Detection Device for an Electrical Energy Store of a Motor Vehicle With Dynamic Plausibility Checking

A detection device for an electrical energy store of a motor vehicle for detecting a fault of at least one energy storage cell of an interconnection of energy storage cells of the energy store, the detection device comprising:

• a current sensor configured to detect current values of the interconnection;
• a voltage sensor configured to detect cell voltage values of the energy storage cells;
• and
• a storage and evaluation apparatus configured to:
• receive the current values and the cell voltage values;
• temporarily store the current values and the cell voltage values over a predetermined time period;
• compare a respective dynamic of cell voltage curves obtained from the temporarily stored cell voltage values of a time period with a dynamic of the current curve obtained from the temporarily stored current values of the time period;
• and
• detect a fault of at least one energy storage cell on a basis of the comparison.

A method for detecting a fault of at least one energy storage cell of an interconnection of energy storage cells of an electrical energy store, the method comprising:

• detecting current values of the interconnection;
• detecting cell voltage values of the energy storage cells;
• receiving and temporarily storing the current values and the cell voltage values over a predetermined time period;
• comparing a respective dynamic of cell voltage curves obtained from the temporarily stored cell voltage values of a time period with a dynamic of the current curve obtained from the temporarily stored current values of the time period;
• and
• detecting a fault of at least one energy storage cell on a basis of the comparison.