Patent ID: 6998819

Claim:
A method of detecting a current leakage path in a high voltage battery pack having a plurality of serially connected battery modules, comprising: (A) connecting a first set of said modules into a first circuit containing a voltage measurement resistor; (B) connecting a second set of said modules into a second circuit containing said measurement resistor; (C) while said first set of modules is connected in said first circuit, simultaneously determining the voltage of each of the modules, and a first current flowing through said first circuit, and measuring a first voltage across said measurement resistor; (D) while said second set of modules is connected in said second circuit, simultaneously determining the voltage of each of the modules, and a second current flowing through said second circuit, and measuring a second voltage across said measurement resistor; and, (E) determining a leakage path resistance associated with said leakage path using the first and second currents, the determined voltages of the second set of modules, and the first and second measured voltages, wherein step (E) includes preparing a pair of lookup tables providing comparative data including the leakage resistance at each of a plurality of connection points to said modules representing potential current leakage paths.