The object of the invention provides a power supply and battery arrangement for feeding a solar tracker. In first aspect of the invention an encompassing a main electronic board, capable of operating autonomously as a charger up to a maximum input current, and auxiliary electronic boards, hereinafter modules, which are connected to the main electronic board to expand the range of current input is provided. Several of these modules, auxiliary electronic boards, may be arranged at the same time to increase the input current. In a second aspect of the invention a method for feeding a solar tracker using control loops is provided.