The batteries that came with my boat are all cranking type (Interstate 27M-XHD) 800 CCA and 1000MCA rating (2 per engine). The genny has the same unit also. My question is was the boat delivered new with this set up or were these changed out prior to my 2009 purchase? The date tags were never punched and the warranty cards are still attached so I'm thinking they may be original to the boat. As I'm getting ready to replace them should I introduce a deep cycle to each engine in tandem with the cranking units?