These days you can find affordable robotic lawn mowers that take the headache of lawn maintenance out of your hands. There are numerous models from various brands, some well known, others from obscure Chinese manufacturers. This is an in-depth look at the Kohstar s520 robotic mower. Is it worth your money? Find out in this short review.


Power rating: 85W
No. of Blades: 4
Blade Speed: 3000RPM
Cutting Width: 28cm
Cutting Height: 2.5-6cm
Slope Capacity: 30 degrees max
Battery: 6.6Ah Lithium
Charging time: 3 hours
Battery Life: 3 hours max
Max Range: 2600sq m
Sensors: Pressure, rain, Anti-theft, tilt, bump, touch, auto recharge
Controls: LCD Screen, Wireless Remote
Guidance Wires: yes, 600m max

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Here is a demo video of the product:

Main Features

The Kohstar s520 robotic mower is ideal for small to medium lawns and backyards. Its maximum working capacity is 2600 sq meters. This is a 4th gen mower from the company and a successor to their S510 model. And it has most of the advanced features you would expect from a current generation robotic mower.

Needs Border Wiring


And like any other robotic mower these days, the Kohstar also requires the installation of border wire. To guide the robot around your garden, you will have to lay them around the edges. This can be a time-consuming task, but it is just a one-time thing.

Functional Design

The actual design is pretty bog standard for robotic mowers. You get a glossy plastic shell, with large rear wheels for extra stability. The robot looks solid if unremarkable, and has waterproof exterior as well.

Blade System Kohstar 520

Decent Multi-Blade System

Let’s move on to the cutting mechanism. You get a four blade configuration under the hood with the. Those blades have a max cutting width of around 10 inches, which is pretty standard for this class. The cutting height is adjustable, between 2.5-6cm.

Acceptable Power Figures

Powering those blades is an 85 W rated electric motor. Thanks to this setup, the lawnmower has a decent max blade speed of around 3000RPM. You may not be able to cut very thick grass with this mower, but that is true with almost all other robotic mowers out there.

Battery, Charging, And Runtime

The s520 mower also has a standard auto recharge function. It comes with a docking station for charging the 6.6Ah lithium battery. Charging time is rather long at 3 hours, but you do get around 2-3 hours of running time on a single charge.

Charging Kohstar 520

On Ground Performance

And in that single charge, the robot can cut around 800 square meters of grass, more if it is plain ground. Many robot mowers struggle with uneven or sloped surfaces, but the s520 is an exception. It handles slopes up to 30 degrees with ease.

An Extensive Set of Advanced Features

Advanced digital features are the norm on any robot mower, and the Kohstar is no different. It comes with a remote, LCD, and a whole range of sensors including rain, touch, lift, and anti-theft. You can personalize settings like language, working times, passwords, and sub-areas in your yard.


  • Decent blade speed and cutting width
  • Comes with lots of advanced sensors
  • Silent operation due to smooth electric motor
  • Mostly automated functioning


  • Requires wire installation
  • Remote range is very low
  • Battery recharge takes a long time
  • No app feature

Important Notes

The mower will only function properly in temperatures under 40 degrees Celsius. And though you can divide your lawn into sub-zones using the wire, you can only make 3 zones. And the max wire length is only 600m, which can reduce the range of the mower further.


The Kohstar is a brand new mower armed with the latest features that you would expect from a flagship lawn mower. It is best for owners of smaller lawns and gardens under 2600 sqm. But the brand lacks market presence and is a Chinese product with limited localization. The product looks good on paper; these questions make it a risky proposition to be honest.

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