37 Installation, servicing, repair and retrofitting of electric apparatus for vehicles, in particular for rail vehicles, trolley buses, electric buses and hybrid buses; installation, servicing, repair and retrofitting of electric batteries for vehicles, in particular for rail vehicles, trolley buses, electric buses and hybrid buses; installation, servicing, repair and retrofitting of rechargeable electric batteries for vehicles, in particular for rail vehicles, trolley buses, electric buses and hybrid buses; installation, servicing, repair and retrofitting of chargers for electric batteries for vehicles, in particular for rail vehicles, trolley buses, electric buses and hybrid buses