| 摘要 |
PURPOSE:To enable automatic detection of capacitance-lowered deterioration, by a method wherein an alkaline storage battery is divided into two combination batteries and the differential voltage between two terminals of the one is partially divided or amplified to correspond to the number of cells of the other. CONSTITUTION:When a charge current is turned on and off in steps by an on-off signal 10, a terminal voltage of a battery changes in steps as well, the change whose size is proportional to internal resistance. On the other hand, the number of cells contained in the combination batteries 21 and 22 are set at NU and NL voltages across terminals of batteries 21 and 22 when step-like changes occur at VU and VL. Then, first, when the number of cells of an Ni-Cd-battery pack 2 is even, the number of cells is divided so as to meet NU=NL. Then, for example, the size of change in the battery terminal voltage corresponding to 50% of capacitance-lowered deterioration is determined to obtain a set of reference values from this value and an actually measured value of VU-VL and it is fed to a comparator circuit 4. Thus, deterioration can be detected from changes in the output of the output terminal 7. When the number of cells of the battery pack 2 is odd, the output of an operational amplifier is multiplied by NL/NU times and the results are fed to the circuit 4. Thus, a capacitance- lowered deterioration can be detected.
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