Roborock S4 Max Review – A Reasonably-priced LiDAR Equipped Robot Vacuum

One of our favorite robot vacuums, Roborock's S4 Max holds the position of being the only vacuum-only robot in their product line-up. We found it's combination of ample suction and features to be a great combination.

Hands on Roborock S4 Max review

Roborock's S4 Max is among the highest performing vacuum-only robot equipped with laser navigation in it's price class. We're a fan of separate vacuuming and mopping robots, and the Roborock S4 Max is high on that list.

Real world use and testing

After reading many Roborock S4 and S4 Max reviews, we had to get our hands on one. When ours arrived, we immediately unboxed it, downloaded Roborock's companion app and setup our robot.

Setting up the robot for cleaning was simple. First, we seated the HEPA filter in the dustbin and placed them both in the unit. Next, using the included instructions, we paired the mobile App with our robot vacuum.

The last thing to do was to top off the battery. We chose a location for the dock that would keep it as out of view as possible while still being accessible.

While the robot was charging, we cleared any cords or other objects that wouldn't normally be laying around the house. Charging didn't take long as our robot arrived with 75% charge.

The progression of screenshots above show the S4 Max's progress mapping and cleaning for the first time via the App. The last screenshot shows named, individual rooms in the floor plan. Using the App, Alexa and Google Assistant you can simply ask for the robot to clean a specific room by name.

LiDAR mapping

Once the battery was fully charged, we told our S4 Max to start cleaning and it began to map the room it was in. As the vacuum's PreciSense LiDAR system scanned the room layout, a floor plan began to take shape within the App.

After a bit more exploring, the S4 Max had mapped the entire floor plan. We knew we wanted to use the room cleaning feature, so we did that next. On the same screen in the App, we then split the floor plan into several rooms. The App made it easy to define and name each room.

It's impressive to run this robot over and over again and experience trouble-free cleaning. The S4 Max has truly been a no-regrets purchase.

Within the App there are also two features that help keep the robot out of areas you want it to avoid. First, you can limit the S4 Max's cleaning area by creating a virtual wall (called an Invisible Wall in the App) on the floor plan. Invisible Walls are exactly what they sound like, and represented by a red line on the map. When the robot reaches an Invisible Wall it behaves as if it were a real one.

The second tool is a No-Go Zone. A No-Go Zone is a rectangle which is drawn on the floor plan in the App. A good use for a No-Go Zone would be to prevent the robot from cleaning beneath a desk with cords beneath it. There are a total of 10 No-Go Zones and Invisible Wall barriers available to customize where the S4 Max can and cannot go.

Cleaning and navigation

We instructed our robot to do a few random cleaning runs, first using Room cleaning. The S4 Max cleans by navigating along the edges of an area to be cleaned. It then vacuums the center of the area in neat parallel rows.

After owning robot vacuums by other manufacturers, we expected our Roborock unit to get stuck–especially on it's first run. But, everything went without a hitch.

The S4 Max did it's job, announced it was done, and returned to the dock to recharge.

Room cleaning and Zone cleaning

We also tried and really liked Zone cleaning. Zone cleaning allows you to draw one or multiple rectangular areas on the floor plan by dragging with a finger. Then, once instructed to, the S4 Max goes and cleans those exact areas.

The rooms we are cleaning have hardwood floors as well as carpeting in some room. Using the Zone feature we could draw just the high-traffic hallway areas to do a quick clean-up. We still use both Zone and Room cleaning months later (and we're still fans).

In all of our use, we've had only one instance where the robot truly got stuck and threw an error. This was over the period of more than 6 months of regular use.

Hardwood flooring and tile

Like most robot vacuums, the S4 Max performed at its best on hard flooring surfaces. We've found that even with its HEPA filter somewhat clogged it still does a near perfect cleaning.

The Scratchsafe floating main brush combines both bristles and flexible rubber fins. On hard floors, the bristles help vacuum up dust and other debris. When on rugs and carpets, the rubber fins agitate the carpet, loosening stubborn debris.

The robot has a single Side Brush that sweeps debris on it's right side in front of the vacuum. It's not perfect, but we're yet to find a perfect robot vacuum. All-in-all we found the S4 Max to be excellent on hard flooring. Fine dust, dirt and larger debris like cat litter and cereal posed no problem for the S4 Max.

Carpeting and Automatic Carpet Boost

The S4 Max has Automatic Carpet Boost which means that when it senses it is on carpeting, the level of suction is increased. Many robot vacuums have it, and it is a great feature.

As the robot encountered carpet, suction would increase (most notable by the increased sound the robot makes). As far as robot vacuums go, the S4 Max seems to be doing quite well with it's advertised 2000Pa of suction. It cleaned well on short and medium-pile carpet.

When vacuuming carpet, the main brush agitates the carpet. This make dust, dirt and debris more prone to getting sucked into the dust bin. It all works well, and the S4 Max scored well in our carpeting tests, too. As we'd expect with any robot vacuum, the highest pile carpet proves to be the biggest challenge. When on the surface of high pile carpet cereal, dirt, leaves and other debris are no problem. But, embedded deep in the carpet fibers, they can be tougher to clean.

Low-light (and no-light) cleaning

LiDAR-equipped robot vacuums are capable of cleaning in dim lighting, and sometimes even in complete darkness. We currently turn the S4 Max on (via the App) when we are upstairs for the evening. We found it to have no problem cleaning in complete darkness.

Suction, battery and charging

Vacuum Power modes and cycles offer different levels of cleaning

The S4 Max has 5 Vacuum Power Modes:

• Gentle - This suction mode is delivers the lowest amount of suction, creates the least amount of noise, and uses the least amount of battery power.
• Quiet - The quiet mode is the second lowest setting, delivering lower suction than the normal, or Balanced mode. It's also slightly quieter and uses less battery power than Balanced mode.
• Balanced - Balanced is the normal mode. It uses a medium amount of suction power at a median power consumption rate.
• Turbo - Turbo mode increases suction, ambient noise and battery consumption for a deeper vacuuming cycle.
• Max - As it's name eludes to, Max mode is the highest possible suction setting. While offering the highest level of cleaning, it also depletes the battery fastest and is the loudest of the suction modes.

Multiple cleaning passes can be achieved with the S4 Max's Cycle settings:

• 1x Cycle - The 1x cycle is the normal setting for the robot vacuum. When cleaning with this cycle, the robot performs a single-pass cleaning, navigating with a pattern of neat lines.
• 2x Cycle - When the 2x cycle is selected, the S4 Max cleans with two passes. The second pass makes neat lines at a 90 degree difference from the first pass creating a waffle or grid pattern.
• 3x Cycle - The 3x cycle adds a third pass, this time back to the same orientation use in the first cleaning run.

Using the Roborock S4 Max's App, Modes and Cycles can be combined to achieve any desirable level of cleaning. We initially only used the Balanced Vacuum Power mode with the 1x Cycle. But, as time went on we also used the 2x mode as well as Turbo Vacuum Power mode, both of which provided a much more thorough cleaning.

We used the 3x once just to test it (and to see the pattern it would create).

Battery management and recharging

After every cleaning cycle, the robot returns to its base to recharge. So, unless you are doing back-to-back runs, it is generally starting to clean with a 100% battery charge.

The size of the area combined with the power modes we used (1x and Balanced, or 2x and Balanced) never required a mid-cleaning recharge. To try to force a return-to-base and resume we run a triple-cleaning cycle at the Turbo mode.

The S4 Max did so well, finishing the test with plenty of battery to spare, we had to run it again, back-to-back. It worked as advertised. When the robot realized it was at risk of running out of power, it returned to its dock, recharged, then resumed cleaning.

Roborock S4 Max battery life test

We monitored the S4 Max's battery levels on that 3x cleaning cycle with the Turbo Vacuum Power setting. Almost all of the flooring surface was hard wood, so the Auto Carpet Boost was only activated periodically.

As you can see, we got excellent battery performance from the cleaning, even with a triple-pass and the higher Turbo power setting. We thought the vacuum would have to come in for a charge before completion, but at the 93 minute mark it had completed our test! The S4 Max had 45% battery remaining when it docked to recharge.

Even after a lengthy run on the second highest suction setting, the S4 Max had plenty of battery power left. While it might not have made the 180 minute max run time, this is very impressive as manufacturer max run times are based on ideal conditions and low power consumption modes.

We are planning to do a harder run on mixed or mainly carpet to see how the results compare when Auto Carpet Boost is heavily used.

Companion App, maintenance and usability

Android/iPhone App

We found Roborock's companion App for the S4 Max to work great. Everything from setting the robot vacuum up to defining and working with Room Cleaning and Zone Cleaning was easy to understand and worked as expected.

A few notable features the app includes are the ability to track the robot's cleaning progress in real-time, map management, scheduling and remote control.

Maintenance

The most active part of maintaining the S4 Max is emptying it's dustbin. Once you've done this a handful of times, you'll undoubtedly go look-up prices on robot vacuums with a self-emptying feature. It doesn't take long, but depending on the amount of dirt and debris your household creates, you may need to empty the dustbin every few cleaning runs.

You can see our S4 Max's filter after several vacuuming cycles. The full dustbin is in the background of this photo. We have simply tapped the filter against the side of the trash bin each time we empty it.

We also found ourselves wiping the robot down as the top of the S4 Max would get dusty from time to time.

Periodic maintenance tasks involves:

1. Emptying the dustbin and cleaning the E11 filter
2. Removing hair from the main brush roll, wheels and side brush
3. Cleaning the robot's sensors
4. Rinsing and replacing the E11 filter

The most frequent replacement, although we haven't had to replace ours yet, is likely the robot's Side Brush as it is always in contact with the floor or the floor and baseboard at the same time. The Main Brush roll is easily serviceable and replaceable. The washable E11 filter should last quite a long time, too.

Cost of ownership and replacement parts

The Roborock App provides a status of each of the three components, with an estimated lifespan in hours. From our use, it seems like replacements are likely measured in years, not months. Of course, the longevity of any robot vacuum's consumables depends on the home it is used in, which cleaning settings are used as well as frequency of use.

At the time of writing this, a pack of two Side Brushes cost $16.00, a Dust Bin Filter ran $33.00 and the S4 Max's Main Brush could be replaced for $23.00. These prices were taken from the manufacturer's website.

Overall, the cost of ownership seems in-line with other robot vacuums in this price and performance range.

Charging dock

The charging dock for the Roborock S4 Max is a charge-only dock. It's the size you'd expect and worked fine over 6 months of use.

Who should buy the Roborock S4 Max

• Anyone looking for a tried-and-true LiDAR-based robot vacuum at a great price should consider the S4 Max.
• If you live in a home with multiple floors, the S4 Max is a good fit as it can store up to four maps.
• Those owning larger homes will find the S4 Max a capable choice as it has very long battery life.
• Homes with complicated floorplans will find the S4 Max able to do a better job mapping and navigating than most competing robot vacuums.
• If reliability and longevity is important to you, the Roborock S4 Max is a great choice as it has consistently received very high customer reviews.

Who should avoid the Roborock S4 Max

• If having to empty the S4 Max dirtbin is a deal-breaker, you should consider Roborock's newer, more capable Roborock Q5+ as it can automatically empty itself.
• Since the S4 Max doesn't have a mopping feature, if you are looking for a robot mop and vacuum comibination consider one of Roborock's many mopping alternatives.
• Those seeking the latest robot vacuum technology available regardless of the price will be happier with a newer robot vacuum, such as the Roborock S7 MaxV Plus or Ultra.

Value for the money

With robot vacuums getting more and more expensive, Roborock has found a sweet-spot with the S4 Max. No, it doesnt have an auto-emptying bin. There are other robot vacuums with more suction on the market. It doesn't mop either, and we think that's a good thing.

The S4 Max is impressively equipped with LiDAR mapping and navigation, is multi-floor plan capable, has an intuitive app, and works very, very well.

MSRP was $429 for the S4 Max, but it is almost always available for far closer to $300. When we purchased ours we bought it from Roborock for $329.99. We have since seen it (again on Roborock's site) for $309.99. At any of those prices, including MSRP, it's a good value. If you can catch it for closer to what we paid, it's a steal!

Final thoughts

The Roborock S4 Max is a great robot vacuum and a no-regrets purchase. Of all the robotic vacuums we've tested, the S4 Max cleanly holds the position of reasonably-priced, highly performing vacuum-only cleaner. We recommend the S4 Max.