Patent ID: 9634361
Date: 2017-04-25
CPC Classifications: B60L,G01K,G01R,H01M,Y02E,Y02T

Claim:
1. A method for determining an internal resistance of battery cells of battery modules of a battery, comprising: measuring a first voltage of at least one battery cell of a first battery module of the battery modules at a first time, wherein the first battery module is decoupled from a battery module string in response to a first control signal; connecting, in response to a second control signal, the first battery module 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; measuring a second voltage of the at least one battery cell at a second time after the connection of the first battery module to the battery module string, wherein the first battery module is connected to the battery module string for a predefined time interval; and determining the internal resistance after the measurement of the second voltage of the at least one battery cell with reference to (i) a difference between the first voltage and the second voltage and (ii) a current value of a current flowing through the first battery module.