Battery
Just make sure that your battery is full of water if not a gell battery then charge it until it is fully charged approximately 12.5 volts disconnect from any loads clean the battery connections and store in a cool place. I leave mine disconnected in the boat. By the way the story about not storeing on a concrete floor is not true today with modern battery construction but if bothers you and you take them out of your boat just set them on some plywood or a board.