In some examples, apparatus comprises a multiplexer (MUX) adapted to be coupled to a set of battery cells and configured to provide a voltage of a different battery cell in the set of battery cells based on a MUX control signal. Apparatus comprises a comparator coupled to the MUX and configured to compare a MUX output signal to a threshold voltage to provide a comparator output signal. Apparatus comprises a digital control circuit configured to provide the MUX control signal to the MUX, to store the comparator output signal, and to use a logic AND gate to provide an AND gate output signal based on the stored comparator output signal.