A bidirectional communication channel between a robotic lawnmower and a charging station for data communication between the robotic lawnmower and the charging station. The communication channel includes a first interface provided on the robotic lawnmower and a second interface provided on the charging station. The first and second interface are connected to each other through charging contacts and configured to communicate data in a Direct Current, DC-balanced way. Each interface is provided with an inductor in a charging power path between the charging station and the robotic lawnmower. Each inductor includes a high impedance for enabling a high data transmission rate for frequencies above 50 kHz.