An electrical control system is provided. A first slave IC generates a first message indicating that a first battery cell has an overvoltage condition that is received by a communication IC. The communication IC sets a fault line coupled between the communication IC and a secondary microcontroller to a first logic level indicating that an overvoltage condition has been detected. The secondary microcontroller sends a message to a primary microcontroller indicating that the overvoltage condition has been detected in response on the fault line having the first logic level. The primary microcontroller commands a contactor control system to set each of the first and second contactors to the open operational state, in response to receiving the message.