Patent ID: 8400163
Filing Date: 2013-03-19
Classification: G01R,H01M,Y02E

Abstract:
1. A voltage detecting circuit, comprising: a switch group that selects any one of a plurality of battery cells connected in series; a sampling capacitor that maintains a potential difference between a positive electrode terminal and a negative electrode terminal of a battery cell selected by the switch group; a measuring part that outputs a detected voltage value signal corresponding to a potential difference between ends of the sampling capacitor; a transfer switch that transfers, to the measuring part, the potential difference between the ends of the sampling capacitor; a correction capacitor provided in parallel to input terminals of the measuring part, and between the transfer switch and the measuring part; and a discharge switch provided in parallel to the correction capacitor, and controlled so that a switching condition of the discharge switch is mutually exclusive with that of the transfer switch, wherein, in the correction capacitor, a capacity value is switchable to a larger value in a case of a measurement of a battery cell connected to a high potential side of the plurality of battery cells, and wherein the capacity value of the correction capacitor is determined in accordance with a potential difference between a potential of a positive electrode terminal of a battery cell corresponding to a high potential side transfer switch, and a potential of a negative electrode terminal of a battery cell connected to a lowest potential side, the positive electrode terminal being connected to the correction capacitor.