METHOD FOR OPERATING AN ENERGY STORAGE UNIT, BATTERY MANAGEMENT SYSTEM FOR PERFORMING SUCH A METHOD AND ENERGY STORAGE UNIT WITH SUCH A BATTERY MANAGEMENT SYSTEM

The present invention relates to a method for operating an energy storage unit having a plurality of battery cells (1) electrically connected to one another, each battery cell comprising an over-voltage protection device and a cell protection, wherein an adjacent battery cell voltage (14) on each battery cell (1) of the energy storage unit is monitored to determine whether said battery cell voltage is larger than a predetermined cell voltage minimum value (16), wherein the energy storage unit is switched off when the battery cell voltage (14) drops below the cell voltage minimum value (16). Thereby the battery cells (1) are monitored with respect to a triggering of the respective over-voltage protection devices, wherein the energy storage unit is further operated if a battery cell voltage (14) of a battery cell (1) of the energy storage unit exceeds the cell voltage minimum value (16) and the triggering of the over-voltage protection device of this battery cell (1) is thereby detected. The present invention further relates to a battery management system configured to carry out the method and an energy storage unit with such a battery management system.