There is a request for charging and discharging of a lithium-ion battery with as less degradation as possible. In an operation using only binary values as in conventional technology, however, in a charged state in which the battery is used, there is a high possibility that the battery is used toward accelerating the degradation thereof. In a power distribution device for distributing power between a plurality of batteries and a plurality of customers, when distributing the power of the batteries to the loads of the customers, by being based at least on the degradation information of the batteries, the state of charge, and the temperature data of the batteries, a battery discharging function is achieved that makes the degradation of the batteries minimum.