400-Watt 12-Volt Off-Grid Solar Premium Kit w/ 4-Piece 100W ...
As for this question, if you are looking for the efficiency of the solar panels themselves it has a Cell efficiency of 22% which pertains to the ability of the solar panel to convert sunlight into electricity which is the watt rating of this solar panel (100w each). As for charging efficiency, the one that handles that is the Solar charge ...