Patent ID: 9116213
Filing Date: 2015-08-25
Classification: G01R

Abstract:
1. A secondary battery state detecting device detecting a state of a secondary battery mounted on a vehicle, comprising: a current detecting unit detecting a current value of a current flowing in the secondary battery; an extreme value detecting unit detecting a first extreme value of a current flowing in a starter motor after an inrush current flows from the secondary battery to the starter motor after electricity to the starter motor starting an engine is turned on based on the current value; an inflection point detecting unit detecting a first inflection point of the current flowing in the starter motor after the inrush current flows based on a minimum value of a variation of the current value per a predetermined time; and a calculation unit selecting the inflection point when timings when the extreme value and the inflection point are detected are separated for a predetermined time or more, and selecting either one of the extreme value or the inflection point in the other cases to set as a starting current, and calculating a starting voltage being a voltage necessary for starting the engine from the starting current, an internal resistance of the secondary battery, and a voltage before starting being a voltage of the secondary battery before the electricity to the starter motor is turned on.