A battery system has a first cell balancing circuit and a second cell balancing circuit with a bus bar disposed therebetween. The battery system further includes an integrated circuit measuring a first voltage between two sense lines coupled to opposite ends of the bus bar while the first cell balancing circuit and a second cell balancing circuit are turned off, and determining a voltage value based on the first voltage. A microcontroller receives the voltage value and determines that an open circuit condition exists in the bus bar if the voltage value is greater than a threshold voltage value.