To provide a power control device which detects an open-circuit voltage of a battery 13 to prevent the power supplied to a load from becoming instable.

The power control device comprises: switching means, connected between a load 4 and a battery 13 supplying power to the load 4, which switches to establish or break electrical continuity; prediction means which, by predicting a load-power characteristic indicating the time series characteristic of power consumption of the load 4, predicts on the basis of the predicted load-power characteristic a charge/discharge power characteristic indicating the time series characteristic of charge/discharge power of the battery 13; detection means for detecting an open-circuit voltage of the battery 4; and control means for controlling the switching means. The control means determines from the charge/discharge power characteristic predicted by the prediction means a period in which the charge/discharge power of the battery 13 falls below designated power for a designated period to be a voltage detection period and breaks the switching means to detect an open-circuit voltage within the voltage detection period.