POWER SUPPLY DEVICE

PROBLEM TO BE SOLVED: To provide a power supply device that is enhanced in calculation precision for the deterioration state of a battery.SOLUTION: A power supply device has plural batteries for outputting power to a load, a sensor electrically connected to the batteries, plural first switches each of which is connected between the load and each battery, power consumption estimating means for estimating consumption power consumed by the load out of the power of the plural batteries time-sequentially, and control means for managing the residual capacity and deterioration state of the plural batteries, and controlling the first switch on the basis of the detection value of the sensor. On the basis of the residual capacity of each of the plural batteries, the control means calculates output-possible power which can be output from the plural batteries to the load, and selects, from the plural batteries as cut-off batteries, batteries which can be cut off from the load to the extent that the output-possible power is equal to or more than consumption power, makes current to flow among the plural cut-off batteries under the state that the first switches connected to the cut-off batteries are turned off, and calculates the deterioration state of the cut-off batteries. 【課題】バッテリの劣化状態の算出精度を高めた電源装置を提供する。【解決手段】負荷に対して電力を出力する複数のバッテリと、バッテリに電気的に接続されているセンサと、負荷とバッテリとの間にそれぞれ接続されている複数の第１スイッチと、複数のバッテリの電力のうち負荷により消費される消費電力を時系列で推定する消費電力推定手段と、センサの検出値に基づき、複数のバッテリの残容量及び劣化状態を管理し、第１スイッチを制御する制御手段とを備える。制御手段は、複数のバッテリのそれぞれの残容量に基づき、複数のバッテリから負荷に対して出力可能な出力可能電力を算出し、出力可能電力が消費電力以上となる範囲内で、複数のバッテリのうち負荷から切断可能なバッテリを、切断バッテリとして選択し、切断バッテリに接続されている第１スイッチをオフにした状態で、複数の切断バッテリ間で電流を導通させて、切断バッテリの劣化状態を算出する。【選択図】図１