METHOD FOR DETERMINING AN OVERALL LOSS OF CAPACITANCE OF A SECONDARY CELL

摘要

A method for determining an overall loss of capacitance of a secondary cell, for example of an accumulator, which is brought about by ageing processes is provided. The overall loss of capacitance is determined additively from partial losses of capacitance which are determined by means of various parameters from various functions. A partial loss of capacitance is determined under constant peripheral conditions. If the peripheral conditions change, the partial losses of capacitance follow one another directly, i.e. with respect to the same loss of capacitance. The interval of the respective charge throughput rate is shifted here. The overall loss of capacitance of a secondary cell can be extended to the overall loss of capacitance of a package composed of a plurality of secondary cells.

主权项

1. A method for determining an overall loss of capacitance of a secondary cell upon passage of a first interval from a first initial value up to a first final value for a charge throughput, and of a second interval, following the first interval, from a second initial value up to a second final value for the charge throughput, comprising:
determining a first partial loss of capacitance for the first interval with the aid of the first final value by means of a first function which describes a relationship between the charge throughput and a loss of capacitance; determining a second partial loss of capacitance for the second interval by means of a second function which describes a relationship between the charge throughput and the loss of capacitance; and determining the overall loss of capacitance by means of adding the first partial loss of capacitance and the second partial loss of capacitance, the second interval being displaced for use in the second function in such a way that a result value of the second function for the second initial value corresponds to a result value of the first function for the first final value.