A solar panel system for determining how many solar panels connected to a controller is provided. An electrical pathway connects the controller to at least one solar panel. A first resistance is associated with each of the at least one solar panel. An external environment resistance is defined by a cumulative presence of at least the first resistance associated with each of the at least one solar panel, wherein the external environment resistance is different based on a total number of the at least one solar panels connected to the electrical pathway. A second resistance is associated with the controller. The external environment resistance and the second resistance at least partially define a voltage divider to receive an input voltage and produce an output voltage. The controller is programmed to determine from the produced output voltage the total number of the at least one solar panel connected to the controller along the electrical pathway.