One embodiment of the present disclosure describes a battery system including a battery module with a first and second cell group connected in series; and a cell control unit communicatively coupled to a plurality of sensors, in which the cell control unit includes a first analog-to-digital converter that outputs a first cell group voltage; a second analog-to-digital converter that outputs a second cell group voltage; outputs a measured battery module voltage; and logic circuitry that determines a calculated battery module voltage based at least in part on the first cell group voltage and the second cell group voltage; and determines whether a fault is expected to be present in the cell control unit, the battery module, or both based at least in part on the measured battery module voltage and the calculated battery module voltage.