The large-scale integration of renewable energy sources presents challenges to the power grid due to fluctuations and uncertainties associated with these sources. To address this issue, battery energy storage systems (BESSs) provide a viable solution, with cascaded H-bridge (CHB) converters emerging as a preferred choice for integration. Nevertheless, the reliability of CHB converter-based BESSs remains a concern, necessitating cost-effective and efficient testing methods. This paper introduces the mission profile emulator (MPE) approach, which utilizes a simplified circuit to emulate actual mission profiles for testing an individual sub-module (SM). The proposed method employs a current generator with CHBs to improve the equivalent switching frequency. The SM controller, based on the state of charge (SoC) of the battery cluster, accurately replicates the charging and discharging characteristics in alignment with the actual system's behavior. Simulation and scaled-down experiments have verified the effectiveness of the proposed testing scheme.