I am very impressed with the entire DJI FPV drone battery system. Batteries are "smart" and I thought it was a gimmick until I bought another battery. Batteries are firmware (I was told when I connected a newer battery to the drone) and know when to charge when they run out and this panel is used to decide who goes first (charges with the most charge left ). First). It is important to understand that this does not charge the batteries simultaneously, but sequentially in order of "fullness" from largest to smallest. Here's how it works. There's no power cord included, it's just a panel, you plug it into the charger where you would originally plug a battery pack. Good flight!