Abstract: Various examples of the disclosure pertain to determining a set of calendar aging values of a test cell of a rechargeable battery, e.g., LIBs. The set of calendar aging values of the test cell of the rechargeable battery corresponds to a set of Temperature-State of Charge (T-SOC) value pairs. The set of calendar aging values of the test cell of the rechargeable battery is determined based on a battery-generic reference model for calendar aging of a (specific or random) battery cell and on a further set of calendar aging values of the test cell of the rechargeable battery. The further set of calendar aging values is obtained/derived from measurements of the test cell of the rechargeable battery and corresponds to a further set of T-SOC value pairs.

Abstract: The dependency of the open circuit voltage on the state of charge of a battery, i.e., the OCV curve is determined, e.g., to facilitate determination of the state of health or state of charge of the battery. The OCV curve is determined based on the values of multiple independent parameters, e.g., half-cell potentials derived from degradation modes such as loss of lithium inventory or loss of active material at the cathode or anode.