Honda HRM300/500 Owner's Manual page 53

Cleaning the docking station
N WARNING
- Unplug the transformer's plug from the power outlet (House) before cleaning it.
Clean dirt and grass off of the docking station using a brush.
Brush off dirt and grass from docking station, particularly around
parts on which the lawnmower rests and around the charging plug area:
Charging plug
Cleaning and checking
51