In recent years, environmental pollution and energy issues have gained more attention. Li-ion batteries have gotten more attention recently due to their high energy density, safety, and low pollution. Therefore, building an accurate model is crucial and the battery management system (BMS) is crucial for the battery's safe operation. Accurate state of charge (SoC) estimation and protection of the battery are the fundamental functions of a battery management system (BMS), and it significantly improves battery life and enhances performance. The decision to use the first-order Thevenin equivalent circuit model for the cell model is based on balancing complexity with accuracy. Parameters such as open-circuit voltage (OCV), internal ohmic resistance, polarized internal resistance, and capacitance are crucial for characterizing cell behaviour. These parameters are determined using the pulse discharge method. These parameters complete the modelling of the battery. Managing both charging and discharging processes is one of the fundamental operations of BMS. Using a control circuit consisting mainly of universal logic gates this function is carried out, which is simple to develop and implement. In this paper, we will be focusing on the extraction of parameters using the pulse discharge method of a battery pack. And discharge and charge management using a control circuit in BMS.