One of the important key factors used in Electrical vehicles is Battery management System. The main part of the Electrical Vehicle (EV) that is strongly associated with vehicle safety and its range estimation using an optimizing cell balancing unit. This research work objective is to build a BMS that can be used in EV and provide better information to a user for monitoring the data. The paper illustrates the use of the ARM Cortex -R4 processor and BQ76942 battery monitor with their high-end features providing SoC, SoH, battery current, voltage, and thermal protection with the increasing range of EV using the cell balancing technique. The passive balancing using Coulomb Counting and EKF methods to estimate SoC for a battery pack give precise results for vehicle range extension The MATLAB simulation is done and proposed the cell balancing algorithm to improve the battery management system. Lithium-ion batteries are used due to their low weight and high charge density. The cells in the battery pack are monitored individually for their efficient operation and safety concerns. Also, for monitoring charging-discharging cycles, overcurrent undercurrent protection, and under-voltage overvoltage protection. For this purpose, the main microcontroller unit which is based on Advanced RISC Machine architecture is used. To observe and sense various battery management system parameters another BMS IC a highly integrated and high-accuracy battery protector and monitor connects with the main microcontroller to observe the battery pack determines various parameters and sends them to the main microcontroller. Some key simulation results to gain well cell balancing also ensures that the battery pack is neither over-discharged nor over-charged.