Battery management systems with dual CAN messaging. In at least one embodiment of a battery management system (BMS) of the present disclosure, the BMS comprises at least two, dual, controller area network (CAN) transceivers, wherein a first CAN transceiver is for a vehicle bus and a second CAN transceiver is for a charger bus, and a computer program operable to communicate with the two, dual, CAN transceivers to toggle back and forth between vehicle intended, and charger intended, messaging states to improve battery operating efficiency.