robot Lawn Mower

For slightly larger lawns, I think the Robomow RC models are an excellent package, and the RC304u in particular, hits a sweet spot for price and performance. For a fairly competitive price, you get access to some of the great features that Robomow have in their mid-range robot lawn mowers.

The Turbomow feature makes longer grass effortless and the smart features are both functional and great fun. The edge mode does a much better job of edge cutting than other competitors. The Robomow RC304u has a wider cutting diameter than most other robot lawn mowers in this price range, reducing the time it takes to cut your lawn. The negative of this is that it has higher power consumption and shorter working time per charge.

The Robomow RC304u is also a fair bit louder during operation than many of the competitors in this category. The Husqvarna 310 and the McCulloch ROB R1000 are both worthy competitors in this segment, but the combination of features of the Robomow RC304u make it the best robot lawn mower if your garden is between 600m² and 1000m². I have written a full review and installation guide for the Robomow RC304u here.

Best For Lawns Between 1000m² and 1500m² – WORX WR153E L1500

Worx have a lot of robot lawn mowers available for smaller gardens and they are all reasonably good, but it is not until we get to the models designed for slightly larger gardens where I feel they can compete on both features and price. The WORX WR153E L1500 matches the performance of the Robomow robot lawn mowers, but does so with quieter operation and at a cheaper price.

The main competition is the Robomow RC308u and the Husqvarna 315. I was particularly impressed with the navigational ability of the WORX WR153E L1500. Worx have a patented AIA artificial intelligence system which improves the efficiency with which your lawn is cut, and improves its ability to pass through narrow stretches of your lawn.

Choosing the best robot lawn mower for this size of lawn was tough as there is great competition, but the WORX WR153E L1500 comes out on top. Check the current price of the WORX WR153E L1500 and read customer reviews on Amazon.

Best For Lawns Between 1500m² and 2500m² – Robomow RS615 Pro X

Robomow RS615 Pro X Robot Lawn Mower

For lawns above 1500m², most manufacturers are starting to throw everything they’ve got into their models to compete with the competition. The Robomow RS Royal line of robot lawn mowers is pretty impressive all round. It has one of the widest cutting decks of any robot lawn mower, ensuring very fast and efficient cutting of your lawn. 

At this size of garden, we have another entrant, the John Deere Tango E5, which is another excellent product, but just can’t quite match the superb performance of the Robomow RS615 Pro X.

For lawns of between 1500m² and 4000m², I think Robomow have the best robot lawn mower offering, and are able to produce it at a very competitive price. 

Best For Lawns Between 2500m² and 4000m² – Robomow RS625 Pro

Robomow RS625 Pro Robot Lawn Mower

The Robomow RS625 Pro is essentially an upgraded version of the previous recommendation. It does a brilliant job of maintaining your lawn in a freshly cut state with no human intervention. The cutting system of the RS range uses a pair of counter rotating, solid blades which are able to handle anything that it thrown at them.

Slope performance of the Robomow RS line-up is a slight chink in the armour, as they can only manage a slope angle of 20 degrees, versus the 25 degrees of the very best performer, the Honda Miimo 3000. The extensive dealer network, parts availability and accessible customer support help to give the Robomow models the edge.

I surprised myself a little when I didn’t pick any Husqvarna robot lawnmowers in my top choices, as they are one of the major companies in the sector. Their robot lawn mowers are excellent and you couldn’t fail to be happy with any of their products.

For larger gardens, if the pricing was equal, it would be a very tough call to pick the best robot lawn mower between Husqvarna and Robomow. For now, though, I would definitely give the Robomow offerings the nod. Click here to find read more about the Robomow RS625 Pro – Full review. 

Best For Lawns Larger Than 4000m² – Ambrogio L250i Elite S Plus

Ambrogio L250i Elite S Plus Robot Lawn Mower

In the biggest lawn size category, I have chosen a model from Ambrogio. This was essentially a three horse race between the Husqvarna 450X, the Robomow RS 635 Pro SX and the Ambrogio L250i Elite S Plus. Ambrogio have a number of models available for smaller gardens, including one for very tiny lawns which is the only model available that does not require installation of a perimeter wire.

However, Ambrogio’s larger models are where they really shine. They also have models that can manage much larger areas of grass, including the L400 elite, which can manage up to 30 000m2 and can work for 11 hours at a time. The performance and features of Ambrogio’s larger models are really impressive, and certainly for any lawn over 5000m2, I would struggle to recommend anything else.

With a lawn capability of up to 5000m2, the Ambrogio L250i Elite S Plus will do a brilliant job. It has the longest cutting time of any of its competitors and the navigational ability is excellent.

Our Experience

We have spent hundreds of hours testing and researching robot lawn mowers and have thousands of hours of real-world use. We have spoken to all the major manufacturers to gain a complete understanding of the robot lawn mower market.

We do not discuss every robot lawn mower for sale in this article. If a model is not mentioned, its because it did not meet our shortlist of candidates to consider for our top recommendation. I don’t believe that you will find a more complete resource online to help you research robot lawn mowers.

Who Should Get A Robot Lawn Mower

Robot lawn mowers are still regarded as a niche choice for lawn care. They have been available for domestic use for over 20 years, and for commercial use for even longer. The technology has developed slowly and steadily and the cost has slowly reduced.

The market for robot lawn mowers is increasing rapidly and is forecast to grow at between 17-20% per year between 2018 and 2025. As a result, I think that robot lawn mowers are now becoming a mainstream option for lawn maintenance.

Robot lawn mowers are best suited to people who live in a property with a lawn in one or two main sections. The more fragmented your lawn, the less benefit you will get from purchasing a robot lawn mower. Robot lawn mowers can now manage lawns of considerable complexity and they generally have good ability to manage slopes.

There are two main downsides of robot lawn mowers. Firstly, they require installation of a perimeter wire and this can take several hours if you have a large and complicated garden. Secondly, even the best robot lawn mower will not cut the edges of your lawn perfectly.

There are some models that do a really good job and will be able to manage the edges of some gardens. However, for most people, you will have some edge maintenance to do. If you do not want to have any input in caring for or maintaining your lawn, you may want to stick with a gardener for a while yet.

How We Picked

When considering the best robot lawn mower to pick for each size of lawn, I wanted to pick the model with the best overall performance at maintaining a lawn. However, I wanted to ensure that each pick represented good value for money. There are many models available that compete very closely on features, but there can be a considerable difference in pricing. For this reason, pricing had more of an impact on my choices than I thought it would.

Where I feel a robot lawn mower model is sufficiently better than the competition to justify a higher price, I have included it.

How Good Are Robot Lawnmowers?

There are no perfect robot lawn mowers yet, so our recommendations are of the best robot lawn mower available currently at each lawn size category. The main drawbacks are the installation process and the limited ability to fully maintain the edges of a lawn. Edge cutting ability is improving with every new model, but there has been very little sign of a solution to the perimeter wire issue. There is only one robot lawn mower currently available that does not use a perimeter wire to navigate around a lawn. This is the Ambrogio L60 Deluxe.

Whilst the Ambrogio L60 Deluxe is to be applauded for trying something new, the drawbacks mean that I cannot recommend it. The main negatives are that it will only work on lawns with very specific lawn characteristics, and it will not charge automatically.

You need to charge it manually and then it will work for up to 2 hours, before stopping when it runs out of battery. It is only suitable for lawns of up to 200m². There are much better alternatives from a range of companies and for a small lawn of less than 200 m2, the time to install a perimeter wire would be very short indeed.

Things You Should Think About When Considering A Robot Lawn Mower

The next section of this article will discuss all the major features and aspects of robot lawn mowers which you should think about before making a purchase. It’s better to think now, and choose a suitable model, than to purchase something that is less suitable for your needs.

Installation Process

The installation of almost all robot lawn mowers is a fairly time consuming process. This is due to the need to install a perimeter wire around the border of your lawn and any obstacles within your lawn, such as flower beds or ponds. There is only one robot lawn mower currently available to buy that does not require the installation of a perimeter wire. This is the Ambrogio L60 Deluxe. However, it has some major drawbacks and you need to be very sure that it will work on your particular lawn setup before deciding to purchase it.

Thankfully, installation of a robot lawn mower only has to be done once, and after it is done you can look forward to effortless lawn maintenance from your robot lawn mower. The main things to think about with the installation process of a robot lawn mower are as follows;

Access To A Power Supply

You must be able to run a low voltage power cable from the charging station to a suitable power source. If you have an outside power source, this will need to be within the range of the supplied power cable. Alternatively, it is usually possible to buy longer power cables from your supplier.

If you do not have an external power socket, it may be practical to run a cable from an inside power socket. I have seen people run the power cable through a ventilation duct to access an internal power source quite successfully. Alternatively, it may be an opportunity to get an external power socket installed. The best location for an external power socket is within the garden itself, rather than attached to the external wall of your house. The reason for this is that the power cable will not have to cross any path or patio on the way to your lawn.

Charging Station Location

Most manufacturers provide guidance about where to install the robot lawn mower charging station. Note that most manufacturers advise installing the charging station on the edge of your lawn, not on a path or patio. This was something that initially took me by surprise when I first purchased a robot lawn mower. I originally planned to install the charging station next to the external wall of my house, where my external power socket is. After realising my mistake, I installed the charging station on the edge of my lawn and ran the power cable across a short section of path to the power socket and used a rubber cable management strip to keep the cable from being a tripping hazard.

In a subsequent installation, I was able to ensure that a power socket was installed at the edge of a flower bed next to my lawn. This ensured that the cable from the charging station was right next to the power socket and there was no cable getting in the way.

There is very little difference between the individual manufacturers and models in terms of the charging station location advice. You must have 1-2 metres of flat grass in front of the charging station to ensure that the robot lawn mower will be able to enter and exit from the station without any problems. You should place the charging station on a flat section of grass to minimise the risk of the robot lawn mower losing traction when it is entering or exiting the charging station.

If your lawn has a major slope, you should put the charging station on the lower level. This will ensure that when the robot lawn mower returns to the charging station in a low battery state, that it is able to reach the charging station without any problems.

Perimeter Wire Installation

robomow rc304u perimeter wire installation

The majority of the installation time will be spent placing and securing the perimeter wire. This wire will carry a low voltage electromagnetic signal which the robot lawn mower will use to detect the edge of the lawn. The perimeter wire can either be pegged to the ground or buried several centimetres under your lawn. Installation of the perimeter wire is fairly standard across all manufacturers and models, with only minor variations. The distance that the perimeter wire should be installed from the edge of your lawndoes vary a little from manufacturer to manufacturer. It also usually varies depending on what your lawn borders with. Typically the perimeter wire is installed slightly further from the edge of your lawn when it meets a fence or wall, and much closer to the edge of the lawn where it meets a path or patio.

Guide Wire Installation

In addition to a perimeter wire, some brands of robot lawn mower also require the installation of a guide wire. This is a wire that runs up the middle of your garden and assists your robot lawnmower in locating the far side of your lawn and to access difficult to reach areas. It also assists the robot lawn mower in finding it’s way back to the charging station.

There are several brands of robot lawn mower that do not require the installation of a guide wire. Two examples, Robomow and Worx, use the perimeter wire to assist with navigation back to the charging station instead. As a result, the installation of robot lawn mowers from these manufacturers tends to take a little less time.

Initial Start Up And Calibration

I think all the major manufacturers do a good job of guiding you through the first start up and calibration process. Most models guide you through this process via the control panel and provide fairly clear supporting documentation in the manual. I was particularly impressed with Robomow in this regard, who have an excellent YouTube channel with videos that provide great guidance in the installation and initial start-up process.

Cutting Height

Most robot lawn mowers have good options to adjust the cutting height of the blades. Many models are able to cut your grass to a length of between 20 and 60mm. A number of models do you offer lower and higher cutting heights. If you prefer your lawn to grow longer, which is common with warm weather grass varieties, you may want to look at models such as the John Deere tango E5, which has a maximum cutting height of 102mm.

At the lower end of the cutting height scale, the Robomow RC range has a minimum cutting height of 15 mm. For the vast majority of people, any robot lawn mower will meet your requirements for cutting height, but if you like a particularly short or long lawn, it is worth looking at this feature closely to make sure that your chosen machine will meet your requirements.

Cutting Width

As a robot lawn mower moves across your lawn, the width of the strip of grass that will be cut depends on the width of the cutting blades. There is considerable variation in cutting width and it will impact how long it takes for your lawn to be cut. There are pros and cons of having a wider cutting mechanism in your robot lawn mower. Wider cutting mechanisms will get the job done quicker, but they are typically less power efficient and more noisy.

I look at this feature as a trade off between noise and working time. You can opt for a model that will produce more noise during operation, but that takes a shorter time to cut your lawn and spends more time in its docking station. This type of model is less likely to get in your way whenever you are trying to enjoy your garden. However, while it is working, it may impact the peace and quiet of your garden.

The alternative is to have a model with a narrow cutting mechanism that makes very little noise but spends more time cutting your lawn. You will typically see this type of model moving around your garden more frequently, but it will be less intrusive.

Personally, I would rather have a quieter robot lawn mower. I can schedule the robot lawn mower to cut my lawn while I am at work or at night so the time it takes to cut my lawn is irrelevant.

Models such as the Flymo 1200R and Husqvarna 105 have a cutting width at the lower end of the spectrum, at 17cm, but are also some of the quietest during operation. Compare this with the Robomow RS Royal 625 Pro, which has a massive 56cm cutting width, but is also one of the loudest models while working. 

Robot Lawnmower Battery Type

I think that it is important to opt for a robot lawn mower that uses a lithium ion battery for power. There are still a few models available that use old lead acid batteries. Lead acid batteries are cheaper than lithium ion batteries, but the advantages stop there.

Lead acid batteries have less power density, meaning that a lead acid battery of the same capacity as a lithium ion battery is much larger and heavier. They also last for fewer charge cycles and take a lot longer to charge than lithium ion batteries. A typical model using a lead acid battery will take 16-20 hours to charge versus about an hour for a lithium ion battery.

Another important point is that the capacity of a lead acid battery reduces faster over time than a lithium ion battery, and the degradation in charge capacity at higher temperatures is worse than lithium ion batteries.

Lithium-Ion batteries, have all of the advantages that lead acid batteries do not. They have higher energy density, longer life, faster charging and lighter weight. The cost of lithium ion batteries is decreasing slowly over time and the power density is increasing, leading to more affordable batteries with longer working time.

I think it is essential to pick a model that uses lithium ion battery technology, as the advantages far outweigh the higher cost.

Operational Time

The operational time of a robot lawn mower depends on a number of factors. Larger, heavier robot lawn mowers, with solid, individually rotating cutting blades, will have greater power requirements. Models can compensate for this by including a larger battery, but this will tend to increase the cost of the machine.

You cannot discuss operational time without mentioning the volume of grass that is cut per unit time. As mentioned previously, machines with larger blades and a wider cutting diameter will typically cut your lawn faster than those with a narrower cutting diameter. The main consideration is that the model that you are choosing will be able to maintain your grass in a well cut state and has a good balance of cutting rate, battery size and operational time.

You will also need to bear in mind that obstacles such as flower beds, ponds and garden furniture, as well as steep hills and long grass will increase the power consumption of your robot lawn mower. The operational time of a robot lawn mower can vary from as little as 45 minutes for the Robomow RC304u, up to 270 minutes for the Husqvarna 450X and 420 minutes for the Ambrogio L250i Elite S+.

Edge Cutting Ability

There are no robot lawn mowers currently available that will perfectly cut the edges of every lawn. If your lawn is bordered completely by a path or a patio, it is likely that most robot lawn mowers will be able to cut right up to the edge of your lawn and you will not have any maintenance of the edges to do. However, if there are sections of your lawn which are next to obstacles such as walls, fences, flower beds, or drops, it is unlikely that a robot lawn mower will not cut the edges perfectly.

There is some variation in the edge cutting ability of different robot lawn mowers, and this may be a factor in your purchasing decision. Typically, the best models for edge cutting are those from Worx and Robomow. Models for both these companies have more advanced edge cutting capability and can come pretty close to getting your edges fully cut. However, even the very best robot lawn mowers will still struggle to cut your grass right up to the edge of a fence or a wall. For this reason, if you are going to buy a robot lawn mower you do need to accept that you will need to maintain the edges of your lawn to some degree, or be content to have untidy edges.

I think the worst scenario would be to purchase a robot lawn mower without realising this limitation as it could lead to disappointment. If you are fully informed before making your purchase, I have no doubt that you will see the limitations in edge performance as a minor inconvenience rather than a deal breaker.

My own robot lawn mower cuts to the edge of my lawn perfectly where it meets my patio and path, and leaves a small strip of uncut grass of between 5 to 10 cm in diameter next to flower beds. I have to use an lawn strimmer around the edges approximately every 3 to 4 weeks to keep these looking neat. It only takes 10 to 15 minutes to do and is a minor inconvenience compared to having to do all the work myself with a traditional lawn mower.

Ability To Cut Longer Grass

Robot lawn mowers are designed to keep your grass looking freshly cut at all times. However, when you first get a robot lawn mower, your grass may not be freshly cut and might be quite long and unkempt. Similarly, after you bring your lawn mower out after winter maintenance, there may already be significant growth on your lawn. You should really get a robot lawn mower that will be able to manage longer grass so that you’re not left having to use a conventional lawn mower at any time.

Personally, I didn’t want my old conventional lawn mower cluttering up my garage, so I got rid of it. As a result, it would be a problem if my robot lawn mower could not manage long grass.

Thankfully, most robot lawn mowers will manage grass up to 10 to 15 cm in length. Some of them will take considerably longer to get through this grass than they normally would to maintain a well cut lawn.

As robot lawn mowers mulch the clippings, longer grass will result in significant clumping of the cuttings on top of the grass. After a few days of the robot lawn mower working, these clippings will be broken up and distributed into the lawn and should disappear from view. Alternatively, if they are particularly unsightly they could be raked up and disposed of.

Models from Robomow such as the RC Stylish and RS Royal ranges have a turbomow feature to allow them to cut through grass of any length. This increases the power and RPM of the blades and slows the robot lawn mower down, so that it slowly powers through any areas of long grass. I have found this to be an excellent feature, and have encountered no problems with any length of grass. If you are particularly concerned about the ability of a robot lawn mower to get through long grass, you should probably consider those with more heavy-duty cutting systems.  

Mulching

Robot lawn mowers do not collect the clippings from your lawn. This would be technically very challenging due to the need to dispose of the clippings when the collector was full. Instead, robot lawn mowers mulch the clippings, cutting them into very fine pieces and returning them to the grass. The clippings are sufficiently fine that they fall into the lawn, rather than sitting on top of it in piles. Grass clippings are more than 80% water, so they decrease in volume rapidly as they dry out. The clippings slowly break down and the nutrients within them are returned to the soil. This provides a source of nutrients for the growing grass, reducing the need to fertilise your lawn and leading to a healthier, greener lawn.

Before I owned a robot lawn mower, I used to fertilise my lawn approximately four times per year. This led to my lawn looking great, but only for 4-6 weeks, as I would remove the clippings after each cut, taking all the nutrients out of the soil. I now fertilise my lawn at the start of the growing season, and my mower cuts a little every day, returning all the nutrients to the soil, ensuring that my lawn stays green and healthy all the way through the growing season.

Cutting Technology And Blade Type

Robot lawn mowers usually have one of two types of cutting blade.

Models with a narrower cutting diameter tend to use low power cutting motors and blades compared to those models with a wider cutting diameter. Models from Husqvarna, Flymo, Gardena and Worx, for example, use a number of very tiny blades that are mounted onto a rotating disc. The blades are able to spin freely and have sufficient power to cut the grass but when they meet something more substantial they will retract backwards. This results in a robot lawn mower that will do less damage to any small objects that are left on your lawn.

robot lawn mower blades on rotating disc
Robot Lawn Mower With Small Cutting Blades Attached To A Rotating Disc

This type of cutting technology is designed to cleanly cut the blades of grass, minimising the stress to the individual plants, enabling them to recover as quickly as possible after they have been cut. As a result, this type of blade will need replaced every 2-3 months to keep them sharp and effective. The blades are normally very reasonably priced and buying in bulk online is usually the most cost effective option.

This type of cutting technology also has an advantage in terms of safety. If you were to come into contact with the blades of one of these models, the injury that you would sustain would be much less severe than if you came into contact with a model that used solid blades.

Secondly, there are mowers, such as those made by Robomow, which use one or two more substantial cutting blades, which look not dissimilar to the blades found on conventional lawnmowers. Due to their size and sturdier build construction, they typically need replaced less frequently, and are able to cut a wider strip of grass as the mower moves.

Robomow RC304u cutting blades
Large Individual Cutting Blades On Robomow Robot Lawn Mower

There are several negative aspects to this type of cutting blade. They use more power in operation and are typically louder than models that use smaller blades. They can also cause more damage to items inadvertently left on the grass.

For me, I much prefer a robot lawn mower that is as as quiet as possible, so I tend to prefer the models that use multiple cutting blades on a rotating disc. However, some manufacturers that produce models with more powerful, noiser cutting blades, such as Robomow and Ambrogio, produce really good robot lawn mowers, and sometimes the trade off is worth it.

Robot Lawn Mower Noise Level

Whichever robot lawn mower you choose, it will be considerably quieter than a conventional lawn mower. There are numerous factors that contribute to this.

Most people will be able to cut their lawn within 1 to 2 hours with a conventional lawn mower, depending on the size of the lawn. It doesn’t really matter if a conventional lawn mower is loud, because it is only an operation for a short period of time. However, due to the fact that robot lawn mowers are designed to keep your lawn in a freshly cut state all the time, and they work much slower than a conventional lawnmower, they will be an operation for much longer periods of time. For this reason, it is essential for a robot lawn mower to be as quiet as possible and cause minimal disturbance to the peace of your garden.  

If robot lawn mowers where as loud as conventional lawn mowers, and I had to endure the noise for hours at a time, I wouldn’t even consider buying a robot lawn mower.  Thankfully, most robot lawn mowers operate at between 58 and 65 dB in operation, with even the loudest models producing little more than 70 dB. My own robot lawn mower produces 58 dB in operation. Apparently, this is the same volume as two people holding a conversation. To be honest, whenever I am in the garden, I can barely hear my robot lawn mower when it is more than 10 to 15 feet away. Even when it is right next to me, it is really quiet and does not disturb the peace of the garden in anyway.

Other models that use more heavy-duty cutting mechanisms and have higher powered motors will produce a fair bit more noise than this. Robot lawn mowers from Robomow can produce noise of between 68 and 74 dB. According to a decibel equivalency chart that I looked at, this is approximately the same volume as a vacuum cleaner. While certainly much more noticeable, I would subjectively consider that a vacuum cleaner is a fair bit more noisy than the majority of the robomow robotic lawn mowers. This may have something to do with the fact that you use a vacuum cleaner inside and a robot lawn mower outside, which may change the characteristics of the sound produced. Either way, even the noisiest model on the market will only produce about one quarter of the subjective noise of a conventional lawn mower.

The key takeaway point here is that if you are someone who has a small garden or spend a lot of time in your garden, and wants to get a quiet robot lawn mower, I would strongly recommend that you choose a model that uses a multi blade system, and is rated at between 58-65 decibels. You won’t be disappointed.

Safety Features

Robot lawn mowers have been developed from the ground up with a range of comprehensive safety features. It would be very difficult to convince the general public that an autonomous robot with sharp spinning blades was a good idea unless they could prove that the safety features were comprehensive. Despite looking exhaustively for accident statistics and contacting a number of robot lawn mower manufacturers, I have been told by a number of sources that there are no confirmed reports of any injuries from a domestic robot lawn mower requiring treatment in an emergency department. This contrasts with conventional lawn mowers, which result in 80 000 emergency department attendances in the United States per year and 6000 emergency department attendances in the United Kingdom per year.

I honestly don’t know if the issue is the quality of the data that is being collected, or if there have actually been no accidents associated with robot lawn mowers. What I do know, however, is that robot lawn mowers are dramatically safer than conventional lawn mowers due to a number of factors.

Robot lawn mowers work autonomously. There is no need for a human to be anywhere near the blades of a robot lawn mower while it is in operation. Although not strictly a safety feature, this is undoubtedly a big reason why robot lawn mowers have such an exemplary safety record.

All robot lawn mowers are fitted with lift, tilt and obstruction sensors. If a robot lawnmower encounters an obstruction, it will stop, reverse, turn and move in a different direction. If a robot lawn mower encounters an obstruction that it gets stuck on, the robot lawn mower will stop functioning immediately. If anything causes the the wheels of the robot lawn mower to be lifted from the surface of the lawn or the machine to be tilted beyond a set angle, this will trigger the cutting blades to stop instantly.

This means that if a human or a pet comes into contact with a robot lawn mower, either intentionally or accidentally, the blades will stop turning before they are able to get close enough to the cutting blades to be at risk of an injury.

Another reassuring point is that robot lawn mowers use blades which are much smaller and have a lower power than conventional lawn mowers. For this reason, contact with the blades of a robot lawn mower is likely to lead to a much less severe injury.

Most robot lawn mowers have very little ground clearance. This means that an inquisitive child or pet would struggle to reach under a robot lawn mower in operation to come into contact with the cutting blades without first triggering the left or tilt sensors. It will not, however, protect small items that are left on your lawn. My father recently left a section of garden hose on his lawn and his robot lawn mower drove over the top of it, causing some damage to the hose, which required the section of hose to be replaced.

Despite the safety features of robot lawn mowers, it is still necessary to take precautions around children and pets. I  generally try to schedule my robot lawn mower to work at times that I know my children will not be using the garden, such as when they are at nursery or school, or in the evenings after they have gone to bed. However, if they are in the garden while the robot lawn mower is working, I am generally happy for it to continue working as long as I am constantly supervising them. if I am not able to continually supervise them in the garden, I am able to send the robot lawn mower back to its charging station with just a few button presses and can then restart the machine once my children have gone inside.

Collision Sensors

Robot lawn mowers move very slowly across your grass, so when they collide with a solid obstacle, there is no risk of damage to either the machine or the obstacle. Robot lawn mowers have a range of collision sensors to both detect and avoid obstacles.

Basic or more value orientated models rely on physical contact with obstacles to trigger them to change direction. Some robot lawn mowers use a floating shell chassis which physically moves when the machine encounters an obstacle. This triggers a Hall Effect sensor which detects the shell movement and is able to trigger the robot lawn mower to stop and move away.

Other sensors that are used to detect obstructions include accelerometers and wheel speed sensors. Both of these are able to detect sudden changes in movement speed, which will trigger the robot lawn mower to stop and move in a different direction.

More advanced models incorporate SONAR or LIDAR, to detect the proximity of the robot lawn mower to solid obstacles which might impede its progress. Some robot lawn mowers are able to change direction based on this information to avoid the obstacle in the first place.

As there is significant crossover between self driving cars and robot lawn mowers, I would be hopeful that some of the technology that is being developed for self-driving cars, such as visual obstacle detection, will be integrated into the future robot lawn mowers. this would lead to better avoidance of obstacles and more efficient navigation of your lawn.

Slope Ability

Robot lawn mowers have a number of adaptations which make them good for managing steep slopes. However, they are also built with power efficiency in mind, and a powerful motor which could manage a very steep slope, would be redundant for the vast majority of owners. Therefore, there is quite a range in slope ability between different robot lawn mower models, as manufacturers have targeted their mowers to different users.

At the low end of the spectrum, entry level models from Robomow such as the RX12U, can only manage a slope angle of up to 8.5 degrees, which is way below what other entry level models can handle. At the high end, the top performer is the Honda Miimo 3000 at a slope angle of 25 degrees. High end models tend to bunch together at a slope angle performance of between 20 to 24 degrees.

I think that slope performance is one of the more important things to consider before making a purchase of a robot lawn mower. It would be really disappointing to order a new machine only to discover that there was part of your lawn that it just couldn’t manage.

For people with relatively flat lawns you will have no issues, but for those people who do have significance slopes in their lawn, I would recommend doing a rough estimate of the slope angle or gradient before deciding what model to buy. The slope angle of your garden can be calculated very easily by measuring the rise and run of a section of the slope and calculating the slope angle or gradient from this. I have written a short article which explains exactly how to calculate this.

Cost Of Robot Lawn Mowers

Nobody likes spending more money than they have to on home appliances. I’m certainly a very cost conscious shopper, and am no different when looking to buy the best robot lawn mower for my money.

Robot lawn mowers have historically been quite expensive, but prices have been steadily falling over the last 20 years. This has been due to the maturation of the technology used, and the increase in the volume of units sold. With the market for robot lawn mowers forecast to grow by between 17 to 20% per year over the next 5 years, I think it is a safe bet to assume that prices will continue to fall for some time to come.

Entry level robot lawn mowers can be purchased for between £450 and £700, and models for larger gardens such as the Husqvarna 450X can cost up to £3,000. When you compare this to a conventional lawn mower, it can sometimes even work out cheaper to opt for a robot lawn mower. When you also consider the additional free time that you gain due to not having to maintain your lawn, this makes robot lawn mowers even more appealing. Robot lawn mowers also have fewer mechanical parts in comparison to conventional lawn mowers. This results in lower servicing and maintenance costs and it is important to factor this into your calculations.

I would certainly argue that the best robot lawn mower for most people will be one which meets their needs while providing value for money.

In my situation,  before I made the switch to a robot lawn mower, the conventional lawn mower that I used was a Hayter R53S. This currently retails for £600, and yet the first robot lawn mower that I owned was the Flymo 1200r, which now retails for less than £600 from a lot of retailers.

Some people have already dispensed with maintaining their own lawn and employ a gardener to do this for them. If I was to employ a gardener in my area to cut my grass, this would cost approximately £25. The growing season runs from April to September, so if I have my grass cut by a gardener on a weekly basis throughout the growing season this would cost me £575 per year to maintain my lawn. For people in this situation, the payback time for a robot lawn mower could be less than one year. You could buy the best robot lawn mower on the market and the payback time would still only be a few years. Of course, it’s not quite as simple as that, as there are other significant benefits of having a gardener, and it may be hard to give these up.

Multi Zone Capability

If your lawn area is divided into more than one section, you need to make sure that the robot lawn mower that you choose will be able to manage this. Most models will be able to manage a lawn that is split into two sections, but capabilities beyond this will vary from model to model.

There are multiple solutions to ensure that a robot lawn mower will be able to independently move between sections of lawn to cut them both. Even in scenarios where this is not physically possible, you will still be able to set up both sections of lawn for it to work on and manually transport the robot lawn mower between lawn sections as desired.

The best robot lawn mower solution may be to buy two! If you have two or more sections of lawn, is to treat them completely independently. Robot lawn mowers that can manage small lawns are very reasonable in price and will often be half-price or less compared to models that can manage double the lawn area.

It may be a better solution, and more economical, to get one robot lawn mower for each section of lawn. My father has employed this strategy extremely well and he has one robot lawn mower for his front garden and one robot lawn mower for his back garden. They both work completely autonomously, and this saves him from having to lift the robot lawn mower from the front lawn to the back lawn as required.

Settings Customisation

Regardless of which robot lawn mower you choose, you will be able to adjust the cutting schedule. You will be able to choose which days, and for how long each day the robotic lawn mower works. You will also be able to adjust the cutting height of the blades.

Some models have other features such as rain sensors, edge cutting mode or increased power modes. These can all be toggled off or on as desired. Basic models will enable adjustment of the settings on the physical keypad on the machine. More advanced models with integrated connectivity such as WI-Fi or Bluetooth, will enable you to adjust the settings via a smartphone or tablet app.

Smart Features

The best robot lawn mower doesn’t necessarily have to have any smart functionality. Smart features of robot lawn mowers are largely superfluous to the core functionality of the machine. They allow you to remotely connect to the robot lawn mower via bluetooth, WI-Fi, or GSM and either receive information or adjust the settings on your machine.

For robot lawn mowers that are suitable for small gardens, you will need to pay a significant premium to get smart features, and I would debate whether it is worth paying this. Once you get up to the mid-range and higher end models, smart features become more standard. It is certainly very handy to adjust the mowing schedule of your robot lawn mower from the comfort of your house, but it really isn’t usually necessary.

One feature that I enjoyed the most was the ability to manually drive the robot lawn mower via a smartphone app. I think Robomow do this particularly well and it is great fun to drive around your garden looking for patches of grass that need a little extra attention.

Robot Lawn Mower Security

Robot lawn mowers are fairly high ticket items and they spend most of the time in your garden. As a result, you would imagine that they would become a target for thieves. thankfully, the theft statistics of robot lawn mowers are very low. I think this is because the manufacturers of robot lawn mowers have focused on developing security measures which disincentivize criminals from targeting them.

Robot lawn mowers all come with a PIN code feature and alarm as standard. The PIN code is set in this control panel and the frequency that the machine will request the PIN code can be adjusted to suit your individual needs. One option is to set the machine so that the PIN code must be entered every time the machine is stopped. This would mean that any time the machine is lifted or the control panel is accessed, you must first enter the PIN code to do anything. This would include adjusting any of the settings, but also restarting the machine to return to work. This means that if a robot lawnmower is stolen, the criminal cannot use it without knowing the PIN code. You can also set the machine to ask for the PIN code only after a certain number of days if you live in a safer neighbourhood.

You can also set an optional or alarm, which can generally be set to go off if the PIN code is requested but is not inputted within a specific amount of time. The other option is to have the alarm go off whenever the robot lawn mower goes outside of the working area.

Some robot lawn mower models are uniquely paired to the charging base that they are supplied with. Therefore, even if a thief was able to steal your robot lawn mower and reset the PIN code, it would not work with a different charging base.

At the more expensive end of the market, robot lawn mowers often have additional connectivity, which will enable the machine to send you notification if the machine has moved outside of the working area, which may alert you to a theft.

For those models with GPS integration, you will be able to track the location of your robot lawn mower in real time. Therefore, if you receive notification that your robot lawn mower has moved outside of the working area, you can instantly know whether it has been stolen or whether it has just had an error. There have been a number of reports where an owner has reported a theft of a robot lawn mower, and been able to direct the police, via the GPS information to apprehend the criminal.

Although thieves may not be aware of the individual security features of robot lawn mowers,It does not take long for word of mouth to spread and for people to know that robot lawn mowers are not a good target for theft.This is likely to explain the fairly low theft statistics for robot lawn mowers.

Generally, robot lawn mowers are covered under your home insurance policy. Nevertheless, if you do make a robot lawn mower purchase, I would advise contacting your home insurance provider to let them know, so that you can be sure that it is covered in the event of a theft.

Robot Lawn Mower Environmental Credentials

Robot lawn mowers are a more environmentally friendly option than conventional petrol powered lawn mowers. Some of them can be amazingly power efficient. The first robot lawn mower that I owned used only 30 Watts of power during operation. Although it would cut my grass quite frequently, it would use as little as four kilowatt hours of electricity per month and cost less than £10 per year to run.

Obviously, it would be more environmentally friendly if I turned my lawn into a wildflower meadow, but in terms of an option to have a neat and well maintained lawn, I think that robot lawn mowers are one of the most environmentally friendly ways of doing this.

There is a fair bit of difference in the power use between different robot lawn mowers. Those with more powerful cutting blades and larger motors will use substantially more electricity than other models. If you are trying to minimise your environmental impact significantly this is an area to consider carefully.

Robot Lawn Mower Improvements I Want To See

Whilst I think that robot lawn mowers have now got to a point where they are a viable option for the majority of mainstream consumers, there are still a number of drawbacks and compromises which I would love to see improved over the next few years.

The biggest improvement that I want to see in future robot lawn mower models is a solution to the perimeter wire problem. Although the installation of a robot lawn mower only takes a few hours, perimeter wire installation will provide a massive barrier to a lot of people and limit the  rate of growth of the robot lawn mower market.

Advances in autonomous navigation are moving forward at breakneck speed due to advances in robotics, AI and computing. Self-driving cars and robotic automation present such a massive opportunity to business and society as a whole, that there is major investment in this field from a wide range of businesses, governments and organisations. Development by robot lawn mower companies, along with integration of generalised robotics, AI and computing advances will lead to robot lawn mowers without perimeter wire over the next few years.

It is interesting that the technology for navigating without perimeter wire already exists today. The only problem is that it requires a number of different technologies to make it work properly that are expensive and require considerable computational power. As a result of this, the cost of integrating it into a robot lawn mower is not currently economically viable, and it would lead to an increased risk of malfunction or failure of the device due to its increased complexity. These problems will be sorted in time as the technology matures, becomes more reliable and decreases in price.

The other major improvement that I want to see in future robot lawn mowers is the ability to cut edges properly. Great progress has been made over the last few years and there are now a number of models that get very close to perfectly cutting the edges of most lawns. However, for the majority of people, there is no current robot lawn mower that does not require any edge maintenance. This is another factor deterring some people from making the switch from a conventional lawn mower to a robot lawn mower.

I know that all of the major robot lawn mower manufacturers are working hard to develop ways to solve this problem, so I have confidence that edge cutting ability will continue to improve with each new model to the market.

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