The PBT-CCS-1 float current monitoring system is an accessory to the battery monitoring system. It consists of a current monitoring interface (CMI) unit and a float current monitoring sensor. The system accurately monitors changes in the DC charging current which are precursors of an impending cell failure, as well as AC ripple currents which are indicators of charging system problems. The system also detects reversal of current direction indicative of a discharge condition and provides an alarm indication if a discharge event occurs.