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

95.8/100

A winning track record of trouble-free cleaning on both carpet and hard wood flooring.

Published 1/03/2022

Roborock S4 Max Review

Verdict

Roborock's S4 Max is an excellent LiDAR-equipped robotic vacuum with support for virtual walls, multiple floor plans and easy scheduling.

We recommend the Roborock S4 Max 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 S4 Max is high on that list.

Pros and cons

What we like

  • Cleans well on both hard floors and carpets
  • Effective LiDAR mapping and navigation
  • Multi-floor capable (up to 4 maps)
  • No-go Zones and Virtual Walls
  • Automatic room recognition
  • Room, Zone and Scheduled cleaning
  • Automatic Carpet Boost
  • Easy set-up and use

What could be improved

  • Dust bin could be larger
  • Longer hair can tangle on main brush

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.

Progression of LiDAR Mapping Floor Plan

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.

Controlling the S4 Max with voice commands

Using the App, Alexa and Google Assistant you can simply ask for the robot to clean a specific room by name. Google lists the following commands the S4 Max can respond to:

  • Charge the vacuum
  • Dock the vacuum
  • Is the vacuum charging?
  • Is the vacuum running?
  • Pause the vacuum
  • Send the vacuum home
  • Start the vacuum
  • Start vacuuming
  • Stop the vacuum
  • Stop vacuuming

The Roborock Alexa Skill provides the same functionality although the commands are worded slightly differently.

Tip: Room and Zone cleaning with Google Assistant

You may notice that room and zone cleaning aren't listed in that set of commands. They do work with the S4 Max, however. If you name the rooms before adding the vacuum to Google Assistant, cleaning by room name does work.

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 laser 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.

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.

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 returns and vacuums the center of the area in neat 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.

Roborock S4 Max Bottom-side: Brushroll, Wheels, Side Brush

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).

Roborock S4 Max navigation

Before moving on, we wanted to note that the S4 Max doesn't seem to get stuck often. Flipping over the S4 Max, we analyzed the two powered wheels and front turning wheel. They are sturdy, and the robot does a good job climbing over uneven surfaces. The combination of power delivery and it's LiDAR navigation system are a winning one.

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.

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 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.

Carpeting and Auto Carpet Boost

The S4 Max has Auto 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.

Flooring SurfaceRoborock S4 Max
Tile & Hardwood99.3%
Low Pile Carpet95.7%
Mid/High Pile Carpet93.8%

One trouble area the S4 Max shares with other robot vacuums is vacuuming on mixed surfaces. When 1/2 of the robot is on higher carpeting, for instance, and the rest of the robot is on hard flooring, a void is created.

This void reduces the suction efficiency and is an area where all robot vacuums are challenged.

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.

S4 Max specs, features and what's included

Specs and features

  • Type: Robotic Vacuum
  • Mopping: No
  • Navigation: LiDAR
  • Cleaning pattern: Neat Rows
  • Dust bin: 15.6 oz.
  • Suction modes: 5
  • Maximum power: 2000pA
  • Max run time: 180 minutes
  • HEPA filter: Yes
  • Clean/Charge/Resume: Yes
  • Room Cleaning: Yes
  • Zone Cleaning: Yes
  • Virtual Walls: Yes
  • Multiple Map Capable: Yes, 4
  • Android/iPhone App: Yes
  • Alexa Compatible: Yes
  • Google Assistant Compatible: No
  • Home Kit Capable: No
  • Warranty: 1 Year

In the box

  • Roborock S4 Max Robot Vacuum
  • Dust Bin
  • HEPA Filter
  • Main Brush (installed)
  • Side Brush (installed)
  • Cleaning Tool
  • Charging dock/base
  • Power Cord
  • Owner's Guide/Manual

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.

Cleaning TimeBattery Life
30 min82% Remaining
60 min65% Remaining
90 min47% Remaining

Testing conditions: 95% hardwood flooring, Turbo Vacuum Power, 3x cleaning Cycles

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.

Cleaning our S4 Max's HEPA filter after several vacuuming cycles

You can see our HEPA 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 HEPA filter
  2. Removing hair from the main brush roll, wheels and side brush
  3. Cleaning the robot's sensors

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 HEPA 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.

Roborock S4 Max Dock tips

Tip 1: Some have stated that the robot struggled to find its dock. Be sure to place the Roborock S4's dock as specified in the user manual. We initially placed it far too close to chair than recommended.

Tip 2: If the robot finds the dock, but never successfully docks, clean the sensors on the bottom of the robot as well as the metal contacts on the charging base. Owners have stated that this alleviates any issues they experienced.

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.

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.