Device for charging batteries of electric bicycles on a bicycle rack attached to a motor vehicle

The device (1) has a plug-in (2) inserted into a trailer socket (3) of a motor car. A connector (10) is mounted in an end of a connecting cable (9) for electrical connection of a battery. The plug-in is provided at an end of a housing (4). The trailer socket is formed at another end of the housing. The connecting cable laterally emerges from the housing. The plug-in and the trailer socket are rigidly aligned to each other. The connecting cable is designed as a coiled cable. A charging electronic unit (8) is arranged in the housing.