Ultimately the value and cost of energy storage depends on the performance of many cells within an end-use application. This requires attention to be given to system integration issues such as power converters, balancing circuits, and energy management (supervisory) charge/discharge control. These systems are not an afterthought, they are crucial for the safe and reliable operation of energy storage. Without their proper design, pack performance will be limited in terms of lifetime, capacity, cost and other metrics. Our research enables systems to last many years whilst always delivering optimum performance by developing new approaches for individual cell level management with decentralised control, fault detection approaches, and energy management systems that use intelligent forecasting and predictive charge control.