Hobot 2S Ultrasonic: A robotic window cleaner with a dual-fluid delivery system

Hello to all readers! This review will examine the new HOBOT-2S Ultrasonic window cleaning robot. This flagship model, available at the end of 2021, features two tanks with ultrasonic cleaning fluid sprayers. This allows the robot to automatically wet the cleaning surface as it sweeps across the glass in both directions, improving window cleaning efficiency. Additionally, the device boasts updated vacuum sensors for navigation and safe operation, as well as new cleaning cloths that better remove dirt from corners. Another important upgrade: the Hobot-2S announces its status in Russian during operation, keeping you always in control. You can also record your own messages. Replace the default messages with custom ones, using your preferred voice. Below, I'll take a detailed look at and test the HOBOT-2S Ultrasonic, after which I'll share my opinion on whether this window cleaning robot is worth buying. Incidentally, its price at the time of writing is $350, placing it in the premium segment. So, let's get started!

Equipment

First, let's take a look at the HOBOT-2S Ultrasonic package contents. Besides the robot itself, the box contains:

1. Set of 3 cleaning wipes.
2. Power unit.
3. Cord for connecting the power supply to the network.
4. Extension.
5. Documentation for the robot with translation into Russian.
6. A bottle of branded cleaning liquid.
7. Sprayer for bottle.
8. Spare ultrasonic nozzle.
9. Remote control with power supply elements.

The kit is well-equipped. It includes all the necessary accessories and spare parts for operating the robot.

Appearance

Now let's take a look at the HOBOT-2S Ultrasonic's design. It's square and comes in a black and white color scheme. Its dimensions are 240 x 240 mm, while its height is only 86 mm, making it suitable for use on windows with bars.

On the top of the body, you'll find a threaded power connector, an on/off button, and a start/pause button. The sides are recessed for comfortable gripping.

On both sides are tanks with ultrasonic sprayers. Each tank holds 26 ml of cleaning fluid. A safety cable is immediately attached to the robot and can withstand a load of up to 200 kg.

Let's take a look at the underside of the window cleaning robot. It moves on two tracks with rubberized treads. Anti-fall sensors are installed at the corners, and through-holes are provided in the cleaning cloth for these sensors.

It turns out that the sensors are installed not in the very corners, but closer to the center. This allowed us to increase the surface area of ​​the wiper, allowing it to better reach the corners. However, we still see that the corner is not completely covered by the wiper. There are plastic protrusions in the corners—limiters—that the wiper must be centered on. These protrusions allow us to clearly determine the window's boundaries when it hits the rubber seal.

Let's return to the sensors; they control the robot's attraction to the window. Instead of the usual mechanical and optical sensors, the robot is equipped with vacuum sensors, which are more sensitive. The main motor's ventilation holes are located in the center, allowing the window cleaning robot to adhere to vertical surfaces.

Overall, there are no complaints about the build quality of the HOBOT-2S Ultrasonic. The plastic is high-quality, the body is ergonomic, and every component is well-designed.

Technical specifications

The main characteristics of the HOBOT-2S Ultrasonic, as stated by the manufacturer:

• Battery: Li-Ion, 650 mAh.
• Power consumption: 72 W.
• UPS battery life: 20 min.
• Minimum window size: 40*40 cm.
• Maximum window size: 500*600 cm.
• Dimensions: 240*240*86 mm.
• Weight 1.3 kg.
• Noise level: 62 dB.
• Travel speed: 2.4 min/1 sq.m.

Overall, the characteristics are quite standard for a robot window cleaner.

Functional capabilities

Let's move on to an overview of the HOBOT-2S Ultrasonic's features. This robot can be controlled both via a remote control and a proprietary mobile app. Let's first explore the app's capabilities.

Connecting to a Wi-Fi network is easy. Scan the QR code in the instructions, download the app, and connect the robot following the manufacturer's instructions.

The main working panel contains the following functions:

• Automatic car wash with Z-shaped serpentine from the left edge.
• Automatic car wash with Z-shaped serpentine from the right edge.
• Automatic wash with Z-shaped serpentine from the top edge and a second pass with N-shaped serpentine.
• Manual control of the robot using the corresponding buttons.
• One-time spraying of liquid in manual mode.
• Starting the automatic mode with a double pass of the available area.
• Turn liquid spray on/off.
• Stopping the window washing process.

In the "Help" section, you can find useful information about using the window cleaning robot, and in the settings section, you can update the firmware if necessary, change the robot's name, select the language and volume of voice alerts, and even re-record your own voice commands. As mentioned earlier, the HOBOT-2S Ultrasonic speaks Russian.

The smartphone app also tracks the window cleaning process, sends reminders for window cleaning, and updates the app. The app itself is updated very conveniently, over-the-air (OTA) via the app's over-the-air (OTA) system.

As for remote control, it duplicates all the same functions as the app's main panel. So you can choose the control option that best suits your needs.

In general, the robot's functionality is complete, let's move on.

Testing

A detailed video review with all the tests has already been prepared and published on the channel. I recommend watching the video:

Navigating large and small windows

Let's move on to the tests. First, let's check how well the HOBOT-2S Ultrasonic navigates. It cleaned the large window without any problems, leaving no unexplored areas.

However, on a narrow window, just 35 cm wide, it can move, but it can't fit flush against the window frame, only touching one side at an angle. Therefore, the minimum window size for effective operation should be 40 cm, as stated by the manufacturer.

But there's a way to use this robot to clean narrower windows, too. This involves vertical installation! In this mode, the robot will move vertically, rather than horizontally, along the window.

Window cleaning quality

Now let's test how well the HOBOT-2S cleans the outside of the window. Before starting the cleaning, I sprayed a small amount of cleaning fluid onto the cleaning cloth in the appropriate spots, as recommended by the manufacturer, and then filled the reservoirs with the proprietary cleaning fluid. This allows the sprayers to clean larger glass surfaces more effectively, preventing the cleaning cloths from drying out by the end of the wash.

The window was cleaned quite well. The HOBOT-2S didn't remove some heavily dried dirt. Therefore, please note: don't use the HOBOT-2S Ultrasonic in windy conditions, as I did. Strong gusts of wind will prevent the liquid sprayed from the ultrasonic nozzles from fully reaching the glass; it will simply be blown away. This will reduce the effectiveness of the automatic spray.

But if you run the robot in calm weather, the liquid will reach the glass as intended. The advantage of ultrasonic spraying is that the cleaning fluid pre-dissolves the dirt, preventing streaks and runs. Furthermore, the sprayer allows for more thorough cleaning of large glass surfaces, as the wipes don't dry out by the end of the wash.

The only thing is that the cloth still doesn't quite reach the corners, but the remaining unreachable area is smaller than most other robotic window cleaners, which have sensors located right in the corner.

Here's the cloth after washing the window. As you can see, it's collected dirt and dust:

Other features

I'll also explain how the HOBOT-2S Ultrasonic operates in emergency mode. When the power goes out, the robot emits voice alerts and the indicator on the control panel starts flashing red, while push notifications are sent to the connected smartphone. You'll have about 20 minutes to react promptly and remove the robot from the window. Remember to secure the safety tether to a stationary object to prevent the robot from falling from a height.

It's also worth noting that the device is suitable for cleaning not only glass but also other hard vertical surfaces with a soft texture. For example, it can be used to clean tiled walls in a bathroom. Incidentally, it's worth noting that the HOBOT-2S Ultrasonic is also suitable for cleaning frameless windows. When it detects a break, it retracts, preventing it from falling from a height.

Keep that in mind, though, as the robot can't work on horizontal surfaces. Although, to be honest, I don't see much point in this feature.

Let's sum it up

The HOBOT-2S Ultrasonic was thoroughly reviewed and tested. I'll share my opinion on this window cleaning robot after trying it out. I liked the following:

1. Control via remote control, mobile app and button on the body.
2. Good navigation, including taking into account the new type of vacuum sensors.
3. Suitable for washing frameless windows.
4. Double module for automatic surface wetting.
5. The cloth covers more of the non-washable area in the corners.
6. Good equipment.
7. Russified voice messages, as well as the ability to record your own creative messages.
8. The compact size of the body allows it to be used even on windows with bars.
9. High build quality.
10. 3 years warranty from the manufacturer.

As for the shortcomings, the following were found:

1. In windy weather, the cleaning fluid delivery system is less effective, as some of the steam is blown away by gusts of wind. In this case, simply moisten the cloth again before washing, especially since the manufacturer recommends moistening it before the main cleaning.
2. A small area in the corners remains unwashed.
3. The washer is not capable of functioning on horizontal surfaces.

The comments aren't particularly critical, in my opinion. My main complaint is about the ultrasonic spray. This technology has its own nuances, which are justified by the increased effectiveness of window cleaning. In any case, the HOBOT-2S Ultrasonic has left a largely positive impression and deserves attention, as well as being considered one of the best. The best window cleaning robots at the end of 2021.

I'd like to end this review on that note. If you have any questions, please ask them in the comments. Happy shopping, everyone. Bye!