Battery-monitoring unit

The present invention relates to a battery-monitoring unit, comprising an interface which is configured to receive electrical voltages for each battery group comprising at least two battery cells being connected to each another in parallel and of a battery coupled with the battery-monitoring unit and comprising at least two battery groups, where an evaluation unit is provided which is configured to compare the voltages, received from the interface, of at least two series-connected battery groups with each another and to output a signal based on the result of the comparison.