The system has an electronic unit (30) including a circuit board and a temperature measuring device with infrared temperature sensors (32) arranged on and operatively connected to the circuit board to measure temperature of a predetermined measurement region on a surface of battery cells (13). The infrared temperature sensors are thermally decoupled from the circuit board. An insulator is arranged between the battery cells and a side of the electronic unit, where the side faces the battery cells. The insulator thermally decouples the infrared temperature sensors from the cells.
