BATTERY SYSTEM AND ASSOCIATED METHOD FOR DETERMINING THE INTERNAL RESISTANCE OF BATTERY CELLS OR BATTERY MODULES OF SAID BATTERY SYSTEM

摘要

A method for determining the internal resistance of battery cells of battery modules of a battery includes measuring a first voltage of at least one battery cell of a first battery module at a first time. The first battery module is decoupled from the battery module string in response to a control signal. The first battery module is connected to the battery module string after the first voltage measurement to enable a change in the first voltage of the at least one battery cell in response to a current flowing through the first battery module. A second voltage is measured at a second time where the first battery module is connected to the battery module string for a predefined time interval. The internal resistance is determined with reference to a difference between the first and the second voltage and the current flowing through the first battery module.