| 摘要 |
PROBLEM TO BE SOLVED: To enable highly accurate determination of full-charging, without relationship with change in charging conditions and characteristics fluctuations of an apparatus, by determining full-charging of a battery based on change per unit charging amount of terminal voltage or battery temperature. SOLUTION: A voltage detecting circuit 5 calculates change (dv/dAh) of a terminal voltage per predetermined unit charging amount. When a controller 8 determines that dV/dAh is positive peak value, it is decided that a battery the fully charged. Moreover, utilizing that a temperature detecting circuit 6 suggests that a battery temperature rises with drop of charging efficiency at the final period of charging operation, a controller 8 defines a point where an increasing rate dT/dAh of battery temperature per unit charging amount as the fully charged point. Therefore, since dV/dAh uses the relative change of voltage as a parameter in place of the absolute value of voltage, reliable operation can be realized regardless of voltage sensor error, dispersion or variation in battery characteristics. |
