Method for determining the capacity of li-ion cells with the aid of distinct points

A method for determining a capacity of at least one lithium-ion cell, during open circuit voltage aging with the aid of at least one distinct point in at least one voltage curve during a charging process and/or in at least one open circuit voltage of the lithium-ion cell, comprising:

• measuring the at least one open circuit voltage of the lithium-ion cell or measuring the at least one voltage curve of the lithium-ion cell during the charging process of the lithium-ion cell;
• detecting the at least one distinct point of the at least one open circuit voltage of the lithium-ion cell or of the at least one voltage curve of the lithium-ion cell during the charging process;
• checking a shift of the at least one distinct point in at least one of the at least one open circuit voltage of the lithium-ion cell and the at least one voltage curve of the lithium-ion cell due to open circuit voltage aging;
• ascertaining the at least one distinct point in the open circuit voltage of the lithium-ion cell or in the voltage curve of the lithium-ion cell when a non-shift of the distinct point has been checked;
• and
• using the at least one distinct point as a state of charge reference point.