Xplorer Series 12v/24v 20a MPPT Solar Controller with LCD Display 12v up to 260W systems and 24V 520w Systems.The Xplorer models have a current limiting function, you can connect twice the rated power to the controllerso if your on a budget you can use a smaller controller with more panels so that you get more power in winter or low light but dont risk overloading the controller in the summer.  The output will be limited to the max listed above.Xplorer series use advanced maximum power point tracking (MPPT) charge controllers, for off grid photovoltaic systems, with display unit.