Patent ID: 7962300
Filing Date: 2011-06-14
Classification: F02D,F02N,G01R,H01M,Y02E

Abstract:
1. A battery state judging method of a lead-acid battery loaded on a vehicle, comprising the steps of: obtaining, in advance, a DC internal resistance r calculating, in advance, a load R imposed at an engine starting time, using a following Equation (1), from an open-circuit voltage OCV calculating a DC internal resistance r of the lead-acid battery, using a following Equation (2), from an open-circuit voltage OCV and a lowest voltage Vst at an engine starting time, both measured when the lead-acid battery is in a deteriorated or insufficiently-charged state, and the calculated load R imposed at the engine starting time; and judging a state of the lead-acid battery by comparing the DC internal resistance r with the DC internal resistance r