Finished the system and it sounds great. Just had the weekend from hell in trying to get the boat started. Boat is equipped with SB Chevy and 2 x PC925 Odyssey batteries (Perco battery selector switch). Last time out ran battery one down to zip playing the system with the boat beached and later my kid ran battery two low while the boat was in my garage. Tried to trickle charge the Odysseys overnight with no luck. Tried to jump start boat with a new high output spare battery (via jumper cables) and again no luck. Finally had to have a commercial charger hooked up at 40 amps for four hours and got one battery fully charged and the other about halfway.
I'm hearing conflicting stories about how to live with this situation of wanting to deep cycle one of the batteries while beached and still bring it back without the hassles. Install built-in battery maintenance system such as Dual Pro? Toss the Odysses and go with Optima Blue Tops (much bigger and hard to find a spot to mount them)? Other???