A battery assessment station for an electric vehicle (EV) battery includes an impedance spectroscopy device that applies an electrical signal at a set of frequencies and measures the impedance response of the battery. A battery analyzer determines a battery parameter, such as remaining useful life or state-of-health, based on the impedance response. A fleet management system manages a fleet of EVs according to their determined battery parameters. For example, the fleet management system applies operational rules regarding the use or charging of the EVs in order to respond to battery degradation and improve battery life.