| 摘要 |
PROBLEM TO BE SOLVED: To detect overcharge surely in charge control of a secondary battery by separating heat generation due to inner resistance of the battery from chemical heat generation due to overheat. SOLUTION: The charge controller for a secondary battery 10 comprises a section 12 for detecting the temperature every first predetermined time, a section 14 for operating temperature rise per unit time, i.e., temperature gradient, every second predetermined time longer than the first predetermined time based on a temperature detected at the battery temperature detecting section, and a section 16 for making a decision whether a temperature gradient operated at the temperature gradient operating section is higher than a threshold value predetermined depending on the charging state of the secondary battery or not. When a decision is made, at the temperature gradient deciding section, that the temperature gradient exceeded the threshold value continuously N times (N is a natural number), full charge of the secondary battery is detected. |
