Packet and Management SystemsThe power and vitality necessities for a vehicle vitality stockpiling pack surpass what a solitary electrochemical cell or ultracapacitor cell can give{2. In this manner, ESS packs are planned with a basics of Electric Energy Storage Systems. On an average twelve cells are grouped in a module together to form a pack2.Some common topologies are :-1.Series only configuration-Used to elevate output voltage2.2..Series-Parallel  configuration-conceivably meet the power/vitality necessities for few time term2.3. Matrix configuration-sidestep a solitary open circuit & use the staying working cells2.Fig a) Series configuration ,b) Series configuration & c) Matrix configuration2.Key Aspect of Energy pack is Energy Management System (EMS)2. It performs some key functions like Cell estimations—for instance, voltage, current, temperature, and stress/strain,Pack estimations, Fault recognition, SOC, SOH, impedance, and limit estimation, ,Maximum power yield ability , Available pack vitality & Data logging, for instance, use history2.Cell BalancingCell adjusting is a strategy for planning more secure battery arrangements that broadens battery run time and in addition battery life4}. The basic wording to portray the cell balancing incorporates the utilization of terms active and passive2. The term passive is used to describe two scenarios both of which burn up the energy2. One is non controllable topology where cells are associated in arrangement and they can endure a slight overcharge.The cheated cells normally disperse vitality as a rule through the age of warmth. Amid this time, this enables different cells to make up for lost time in control. Resistors can be put in parallel to every cell to misuse any voltage/SOC contrasts among cells; contrasts in voltage will manage the rate of draining and cell charging driving the diverse cells to normally merge to an adjusted state2