Abstract: The invention relates to a system which includes: a plurality of batteries (B1, B2) connected in parallel by a pair of first (1+) and second (1?) power conductor, each battery being connected to a device (BMS1, BMS2) for managing the battery; a device (EMS) for global energy management; a generator (101) suitable for applying an alternating signal to the power conductors (1+, 1?); and a plurality of transmitter-receiver circuits (M) respectively connected to the various management devices (EMS, BMS1, BMS2), each transmitter-receiver circuit (M) being connected to the power conductor (1+, 1?) and being suitable, in order to transmit data, for switching the impedance thereof between the power conductors (1+, 1?) between two states, and, in order to receive data to detect whether a value representing the amplitude of the alternating signal on said power conductors (1+, 1?) is higher or lower than a threshold.