Kärcher RLM 4

Product description

The robotic lawn mower Kärcher RLM 4 is suitable for an area of approximately 500 m2 according to the manufacturer’s recommendations. The area size takes into account the mower’s design parameters. The working area is defined by the boundary wire. The mowing method and the mowing movement is random. Continuous information about already mown area is not available. Robotic lawn mower returns to the charging station along the wire. The cutting width is 20 cm. The range for cutting height adjustment is from 25 mm to 55 mm. The robotic lawn mower Kärcher RLM 4 can mow the area of the maximum slope of 24 degrees or 45 percent. The motor of Kärcher RLM 4 is designed brushless. The battery capacity is 2.5 Ah, which represents the overall energy of 45 Wh by the system voltage 18 V. The charging time is approximately 45 minutes. The robotic lawn mower with the full charged battery can mow for 50 minutes. The mower weight with the battery included is 8.8 kg. For technical information about Kärcher RLM 4 features and other parameters, see Technical specifications or visit manufacturer’s website.

Technical specifications

Product: Kärcher RLM 4

Area Size Up to
(specified by the manufacturer):
500 m2

Cutting Width: 20 cm

Cutting Heights Range: 25-55 mm

Blade speed: 3200-3400 rpm

Maximum slope (degrees): 24°

Maximum slope (percent): 45%

Motor Type: brushless


Battery Capacity: 2.5 Ah

System Voltage: 18 V

Number Of Batteries: 1.0

Battery Total Energy: 45 Wh

Charging Time: 45 min.

Maximum working time: 50 min.


Product Length: 598 mm

Product Width: 400 mm

Product Height: 285 mm

Weight incl. Battery: 8.8 kg

Guaranteed sound power level: 60 dB(A)

ver. 1902


For easy detection of the slope degree, we recommend using a digital spirit-level when selecting a robotic lawn mower. It allows you to measure the slope in degrees. To make sure that you correctly identify the maximum slope value on your lawn, it is necessary to measure it at multiple locations and take into account the highest value measured.