Method for Determining a Capacity of a Battery Cell, Evaluation Device, Monitoring Apparatus, High-Voltage Battery and Motor Vehicle

• Main Authors: FRIEGEL, Armin, KREPPOLD, Bernhard, RIEMANN, Philipp, SCHWEIGER, Benno
• Format: Patent
• Language: English
• Published: 04.02.2021
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC EQUIPMENT OR PROPULSION OF ELECTRICALLY-PROPELLEDVEHICLES; ELECTRICITY; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES, IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PERFORMING OPERATIONS; PHYSICS; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY; TESTING; TRANSPORTING; VEHICLES IN GENERAL

A method determines a capacity of a battery cell of a high-voltage battery of a motor vehicle. The method receives at least three open-circuit voltage values of the battery cell; determines state of charge values of the battery cell from the open-circuit voltage values on the basis of a predetermined open-circuit voltage curve; forms at least two pairs of values by combining in each case two of the at least three open-circuit voltage values; determines respective charge throughput values of the battery cell which are specific to the pairs of values by integrating a measured current of the battery cell over a period between two measuring times of the associated open-circuit voltage values; determines respective capacity raw values which are specific to the pairs of values on the basis of the associated charge throughput value which is specific to the pairs of values and the associated state of charge values which are specific to the pairs of values; and determines the capacity on the basis of the at least two capacity raw values which are specific to the pairs of values.