Abstract: A battery system that has a doubled power supply than the conventional ones is provided. The battery of the invention has a first, a second, and a third electrode plates, each of which is electrically connected to electrodes on the housing of the battery via a first, a second, and a third conducting poles respectively. A first and a second separation plates are interposed between the first and the second electrode plates, and between the second and the third electrode plates respectively. The system utilizes a control to switch between the conduction between the first and the second conducting poles, and the conduction between the second and the third conducting poles.