Modular unit connectable to a battery for monitoring its condition and protecting, including a housing which is directly connectable to the B battery posts of by means of receptor terminals clamped to said posts, the housing containing a first BD module, used to perform a disconnection of the supply of energy from said B battery; a second electronic module BM, used for a dynamic measurement of the B battery's state of health (SOH) and charge (SOC); a third electronic LCM module, used to control and manage all or part of the charges that supply said B battery, and a fourth electronic PDFS module, used to control the distribution of power supplied by said B battery.