Man that bug has been going around.
Being an an aluminum boat and if you are going to install the charger directly to aluminum instead of wood or something, make sure you isolate not only the charger from directly touching the aluminum but the mounting screws as well. Many of people just isolate the charger with plastic washers and not the screws. The problem with this is the screws are touching the charger which are also touching the aluminum. I have pics posted of what I did in the main forum in the onboard charger thread.