METHOD FOR DETECTING CHARGED STATE OF BATTERY, METHOD FOR AUTOMATICALLY STOPPING AND STARTING ENGINE FOR VEHICLE UTILIZING THE SAME, DEVICE FOR DETECTING CHARGED STATE OF ENGINE FOR VEHICLE PROVIDED THEREWITH BATTERY, AND DEVICE FOR AUTOMATICALLY STOPPING AND STARTING

摘要

PROBLEM TO BE SOLVED: To reduce the cost required for detecting the charged state of a secondary battery by eliminating the need of separately providing a current detecting element at the time of detecting the charged state of the secondary battery. SOLUTION: In a nonvolatile memory 13, the data about the average current consumption of loads 4-1 to 4-n and an ECU 9 and the data indicating the discharge characteristic of an on-vehicle battery 1 are stored. A microcomputer 10 in the ECU 9 detects the presence/absence of conduction to the loads 4-1 to 4-n and estimates the discharge current of the battery 1 based on the detected results and the data about the average current consumption stored in the memory 13. The microcomputer 10 detects the charged state (SOC) of the battery 1 based on the relation among the estimated discharge current, the terminal voltage and temperature of the battery 1, and the data indicating the discharge characteristic the battery 1 stored in the memory 13, and controls the operations of an engine 5 based on the detected results.