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This paper presents a novel magnetically coupled optimal bi-directional battery charging system. The proposed circuit acts as a current source, i.e., constant current (CC) mode with a controlled output current in case of deep discharge of battery and as a voltage source, i.e., constant voltage (CV) mode with a controlled output voltage for near 100% battery state of charge (SOC). The proposed circuit is universal from battery voltage point of view, i.e., can charge battery with any given voltage and adaptive from optimum charging requirement view point, i.e., can adapt to any optimum charging requirement. The presented solution uses a magnetically coupled bidirectional converter topology. In order to make the system feedback controlled during the whole cycle of charging, the regulation loop is clamped and hence automatic and smooth transition between the CC and CV mode is achieved without the need of any extra loop. Experimental and simulation results for 250 W prototype are presented to validate the proposed system.