An overview of what DC Coupling is given by Jake Sherry and Kyle Willsey of Morningstar Corporation. DC Coupling refers to the method of taking direct DC energy and doing something useful with it, whether that be charging batteries or running DC loads. DC coupling can be used in an off grid system or in a grid tie with battery backup system. DC coupling is a much simpler layout, is easier in concept, better for batteries and scale-able, than AC coupling is. It causes a seamless transition of power during a power outage with a grid tie system.