Abstract: Electric Vehicles [EV] of next generation are pushing the development of new battery technologies. To minimize cost and maximize efficiency, vehicle system should have full usable battery storage capacity. Remarkable progress has been achieved on battery technologies for EVs and HEVs [Hybrid Electric Vehicles]. Battery energy densities have steadily increased, and batteries today can be reliably charged and discharged thousands of times. If designers can effectively exploit these advancements in energy capacity, EVs and HEVs have the potential to be competitive with traditional vehicles in terms of cost, reliability, and longevity. An important consideration for the battery pack monitoring system is the communications interface. For communication within a PC board, common options include the Serial Peripheral Interface (SPI) bus and Inter-Integrated Circuit (I2 C) bus. Each has low communications overhead, suitable for low interference environments. Another option is the Controller Area Network (CAN) bus, which has widespread use in vehicle applications. The CAN bus is very robust, with error detection and fault tolerance, but it carries significant communications overhead and high materials cost. While an interface from the battery system to the main vehicle CAN bus may be desirable, SPI or I2C communications can be advantageous within the battery pack.

Keywords: Electric Vehicle [EV], Hybrid Electric Vehicle [HEV], Microcontroller, Controller Area Controller [CAN], CAN Gate way, CAN Bus, LTC6802 [Battery Monitor], Galvanic isolation transformer.