| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a charge rate estimation apparatus for a battery, which is capable of more accurately estimating a charge rate of the battery even if a current stops flowing after charging/discharging. <P>SOLUTION: A charge rate estimation apparatus for a battery includes: first charge rate calculation means 4 for estimating an open-circuit voltage value OCV from a terminal voltage V determined by at least terminal voltage detection means 2 and calculating a first charge rate SOC<SB POS="POST">OCV</SB>of the battery 1 based on the estimated value; second charge rate calculation means 5 for integrating a charging/discharging current value I detected by charging/discharging current detection means 2 to obtain a current integration value and calculating a second charge rate SOCcoulomb of the battery 1 based on the obtained value; and charge rate switching means 6 for determining whether a current that flows just before a state where a charging/discharging current is not flowing, is a charging current or a discharging current, to select a smaller value of either the first charge rate and the second charge rate in the case of a charging current, and to select a larger value of either the first charge rate and the second charge rate in the case of a discharging current, to define the selected charge rate as a charge rate SOC of the battery. <P>COPYRIGHT: (C)2012,JPO&INPIT |
