BATTERY CONTROL DEVICE AND LEARNING METHOD

To secure the accuracy of each sensor although using inexpensive sensors.SOLUTION: A reference voltage sensor measures, as reference voltage, voltage of an accessory battery that supplies power to an accessory machine mounted to a vehicle. A first voltage sensor and a second voltage sensor measure a respective electric potential at both ends of an accessory machine power converter provided between the accessory battery and the accessory machine. A third voltage sensor measures an electric potential of a charging/discharging switch for switching a charging/discharging state of the accessory battery. A learning part learns an error included in a respective measured value of the first voltage sensor, the second voltage sensor, and the third voltage sensor on the basis of the measured value of the reference voltage sensor. Further, the learning part learns an error, if a first condition under which the first voltage sensor, the second voltage sensor, and the third voltage sensor respectively are equipotential relative to the reference voltage sensor, and if a second condition under which an electrification current amount of the accessory battery is not more than a predetermined value, are satisfied.SELECTED DRAWING: Figure 2 【課題】安価なセンサを用いた場合であっても、各センサの精度を確保すること。【解決手段】基準電圧センサは、車両に搭載された補機へ電力を供給する補機バッテリの電圧を基準電圧として計測する。第１電圧センサおよび第２電圧センサは、補機バッテリと補機との間に設けられた補機電力変換器の両端それぞれの電位を計測する。第３電圧センサは、補機バッテリの充放電状態を切り替える充放電スイッチの電位を計測する。学習部は、第１電圧センサと第２電圧センサと第３電圧センサそれぞれの測定値に含まれる誤差を基準電圧センサの計測値に基づいて学習する。また、学習部は、基準電圧センサに対して第１電圧センサと第２電圧センサと第３電圧センサとがそれぞれ等電位となる第１条件と、補機バッテリの通電電流量が所定値以下となる第２条件とがそれぞれ成立した場合に、誤差を学習する。【選択図】図２