Robomow RS635 Review (Pro SX)

Lawn Mower Search Tool

Lawn Mower Search Tool


The Robomow RS635 Pro SX  is the largest sized model found in Robomows RS range and is the big brother of the RS625. It is recommended to work on gardens about 3600 m² in size (with a max of 5000 m²) making its closest competitors the Husqvarna 450x.

With features such as; the multi-zone function; the floating deck; the different mowing settings (modes); quick navigation; and mobile/tablet connection, you can expect it to put up a pretty good fight against its competition.

Throughout this review I’ll be analysing all of its features, functions and capabilities to help you understand if it’s the one for you.

Main Features

  • Rating: 8.5/10
  • Recommended Lawn Coverage = 3600 m² Max 5000 m²)
  • Mowing Time: 80-100 min
  • Multi-Zone Feature (4 sub zones, 2 separated zones)
  • Floating Deck
  • Mobile/Tablet Connection

Robomow RS635 Video

Have a watch of the video below to further introduce yourself to the Robomow RS635:

<< Check Price Now >>

Power System

Just like all Robomow models, the RS635 is powered by a 26V Lithium-ion battery and an electric motor. The difference with this flagship model from Robomow is the 26V 6Ah battery and features twin counter rotating 28cm tri-edged blades giving a wide 56cm cut.

As mentioned above, this provides enough power for the mower to cover areas reaching 3600 m² (with a max size of 5000 m²) and produces 80-100 minutes mowing before needed charged.

Because of Robomows efficiently engineered system the mower can work at a faster rate than most mowers so it may finish your lawn in one full sweep.

However if it doesn’t then you may have to wait up to 90 – 110 minutes for it to recharge. Which is quite a considerable amount of time you’ll be left with an unfinished lawn.


During the installation process you are required to peg down and house a docking station. This is what charges the RS635 and does so automatically.

Whenever out on a mow and needing charged, the robot will stop what it’s doing and head back to the station with the help from the perimeter wires. So you don’t need to charge it yourself after every mow.

Eco Friendly

As the mower is powered completely by electricity, it provokes no harm to the environment.

No emissions will be released into the air and because of its mulching function (more on that later) there will be no need for you to buy any nasty fertilisers.

This model is completely Eco-friendly so you’ll be doing Mother Nature a huge favour by swapping it with your old petrol mower.

It’s also very quiet so it won’t annoy the environment surrounding your garden – i.e. your neighbours.

Unlike the push mowers that can be heard from a mile away, the RS635 operates so quietly I doubt your neighbours will even notice when it’s on.

So you can program it to mow whenever you want, even during the night, and it still won’t disturb anyone.

<< Check Price Now >>

Model Comparison
Mowers John Deere Tango Honda Miimo Robomow RS635
Lawn Coverage 2200 m² 2000 m² 3600 m²
Noise Level 58 dB 75 dB 66db(A) in ECO mode | 74db High Load
Mowing Time 90 minutes 40 minutes 80-100 minutes
Charging Time 80 minutes 30 minutes 90 – 110 minutes
Dimensions 75.5×53.5x36cm 63.5x55x28.7 cm 73.5 x 66 x 31 cm
Weight 15 kg 11.6 kg 20 kg
Mobile App No No Yes
Rating 8/10 8/10 8.5/10

Mowing Features

Robomow 635 Pro SX BladesBlades

Underneath the RS635 you’ll find two big, 3 edged steel blades. They produce one of the biggest cuts in the market (at 56cm in width) which only speeds up its progress during the mow and can still cut the lawn very fine and accurately.

They are built to be much stronger and tougher than the little razor blades you find on the typical robomower. Meaning they are much longer lasting and will last the entire season without needing replaced.

Floating Deck

This feature is only found on Robomow models and no one else in the market, making it completely unique.

Not only that but it’s extremely practical and useful too.

Unlike most robomowers which blades stay still, the RS635 pro will move up and down with slope in the land. Keeping them completely parallel to your lawn, ensuring an even mow no matter where in your garden.

This is especially useful those with lots of bumps and holes in their garden. As no other robomowers can replicate this, the RS635 (or any other Robomow model) will be your best bet for getting to those hard to reach spaces.

Height Adjustment

Just like every other mower out there, you can adjust the height you want the RS635 to operate at. Cutting heights can be adjusted from 20mm to 80mm.

All you need to do is turn a dial in the control panel or, if you have connected your phone to the mower, you can adjust it through the app. It doesn’t matter which you choose, both are very easy to do and take no time at all.

You’ll probably find this most useful when you first get the mower and at the beginning of each season. This is when the grass gets longer than it should be so a larger cutting height is more suitable.

You don’t want to set it too low during these times otherwise you’ll take too much grass off and won’t make use of the mulching function.


Again another feature found within most robot lawn mowers.

The mulching function is actually one of strongest selling points for many robomowers in the market and it’s easy to see why. It has the power to transform your garden.

Because these mowers are designed to only cut little bits off your grass, the clippings are small enough to fit all the way down to the soil. Here they will decompose and act as a natural fertiliser (why you don’t need to buy any from the store).

The clippings then pass on nutrients to the soil to promote much better grass growth.

Resulting in a greener, thicker and healthier looking lawn.

<< Check Price Now >>

Narrow Paths

In order for this mower to work properly around your lawn, you need to ensure that there is at least 4-5m of space between one length of perimeter wire and another.

Just make sure you keep this in mind before purchase. If you have any areas of lawn which are narrower than this then the RS635 will not even be able to pass through here, nevermind mow it.

Robomow 635 Pro SX topMowing Modes

So that the RS635 can adapt to different environments and conditions, you have a selection of mowing methods to choose from.

Depending on the situation and time of year, you can change the RS635 settings so that it is better equipped to handle the task.

Turbo Mode

This tells the mower to work and spin its blades at a much quicker rate. But it can only be done for a short period of time because it uses up quite a bit of energy.

This mode is best suited to times where your grass has grown out a little too long, like in the beginning of spring. A very nice feature which, again, is not used by competitors.

Eco Mode

With this the RS635 uses minimal energy for cutting your grass and maintaining your garden. So when the energy bills get a little tight due to the time of year (autumn – winter), this feature is best suited.

However be warned this does slow down the RS635 work rate so will take longer to finish the mow.

Edge Mode

This program instructs the RS635 to follow the perimeter wire and cut the borders of your garden.

The Robomow mowers are only part of a small group models that can actually reach and cut the outer limits of your garden. So they have come the closest to completely removing you from garden work.

However the problem is still not quite solved yet. If your garden is next to the wall of your house, the RS635 still can’t cut the grass along it. So will, after every mow, have to go out with the trimmers and clean this up.

Even though this can be quite annoying, this will be a much easier task than you’ll have after another mower.

All of the above modes will automatically turn off and reset to regular cutting after one complete cycle.

Rain Sensor

To protect itself and your garden from any damage, the RS635 has built-in sensors to detect when it starts raining. So at any time when your mower is working away and droplets begin to fall, it will automatically make its way back to the docking station.

And if it hasn’t even left the station, it will just stay put until the rain stops or until the next mowing session has begun.

You can also alter how sensitive you want it to be to the rain. So when it’s just spitting, you can set the mower to just keep mowing.

Robomow AppRobomow App

As stated before, you can connect your phone or tablet to this mower using the Robomow app. So if you have an overly busy lifestyle then you’ll just love this feature.

You can monitor its progress, you can receive message alerts and change its settings just as if you were there in person. A truly brilliant feature that makes your life that little bit easier.

And if you do manage to find that extra bit of time, maybe at the weekend, you can control it just like a toy car.

So if the RS635 struggling with a particular part of the garden, or if you just want to revert to your ten year old self, you’ll find this really cool.

It’s also worth mentioning that the base station will need to be in range of your WIFI  signal in order to use the app.

<< Check Price Now >>



To combat the more complex of gardens, the RS635 can travel between 7 separate lawn areas provided they are connected by passage ways.

You just need to make sure you have followed the installation process properly and you’re good to go. The RS635 comes with more robust wheels so it can drive over surfaces that are tougher than grass, i.e. your driveway and paths.

So instead of having to carry it from one area to the other or dragging out the ole’ petrol mower, you can let the mower roam free.

Also, you’ll need to make sure the size of all areas combined is under the RS635s mowing limit (5,000m²). Otherwise it will be out of range and therefore can’t cover all zones.

Robomow do offer an installation service that costs around £300 and is well worth it as it can take many hours to get this install working perfectly.

Safety Features

To keep you and your friends/family safe while the RS635 is at work, it has a number of safety features installed.

PIN & Alarm System

This ensures that anyone without a code will not be able to access and operate the mower. And if they try, you will be notified immediately by the alarm and by a notification on your phone.

This should scare off any burglars that fancy a look at your mower and will let you sleep a little softer knowing its safe and sound outside (well unless it actually goes off, then I’d imagine you’d wake up).

To turn off the alarm, all you need to do is open up the control panel and key in the PIN code.

Bump Sensor

If at any point while on a mow the RS635 comes across an obstacle, its bump sensors will prevent it from any damage.

Once activated, the mower will stop in its tracks and the blades will stop rotating. It will then recalculate and follow a new route.

And just to be extra safe, the RS635 comes with a big, red stop button beside the control panel.

Lift & Tilt Sensors

To prevent any injury to user, the RS635 has sensors which automatically turn off its blade whenever it’s lifted or tilted. So when you need to change the blades, know you’ll be completely safe.

But still be careful, you are still dealing with sharp blades.

Another thing, when you are lifting the mower lift it from the back. As you know this mowers blades are quite large so they’re closer to the mowers edges than most.

I might be being a little too cautious but better safe than sorry!

<< Check Price Now >>


So that you’re aware of everything that comes with this mower, it’s important that I tell you about some of its flaws. I have nothing to hide, I just want you to find the perfect mower.

But don’t worry these problems will be minor at most and shouldn’t take too much effort to handle them.

  1. The mower can’t travel over ledges. This is probably obvious, but if the mower were to drive over a ledge, it will get thrown off course and/or break.
  2. Even with the edge mode the mower still leaves a little bit of work for you to do, mainly around fences and walls. So you’ll need to do some trimming every so often.
  3. If your garden is separated into different areas and they aren’t linked then you’ll have to carry the mower about. This might be an annoying task but it’s certainly a lot less annoying than carrying a full size, push mower to do the same thing!

Hopefully these aren’t too much to ask for. If you consider everything else you get I think it’s more than reasonable to accept a couple of flaws.


Even with the downsides discussed above I am still impressed with the Robomow RS635, and I DO think it’s better than its competitors.

It has all the necessary mowing features – a reliable blade and cutting system, efficient navigation and adequate safety features – needed for an effective robot mower. The mower produces an excellent lawn finish, needs very little maintenance and is very quiet in operation (Guaranteed to be less than 74 dB).

This is not the cheapest robotic mower but once you have one, the running costs are very low compared to say a petrol mower for example.

Plus all the extras that separate it from the rest, like the Robomow app, the floating deck and the rain sensor.

With all of these considered, there is something that puts the RS635 (or any other Robomow model) ahead of the rest… and that’s VALUE.

This is quite possibly the most important aspect you’ll be looking for in any robomower, they are expensive and you’ll be expecting a quite a lot in return for it.

With the RS635 you get so many features that the price is completely justified.

So if your garden suits I know you’ll love this mower, in fact I think you’ll regret not getting one sooner!


To help you decide if this mower’s for you, I’ve laid out some categories below. They describe the RS635s “perfect” customer so they should help you understand if you both are compatible.

  • Their garden is between 3,600m² and 5,000m² in size.
  • Their garden is sloped and bumpy
  • Their garden has a complex shape
  • Their garden is separated into more than one lawn area (up to 7)
  • They don’t have time to maintain their lawn properly
  • They make full use of the mobile app
  • They don’t mind doing some trimming now and then

Hopefully I’ve made this process at least a little easier than it was before but if not just drop a comment below. I want to help you out as much as I can so feel free to answer me anything.

Where Can I Purchase This Model?

Cheltenham Mowers Ltd (Lawnmowers UK) is a family-run business with many years of experience of selling, servicing, and repairing lawnmowers, mowers, garden tractors, lawn tractors, brush cutters, hedge trimmers, chainsaws, garden vacuums, garden shredders and all other types of garden machinery – whether for domestic or professional use.

<< Check Price Now >>


Additional Specifications
Recommended Working Area 3600 m²
Maximum Working Area 5000m²
Max Incline 20° or 36%
Battery Type Lithium-Ion 6Ah
Battery Power 26V
Power Consumption 34 kWh/month
Mowing Power 400W
Typical Charging Time 90 – 110 minutes
Typical Mowing Time 80-100 min
Snap On Blades Yes
Cutting Height (min-max) 20-80 mm
Cutting Width 56 cm
Sound Level ECO Mode: 66 dB High Power: 72 dB Measured (Guaranteed – 74 dB)
No. Of Zones 7
External Base Setup Yes
Alarm Yes
PIN Code Yes
Rain Sensor Yes
Floating Deck  Yes
Lift Sensor Yes
Tilt Sensor Yes
Perimeter Wire 100m or 200m
Product Size LxWxH 73.5 x 66 x 31 cm
Weight 20.0 kg


Review Date
Reviewed Item
Robomow RS635 Pro SX
Author Rating
Product Name
Robomow RS635
Please Share!

Leave a Reply

Your email address will not be published. Required fields are marked *