Hey Razz i wanted to run this buy you. See if you think this sounds right.

Not trying to hijack your thread Hodag but i think this fits in and might help you as well.

I have the 08 LSV.

Stock came with 1 battery and i decided to option a sub woofer and duel batteries. My goal as i stated to them was i want to be able to hang out in the boat jamming out as much as i want and if the batter gets drained then be able to start my boat still. Paddled my dads boat a few times from a dead batter and it sucked and it was old speed boat weighting fare less then our Moomba's lol.

Anyhow there's a switch by my batteries. Battery1, Both, Battery 2.

Here how it works after much headache and trial and error.

Battery 1 is the factory Primary and runs the HU and starter along with all the boat accessories. Battery 2 has the Sub amp wired to it.

This is my findings after some headaches.

Switch Battery 1. Boat charges only battery 1 everything runs normal. After 10 hours or so sterio went to crap. Lost the sub completely and all my main speakers sounded low and muddy and the main amp was cutting off with only 20 on the deck volume.

Result = Battery two went dead because it wasn't getting charged. Charged it with my computer controlled charger worked great fixed all my stereo issues.

Switch Battery 2 Runs the boat and stereo just fine. I can run this till it kills that battery. Change switch to Battery 1 the boat starts right up. Batter 1 was at 50% though.

Now the thing that makes no since to me i guess is the switch in Battery 1 or 2 only charges that battery and still drain the other battery respective to its original wiring set up.

SO i was told on the water to keep the batteries in Both position this will charge both batteries and when i want to sit with no engine and listen tot he stereo for more then a few hours to change the switch to Battery 2 only.