The Battery Management System is a critical component of any electric vehicle. It monitors the voltages and temperatures of the cells inside the high voltage battery to ensure they stay within their safe operating range. The battery on our car is composed of 600 cylindrical cells for a combined 6.5 kilowatt-hours at a maximum of 252 volts.
The BMS on our car is composed of 2 parts, the Battery Master Board and Battery Slave Board. The Battery Master Board houses the microcontrollers, pre-charge circuitry, shutdown circuit, and DCDC Converter. One of the microcontrolelrs runs the BMS application, and the other runs the Aux Monitoring Application. The BMS application processes the cell voltages, cell temperatures, and pack current to estimate the energy remaining in the battery and ensure that it is within it safe operating limits. The Battery Slave Board contains the circuitry that measures the cell voltages and temperatures.