Patent attributes
A charging control apparatus measures a first temperature of a first secondary battery selected from the plurality of secondary batteries, a second temperature of a coolant flowing into the cooling device, a charging current of the secondary battery pack, a first terminal voltage of the first secondary battery and a second terminal voltage of a second secondary battery closest to the cooling device, estimates a temperature of a temperature estimation point of the second secondary battery from a lumped thermal model having a thermal resistance between two points selected from the temperature estimation point of the second secondary battery, the first temperature measurement point and the second temperature measurement point, and measurement data about temperature, current and voltage, and determines the estimated temperature as a minimum temperature of the secondary battery pack, and varies a charging power provided to the secondary battery pack according to the minimum temperature.