The Content Of The Article:

Lost in sight for two years, wireless lawn mowers are back in force thanks to lithium-ion battery technology. A striking test.

Bosch Rotak 43 LI cordless lawn mower


Maker: Bosch
Reference: Rotak 43 LI
Weight: 15 kg
Voltage: 36 V
Cutting width: 43 cm
Cutting height: 9 positions from 35 to 70 mm, centralized adjustment
Capacity of the tray: 50 liters
Front wheels: Ø 145, width 45 mm
Rear wheels: Ø 170, width 60 mm
Mancheron: adjustable 2 positions
Sound level: 84 dB (A)
Guarantee: 2 years
Price generally found: "Rotak 43 LI" 599 Euros

Functions and accessories

A battery at the top
At equal voltage, the lithium-ion battery is distinguished from a cadmium-nickel (NiCd) battery by a smaller size. It keeps all its power during operation: when it is "empty", the machine simply stops. Another advantage, it retains the charge, even if it does not serve for a month, unlike the NiCd, subject to a memory effect that decreases its performance.

The battery of the machine informs on its level of charge by three indicator lights. Even partially empty, it recharges without loss of performance. Flat, it fills completely in 1 hour. But after thirty minutes of charge, she found 80% of her abilities.

The charger is ventilated to cool the battery before and during charging if necessary. Indicator lights give the necessary indications (level of filling, battery too hot or defective, etc.).

With L-I batteries providing 50% more power, 40% less weight than NiCd and lead, the mower can be equipped with powerful, compact and lightweight 36V batteries.

When using
A few seconds are enough to mount the handlebars, adjust its height (2 positions), place the grass catcher and insert the battery. The mower is ready to start by pressing the dual control.

A load makes it possible to mow a lawn of about 150 m2 with a height of 5 cm. Start-ups and repeated stops to empty the tank reduce its autonomy. But the machine comes with a second battery. While one is working, the other can recharge. Thus, 300 m2 are cut in about 1 hour 30 minutes.

Weighing only 15 kg empty, the mower is used without much effort on flat ground. The cut is excellent on a dry grass and not too high (less than 10 cm). Beyond that, the battery runs out quickly. It is then necessary to advance more slowly and to stop as soon as the tank is full. Rather summary, it fills up well if you progress at moderate speed.

Side noise, small disappointment: 84 dB (A) measured at the end of the handlebars, the equivalent of the models to wire.


  • The lithium-ion battery is undoubtedly what we do best today. Its performance, its lightness and its compactness make the device efficient and manageable to circulate between the massifs and around the trees.
  • Its price is very competitive compared to the sector devices with the same cutting width.
  • The second battery provided is a real advantage, multiplying the autonomy to infinity.

The lessers

Despite its aerodynamic look, the mower disappoints mainly by its very "plastic" general design (cutting height control, bodywork, wheels). This reserve can explain its price...

Our opinion

Recommended by the manufacturer for gardens up to 600 m2 (there is a 37 cm model for lawn 300 m2 (Rotak 37 LI, 190 Euro), this lawnmower offers all the advantages of wireless at a reasonable cost. however, do not damage the plastic parts.

Check the battery

Check the battery

The charger has indicator lights giving many parameters on the status of the battery.

Set up or remove the battery

Set up or remove the battery

The protective cover must be raised to place or remove the battery.



Safety side, a "key" can block the operation of the mower if the battery is left in place.

Video Instruction: Bosch ROTAK 43 Li ErgoFlex Cordless Lawn Mower - FIRST LOOK