A battery return disconnect (“BRD”) circuit for use with a battery supply having a plurality of electrically parallel inter-connecting batteries. The BRD circuit includes a plurality of DC input ports, a set of OR-ing diodes, a plurality of polarity detectors and a plurality of switches. Each input port includes a DC input terminal and a DC return terminal. Each OR-ing diode is connected to a DC input terminal or a DC return terminal and is forward-biased to when the BRD circuit is connected to a plurality of batteries having substantially the same voltage level. Each polarity detector monitors the bias of an OR-ing diode electrically connected to a corresponding DC input terminal. Each switch is connected to a DC return terminal and a polarity detector. Each switch is closed as long as the monitored OR-ing diode is forward-biased and open when the monitored OR-ing diode is reverse-biased.