When creating a Battery Management System (BMS), and the charger and gauge uses different communication protocols, such as Inter-Integrated Circuit (I²C) and System Management Bus (SMBus), the microcontroller unit (MCU) needs to interface between chargers and gauges, or needs a system that has different communication protocols for each device. This application note illustrates the use of MCU for a Smart Battery System (SBS) where the MCU polls the SMBus gauge, translates the received data to be compatible with the I²C charger (based on I²C specifications), and transmits to the I²C charger.