Battery Management Systems (BMSs) play a key role in the performance of both hybrid and fully electric vehicles. Typically, the role of the BMS is to help maintain safety, performance, and overall efficiency of the battery pack. One important aspect of its operation is the estimation of the state of the cells, to support functionalities such as balancing technologies and predictive energy management. Estimation of the State of Charge (SoC)/State of Health (SoH)/Thermal State of the battery play a crucial role in combination with the BMS power electronics. However, understanding the complexity of the interaction of these systems in combination with validated cell models remains an area of active research. To efficiently develop these control strategies, model based development techniques are employed combined with test results. This paper presents an approach to the assessment of cell balancing system functional specifications analysis, and BMS functionality development with respect to capacity utilisation, given differing levels of SoC estimation.