Cascaded H-bridge (CHB) converter is a suitable topology to integrate battery energy storage systems (BESSs) into the power system. Redundant submodules (SMs) are implemented in the CHB converter for higher reliability. However, in the literature, there is a dearth of dedicated research on the control of redundant SMs in this application. This paper proposes a control scheme for the redundant SMs in the CHB-based BESS. The proposed control scheme is able to safely activate and operate the redundant SMs that are not integrated with batteries. Simulation results are provided to verify the effectiveness of the proposed control scheme.