Abstract: Embodiments provide redundant voltage measurements for battery management systems. A first stack of battery cells is monitored with a first battery cell controller (BCC), and a second stack of battery cells is monitored with a second BCC. At least one battery cell is a common battery cell shared by the first stack of battery cells and the second stack of battery cells. For one embodiment, a single common battery cell is used. A failure of the first BCC or the second BCC is then determined based upon monitoring of the common battery cell. If failure is detected with respect to the BCGs, an action is taken to protect the battery pack including the first stack of battery cells and the second stack of battery cells. In addition, diagnostic voltage levels can also be used to facilitate the determination of a failure for the first BCC or the second BCC.