| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To estimate the charged state of a battery when turning a key switch on while reducing discharge amount (power consumption) of the battery during off-period of the key switch. <P>SOLUTION: During the off-period of a key switch, duration T of off-state is measured by a soak timer. When the key switch is switched from the off-state to on-state, the duration T of off state is multiplied by a predetermined dark current KIOPN to calculate the integrated value of charge/discharge current during the off-period of the key switch. The integrated value (minus value) of charge/discharge current during the off-period is added to the integrated value of charge/discharge current of previous time (when switched off) stored in a rewritable nonvolatile memory such as a backup RAM thus obtaining the integrated value of charge/discharge current of this time (when switched on). This integrated value of charge/discharge current is employed as the estimated value of charged state of battery (battery charging ratio SOC). <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
