A power control system comprises a power accumulating system including a storage cell charged with electric power supplied from a power generating system and supplying a vehicle with electric power, and a control device controlling a cumulative power amount that is an amount of electric power accumulated in the storage cell. The power control system accepts drive schedule data representing whether or not the vehicle is to be used during a predetermined period. The power control system charges the storage cell till the cumulative power stored in the storage cell reaches a first threshold when the drive schedule data represents the vehicle is to be used during the period, or otherwise, it charges the storage cell till the cumulative power stored in the storage cell reaches a second threshold smaller than the first threshold when the drive schedule data represents the vehicle is not to be used during the period.