The invention relates to a device (710, 720, 730, 740) for monitoring an energy store (20; 30) comprising a plurality of battery cells (5001111-500klmn), which are arranged in a plurality of battery groups (2001-200k, 30011-300kl, 400111-400klm), and a temperature-control device for controlling the temperature of the battery cells (5001111-500klmn) by means of a plurality of partial flows of a temperature-control medium, each of the partial flows being associated with one of the battery groups (2001-200k, 30011-300kl, 400111-400klmn), characterized by: a plurality of sensor apparatuses (720) for sensing
temperature measurement values of the battery cells (5001111-500klmn), each of the sensor apparatuses (720) being arranged in such a way that the sensor apparatus can sense the
temperature measurement value of one of the battery cells (5001111-500klmn); an apparatus (710, 740) for determining a plurality of average temperature values from the sensed
temperature measurement values, each of the determined average temperature values being determined in such a way that the determined average temperature value is associated with one of the battery groups (2001-200k, 30011-300kl, 400111-400klmn); and an apparatus (740) for evaluating the plurality of determined average temperature values and, if one of the determined average temperature values exceeds a temperature threshold value, determining that the partial flow associated with the associated battery group (2001-200k, 30011-300kl, 400111-400klm) has a fault. The invention further relates to a
battery system, a vehicle, a method, a
computer program, and a
computer program product.