The lecture will provide an overview of lessons learned when designing battery thermal management systems for advanced vehicles. We will start by understanding where the heat is generated in a cell, the efficiencies of power and energy cells, and what type of battery thermal management solutions are available in today's market. We will then investigate three different battery pack thermal management strategies employed by the OEMs – water cooling, air cooling and active (vapor compression) cooling- and outline the advantages and disadvantages of each technology. We will also delve into the Department of Energy's extreme fast charging program describing how the cell and module thermal design needs to be improved to meet the lifetime and safety expectations of the consumer. Finally, we will introduce the ultimate thermal challenge – cells entering into thermal runaway and what strategies are being employed to control or mitigate this phenomena. In the end, we hope to show that energy storage systems are varied, and each application requires a unique thermal solution to address today's technological barriers.