This is smart solar charge controller. You can connect solar panel. Battery. Load all together in the controller. Controllerhas the features to protect the battery from over change and low discharge. Controller has also facility to change phones. There are two USB plug of max 2.5 A currentrating for direct phone charging. Current Support - max 30A Means you can connect maximum load current or charging current of 30Amps. Simply 50 watts panel privide 1.5 A current. Like that you can connect all about 30A max.