what's up adam, how's my boat running?!
hope you're not logging too many hours this season!
what david and brett are saying is that all of your stereo equipment; the head unit, amps, eq, HSE, etc, need to be powered and GROUNDED to the stereo battery(ies). they all need to share a common ground otherwise, you'll have noise in your system; i.e., alternator wine, etc. it's easy really. i have a similar setup with the 1314 and 3 batteries (1 for boat, start, boat electronics and 2 for the stereo system). if your amps are already connected to the stereo battery, then you're halfway there. david may be able to offer other suggestions, but the easiest way (the way i did it) was to just re-run your head unit power and ground to the stereo battery directly and bypass your ignition. the upside is you don't have to turn your key to ACC to listen to the stereo with the boat off, the downside is, you have to remember to turn off your system at the end of the day. then all you need to do is invest in a good battery charger. get a good multi-bank one that you can either mount inside, or one that has quick connects with caps that you can quickly hook up back at home off the water. i cheaped out and bought a multi-bank battery tender off of amazon. david would say i'm selling myself short because the low amp rate (i think it's like 1.25A per lead) will allow my batteries to sulfate, re-charge slower and shorten the life of the batteries, but it's a shortfall i'm living with until i buy 3 new batteries. hope this helps a little. the 1314 does it's job for sure, just be sure to get a charger. i think when it comes time for me to buy new batteries, i'll buy 4 (3 for the stereo) a good high amp multi-bank charger and then just completely remove my stereo bank from the boat charging system (alternator).