The spacecraft’s (SC) electric power system (EPS) is one of the vital systems. It could limit the SC capabilities or reduce the SC lifetime. The EPS should provide the required energy for the SC loads to perform their tasks successfully until End-of-Life (EOL). Furthermore, the EPS should guarantee the power needed to execute the customer requirements under all degradations (battery degradation, radiation, etc.) and other external factors (orbital degradation). The SC’s primary power generation sources are solar arrays and storage batteries. This paper investigates a SC with a Nickel Hydrogen Storage Battery (NHSB) consisting of 17 cells: 4 measured cells and 13 unmeasured cells. In this paper, two distinct objectives have been achieved: The first objective is formulating a control algorithm for battery testing and reconditioning (CABTR). This algorithm is applied to an NHSB in an orbital setting mode, rectifying the memory effect in the NHSB and restoring the battery’s total capacity. The second objective constructs an environment that effectively simulates the dynamic behavior of the battery during in-orbit operations. This simulated environment calculates crucial parameters such as the state of charging (SOC), battery temperature, voltage, and pressure of the NHSB during reconditioning. This computational analysis assures the robustness of the CABTR, and confirms the optimal battery performance. Subsequent validation encompasses ground tests and real-time telemetry data, which affirms the battery’s dynamic behavior and the developed algorithms’ efficacy.