A power conversion controller includes: a correction-value calculating unit that calculates a correction value DE2 to correct a voltage value BEFC from a voltage signal BEFC that is obtained by converting the voltage value BEFC detected by a first voltage detector into a digital signal by an A/D converter and from a series-total voltage value EBAT detected by a second voltage detector; a corrected-voltage calculating unit that calculates a voltage signal BEFC1 as a corrected voltage value that is obtained by correcting the voltage value BEFC by the correction value DE2; and a gate controller that controls a power converting unit based on the voltage signal BEFC1.