Diagnostic system for a battery system

A diagnostic system for a battery system, the battery system having a battery module electrically coupled to a contactor, the battery module having first, second, and third battery cells, comprising:

• a first microcontroller obtaining a first initialization value and first, second, and third battery cell analog overvoltage flag values from a memory device;
• the first, second, and third analog overvoltage flag values being associated with the first, second, and third battery cells, respectively;
• the first microcontroller further obtaining a second initialization value, a first battery module overvoltage flag value, and a second battery module overvoltage flag value from the memory device;
• the first and second battery module overvoltage values being associated with the battery module;
• the first microcontroller initializing each of first, second, and third battery cell analog overvoltage flags to the first initialization value;
• the first microcontroller receiving first, second, and third output voltage values and a first battery module output voltage value from a second microcontroller;
• the first, second, and third output voltage values corresponding to first, second, and third output voltages, respectively, from the first, second, and third battery cells, respectively;
• the first battery module output voltage value being indicative of a measured battery module output voltage of the battery module;
• the first microcontroller setting the first battery cell analog overvoltage flag equal to the first battery cell analog overvoltage flag value if the first output voltage value is greater than a first threshold voltage value;
• the first microcontroller setting the second battery cell analog overvoltage flag equal to the second battery cell analog overvoltage flag value if the second output voltage value is greater than the first threshold voltage value;
• the first microcontroller setting the third battery cell analog overvoltage flag equal to the third battery cell analog overvoltage flag value if the third output voltage value is greater than the first threshold voltage value;
• and
• the first microcontroller transitioning the contactor to an open operational state if the first battery cell analog overvoltage flag is equal to the first battery cell analog overvoltage flag value or the second battery cell analog overvoltage flag equal to the second battery cell analog overvoltage flag value or the third battery cell analog overvoltage flag equal to the third battery cell analog overvoltage flag value;
• the first microcontroller initializing a battery module overvoltage flag to the second initialization value;
• if the first microcontroller determines that the first battery cell analog overvoltage flag is equal to the first battery cell analog overvoltage flag value or the second battery cell analog overvoltage flag equal to the second battery cell analog overvoltage flag value or the third battery cell analog overvoltage flag equal to the third battery cell analog overvoltage flag value, then:
• the first microcontroller determining a second battery module output voltage value based on a sum of the first, second, and third voltage values, associated with the first, second, and third battery cells, respectively;
• the first microcontroller setting a battery module overvoltage flag equal to the first battery module overvoltage flag value if a difference between the first and second battery module output voltage values is greater than a second threshold voltage;
• and
• the first microcontroller transitioning the contactor to the open operational state if the battery module overvoltage flag is equal to the first battery module overvoltage flag value.