The boat has some aftermarket amps which are mounted in front of the battery access. I can move them somewhat, but cannot get a good view of the battery set up. However there appear to be too full size batteries and one smaller battery. However, I am unable to get specifics concerning the types of batteries at this point. I also can't tell what the set up is in relation to the switch. However, from what I can tell, the two larger batteries appear to be linked together.