Patent ID: 6933728
Filing Date: 2005-08-23
Classification: G01R

Abstract:
1. An apparatus for measuring a value of a battery module voltage, the battery module being included in a modularized battery of an electric vehicle, the apparatus comprising: a differential amplifier circuit for outputting a modified voltage difference, the differential amplifier having input terminals and at least one resistor, the modified voltage difference being obtained by modifying a voltage difference inputted through the input terminals on the basis of a gain according to the resistivity of the at least one resistor; an auxiliary power source for outputting a reference voltage; a first switching circuit for controlling applying of the battery module voltage to the input terminals; a second switching circuit for controlling applying of the auxiliary power source to the input terminals; and a controller for calculating the value of the battery module voltage on the basis of an output voltage from the differential amplifier circuit, wherein the controller performs: detecting a variable effective gain of the differential amplifier circuit; applying the battery module voltage to the input terminals of the differential amplifier circuit; detecting the output voltage of the differential amplifier circuit that is applied with the battery module voltage; and calculating the value of the battery module voltage by modifying the output voltage of the differential amplifier circuit on the basis of the effective gain.