Patent ID: 6522361
Filing Date: 2003-02-18
Classification: G01R

Abstract:
A residual battery quantity calculation apparatus for calculating a residual battery capacity of a battery pack of a plurality of battery pack types from which is obtained variables including a residual battery capacity which is the remaining capacity of the battery pack, a charging/discharging current which is the present charging and discharging current value to/from the battery pack, a battery cell voltage which is the present voltage of the battery pack, and a value for operational state flags which designate an operational state of a device, said device being powered by said battery pack, said apparatus comprising:communication means for receiving the variables from the battery pack; and calculation means for calculating the current residual battery quantity every time one of the operational state flags are changed based on the residual battery capacity, the charging/discharging current, the battery cell voltage from said battery pack received by said communication means, and said operational state flags, wherein said calculation means varies at least one variable in dependence on the type of battery pack, and the battery pack includes: measurement means for measuring one of the variables; means for adjusting a unit of measurement of the measurement means for measuring the one variable according to a measured level of the one variable; and means for outputting a correction coefficient used for calculating the residual battery quantity wherein said calculation means calculates the residual battery quantity and factors the result by said correction coefficient and wherein said correction coefficient is a temperature dependent coefficient.