Robomow RS635 Pro SX Review: Is it Worth the Money?

In this Robomow RS635 review, we’re going to take a deep dive into Robomow’s flagship robot lawn mower to answer two simple questions…

Is it worth the £3,000 price tag?

And should you buy it?

The Quick Answer:

The Robomow RS635 Pro SX is one of the top robot lawn mowers I have used.

Yes, it’s expensive but it’s built to handle massive lawns that many people tackle with ride-on mowers.

But the bottom line is that it delivers an exceptional finish and the more it mows, the better the finish gets.

It’s a fantastic advert for the future of robotic mowing that could save you 3-5 hours a week.

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A Quick Overview of the Robomow RS635 Pro SX

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Let’s start this Robomow RS635 with a look at their promotional video. Then we can take a closer look:

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Key Features

Maximum Lawn Area: 5,000m; Run Time: 80 minutes; Charge Time: 110 minutes; Cutting Width: 56cm; Slopes: 36%; Weight: 20kg; Warranty: 3 years;

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Who is this Robomow Model For?

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Robomow has been building robotic lawn mowers for more than 20 years and the RS635 Pro SX is their flagship model.

It’s for those people with lawns up to 5,000sq meters. Although Robomow says it’s ideal for lawns of 3,600sq meters. For it to work well over 5,000sq meters, your lawn should be relatively flat.

Now, at around three grand, this model isn’t cheap. However, many people choose to tackle this size of lawn with a ride on mower. Lawns of this size are too big for electric mowers as the power cords aren’t long enough, cordless mowers don’t have the battery power and although petrol lawn mowers will do it, it’d take countless hours.

So the Robomow RS635 Pro SX is competing with ride on mowers.

You can buy a ride-on mower for the same kind of price and in many cases, they cost even more.

But the two main advantages this robot mower has over its ride-on cousins are;

1. It’s far cheaper to run. Around 34kWh per month which equates to around 3.5 litres petrol which a ride on can guzzle in no time. Plus, you can add £300-£500 per year to the cost of running a ride on in servicing fees.
2. It could save you 3-5 hours a week. Cutting the grass manually takes time, especially during the growing season when you might cut twice a week. The Robomow will do it for you and give you those hours back to spend as you wish.

So although £3,000 might seem a lot, you’ll probably save that in running costs over the years. Plus, it could save you as many as 80 hours between the months of April and September.

If you like the idea of saving both time and money, investing in a robot mower like the RS635 might make sense.

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Robomow RS635 Pro SX Design & Features

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I’ve broken this section down into three parts;

1. Mowing features
2. Mowing modes, and
3. Safety features

Mowing Features

The Robomow RS635 comes packed with all the features you’d expect from a top of the range model.

Mowing Modes

Different times of the year and different situations call for different settings.

The Robomow RS635 has a range of mowing modes to choose from so that no matter what conditions or circumstances it faces, it can mow your lawn to the highest standard.

Safety Features

Robomow machines have a number of safety features.

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Robomow RS635 Pro SX Performance

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So we’ve covered the features, but how does the Robomow actually perform in practice?

In a word…

Brilliantly!

The Set-Up

It’s fair to say that if you have large areas of lawn, the initial setup will take some time.

It took me a full afternoon.

If you have one large lawn with nothing in it to mark off, then set up is dead simple.

Still, laying the perimeter wire and setting this machine up for a lawn of 5,0000sq meters isn’t a quick job. This is especially true if you have trees and obstacles in the lawn that you want to mark off. You’ll use several hundred meters of perimeter wire which needs staking down every 1.5 meters or so.

That said, it’s a pretty simple process. Plus, they do have very useful videos on their site showing you how to do it.

Watch the video below to see how to do it;

However, if you have several areas of lawn that you want your robot to travel between, things start to get a little more complex.

It not overly complicated, you just need to pay close attention to the instructions.

Alternatively, Robomow offers an installation service where they send out a specialist installer who does the job for you.

It costs £299 but if you struggle to set it up on your own, it’s another option.

Everyday Operation

Over the course of 3 months, the Robomow worked relentlessly, coming out to mow for around 80 minutes before going back to recharge. Then once it’s recharged it came out again to carry on.

It took around 12 hours to fully mow the lawn I tested it on. At first, it did leave strips of uncut grass in areas that looked a bit untidy but as time went on, these were taken care of.

For best results, I set the mower up to work 6 days a week. It’s important to give it 24 hours off per week to re-balance the battery’s cells. Robomow says this is to ensure the batteries last as long as they should.

I chose to mow every day because I wanted to see how much it costs to run, which isn’t a lot. It used an average of 34kWh per month. At the time of writing, that’s less than a fiver.

I also wanted to see how mowing every day affected the health and appearance of the lawn.

Mowing every day does three things:

1. It stops the grass from growing upwards so it’s forced to grow sideways. This creates a denser, thicker and healthier lawn.
2. The cuttings get mulched into the tiniest pieces and consumed by the lawn almost immediately. This keeps nutrients and moisture in the lawn which keeps it healthy.
3. Your lawn will always have that ‘fresh cut look’. This isn’t possible when you only cut the grass once a week with a traditional lawn mower.

When used like this over the summer, you’ll notice the look and condition of your lawn improve significantly. And I’m glad to say that’s exactly what happened.

Like I said, the Robomow took a bit of time to ‘settle in’.

However, as time when on and the machine spent more and more time cutting the grass, the finish just got better and better. The constant mowing (combined with a good lawn care regime) encouraged new growth and the lawn got noticeably healthier and better looking, even within just a month.

It does all this very quietly too.

The birds don’t scatter like they do when I fire up a ride on lawn mower to cut this size of lawn. They just carry on about their business.

Maintenance

Keeping on top of maintenance is dead simple.

Every couple of weeks I just turned it upside down and brushed it down before giving it a wipe.

If you have lots of leaves and muddy areas, the tread on the wheels can get a bit clogged up. That said, it’s noting a stiff brush can’t easily handle.

Robomow recommends changing the blades every season. Because robot mowers cut the grass for hours on end, the edges will start to dull. How quickly this happens though, depends on how often you have the mower go to work and the type of grass your lawn is made up from. Course grasses will be harder on the blades.

Flaws But Not Deal Breakers

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I’ve really struggled to come up with something I don’t like about the Robomow RS635.

It’s such an impressive piece of garden machinery and during the 3 months I tested it, it didn’t miss a beat.

The only 2 things that might affect a purchasing decision are;

1. The cost – it’ll set you back three grand
2. It doesn’t leave stripes

And to be frank, those are hardly reasons to avoid it.

This machine is competing against ride on mowers, which, you could easily spend three grand on, plus running and maintenance costs.

And ride on’s don’t generally leave lawn stripes anyway.

 

Robomow RS635 Pro SX Review: Should You Buy it?

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If you have expansive areas of lawn and you like the idea of not having to mow it yourself, then the Robomow RS635 gets my top recommendation.

The three biggest reasons to invest are;

1. It’s comparable in price to a ride on mower but costs less to run and maintain. You could potentially save yourself £300-£500 in fuel and servicing costs.
2. Performance is just as good and in some cases, it’s even better than a ride on. It can handle even rough grass and works well on slopes where some ride on’s might struggle.
3. You’ll save potentially 3-5 hours a week because you won’t have to do the work yourself.

It’s also better for the environment, much quieter and it’ll leave your lawns looking much more manicured than a ride on mower ever will.

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