Battery is considered the most dominant energy storage device for renewableenergy-based DC microgrid systems (RE-DCMG) because of its ability tostore energy for a longer duration. Here the power electronic converter playsa vital role, which acts as a bridge between the energy storage system and DCmicrogrid. One of the main reasons for the failure of battery systems due tothe failure of the power electronic converters. To improve the redundancy andconverter failure issues of battery energy storage systems (BESS), paralleloperation of multiple converters are required. However, the parallel operationfaces an issue of voltage imbalance between the converters which gives rise toan input circulating current. To address these issues, in this paper, we proposea nonlinear droop control based parallel DC-DC boost converter for battery energy storage system. The nonlinear droop control strategy ensures theequal battery current sharing between the parallel converters and good outputvoltage regulation. Moreover, SOC based controller avoids over-charging andover-discharging of the battery and the parallel converters ensure the redun-dancy in operation. The proposed system is designed and implemented in theMATLAB/Simulink and compared with the existing linear droop control.