In Present scenario Internal Combustion Engines [ICE] is overcome by Electric Vehicles [EV] due to advantages like reduction in carbon-di-oxide [CO2] emission, cost. Advancement in electric vehicles are extensively going on and one such concept is Battery management system [BMS]in Battery Electric vehicle. In Battery Electric Vehicle there are many types of batteries and from the literature survey Lithium Ion Battery can be concluded to be suitable as it is advantageous in weight, cost, energy density and many aspects. The usage of Lithium-ion (Li-ion) batteries has increased significantly in recent years due to their long lifespan, high energy density, high power density, and environmental benefits. various internal and external faults can occur during the battery operation, leading to performance issues and potentially serious consequences, such as thermal runaway, fires, or explosion. In Battery electric vehicle Battery plays an important role. Battery may be overcharged or it may undergo faults. Hence a proper management system is required to control the Electric vehicle [EV] and it is called battery management system [BMS]. BMS has to be designed properly and major aspects to be taken care are State of Charge, State of Health, Cell balancing, Thermal heat dissipation, Temperature, Pressure.