A power supplying system for supplying power in an electronic device includes a plurality of rechargeable batteries coupled to a functional block of the electronic device. The rechargeable batteries at least include a first battery and a second batter. In a normal mode, the first battery and the second battery are connected in parallel between a system voltage supplying node and a ground node, and in a charging mode, the first battery and the second battery are connected in serial between a charge input node and the ground node.