Abstract: The disclosure describes systems, devices and methods relating to the charging of electrical energy storage devices on passenger buses. The disclosure also describes a passenger bus (30) comprising: an electrical energy storage device (34) for supplying electrical power to an electrical load (36); an interface (40) for receiving electrical power from an off-board source (42); and an on-board charger (38) electrically coupled to the electrical energy storage device (34). The on-board charger (38) is configured to convert electrical power received from the off-board source (42) via the interface (40) to a form suitable for charging the energy storage device (34).