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Kyvol Cybovac S31 robot vacuum review: Quiet 2-in-1 cleaning and a long battery life

Written by Eileen Brown, Contributor
Kyvol Cybovac S31 robot vacuum review ultra-powerful quiet two-in-one cleaning and long battery life zdnet

Kyvol Cybovac S31

8.4 / 5

pros and cons

  • 3000Pa suction
  • Quiet in use
  • Auto-empty station
  • App configuration issues
  • Ultra bright docking station light

The Kyvol S31 robot vacuum is the latest in line of robot vacuums that automatically empties the robot's onboard dustbin, a boon for people like me who find the daily emptying of the robot's dustbin a bit of a drag.

Its charging base has an integrated charging base with a 4.3L self-emptying dustbin. So when the robot gets back to its base, the dust is extracted into the charging base.

The robot itself is powerful with a 3000Pa suction motor, which is the most powerful motor I have ever tried. It is quiet, too, at approximately 45 decibels so is hardly noticeable in use.

The S31 uses Laser Distance Sensors (LDS) to navigate and store the map of the area. It has a long runtime of up to four hours from its 5,200mAh battery -- but I found that it never ran out of battery no matter how much it cleaned the area.

If the battery does get low, the Kyvol S31 will go back to its charging base and recharge, before going back to the last spot it cleaned and finishing the job.

Like many robot vacuums, through the app, you can select cleaning zones, and apply a cleaning schedule. The app was easy to install and connect to the S31 – but I had significant challenges after I installed the app.

The app decided that the firmware of the S31 needed to be updated. It would not update the firmware until the battery was charged to more than 20%. The robot showed a pulsing white light -- indicating it was fully charged -- yet I could not update the firmware.

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I kept the robot on its charger for three days and checked several times that the charge points were not covered in plastic film, and the on-board battery was working. I could not get past the firmware update on the app.

I gave up and decided to use the robot manually by using the supplied remote control unit. Strangely, after the first sweep initiated by the remote control, the firmware updated and I could adjust the settings in the app as normal.

Since then, the app has given me no issues at all. The app is adequate -- but not as sophisticated as the Roborock or Ecovacs apps. It seems a little pixelated compared to others. However, it has similar settings to configure and does not seem to lack features.

You can also control the robot by voice, but I prefer the 'set it and forget it' approach using the schedule to clean the floor each day. I often forget to use voice-activated devices, and I do not want to be around when the robot is doing its bit.

When the robot has finished its clean it goes back to its dock and swivels around so it effectively reverses into its parking slot. The motor on the auto-emptying station sucks the dirt out of its onboard dustbin. The robot then swivels around again to charge itself.

Like many other robot vacuums, the S31 can sweep and mop floors at the same time. The mopping cloth wipes the floor as the robot moves forward. It does not scrub the floor like the Deebot mopping accessory or the vibrating mop of the Hobot Legee 688.

It is fine for everyday mopping, but if your floors get really dirty, I would recommend that you scrubbed the floors first and then set the robot for daily mopping. The only challenge is that when the mopping module is on the robot, then the robot will not auto-empty itself.

The mopping module tank is only 110ml, so if you have a large expanse of hard flooring, you will need to fill up the module more often. I pre-wet the mopping cloth to make sure that the cloth starts to mop immediately and there are no dry areas until the mop cloth becomes damp.

Like the Neabot, the light on the charging station is incredibly bright and lights up the room in the middle of the night. This might be an issue if you keep the Kyvol S31 in your bedroom. You might need to mask the light to get a truly dark room if you do not need a nightlight.

However, these are small issues, and now I understand how to get access to the app, for under $250 the Kyvol Cybovac S31 is a joy to use.

It has been a pleasure trying this efficient, powerful robot -- perfect for anyone who hates emptying the vacuum's dustbin.