BATTERY PACK AND DETECTION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a method of detecting replacement of a battery cell used in a battery pack. SOLUTION: After charging or discharging a battery pack is started, a control part calculates the latest internal resistance Rnewof a secondary battery, based on the voltage value and the current value of the battery cell. Then, the latest internal resistance Rnew, that has been calculated, is compared with a previous internal resistance Rprewhich has been stored in memory. If the comparison shows that Rnewis smaller than Rpre, it is decided that the battery cell has been replaced; but if Rnewis larger than Rpre, it is decided that the battery cell has not been replaced. COPYRIGHT: (C)2008,JPO&INPIT