Battery Packs

The key enabling component in electric and hybrid vehicles is the battery pack. Higher power density and lower cost lithium battery systems have transformed the way that we can store and use power on board a vehicle. Going back to early electric vehicles, heavy lead-acid batteries were used but they simply did not have enough storage capacity per unit of mass to be effective except in some special smaller applications like forklift trucks and milk floats. After these, we then had more advanced energy storage systems such as NiCad batteries and then NiMH batteries. There were also attempts at using molten sodium salt batteries but these had many issues as the electrolyte needs to be maintained at a very high temperature to maintain its conductivity. The step change was brought about with the invention of commercially viable lithium-ion battery chemistries that offered significantly improved energy storage densities and power factors that made them very suited for mobile applications. We have talked about lithium battery cells in previous white papers and podcast episodes so please check these out for more information. Lithium battery cells have some significant challenges that require a sophisticated electronic control system known as a Battery Management System or BMS.