6v vs. 12v? ; parallel vs series? need answers!

ok so im overhauling my battery system and im trying to figure out what to do. my boat came with only one battery and i know im going to add a perko switch and was originally gonna run four batterys in parallel for my stereo on their own bank and charge them at home after going out on the boat and have one battery for cranking. well after searching the archives for as much information i can i have found myself asking more questions than i have found answers. would it be better to run two 6v batteries than four 12v? whats the pros and cons between the two? and how would i connect the batteries together and whats the pros and cons between parallel and series? guess what im trying to figure out is what would be the best setup for what im wanting to do. i want to get the most amp hours i can get

Series pro - batteries will charge and discharge equally. Two Exide 145s will provide 245 amp hours.

Parallel pro - batteries will deliver more current during deep bass hits. Kinetik, Stinger, Odyssey, Surette, or Lifeline batteries work well. You are probably looking at 200-220 amp hours for two group 31 batteries.

It really comes down to electric capacity, budget, space, and weight when you are making battery decisions.

I previously ran two exide 145 golf cart batteries and currently run two Kinetik HC2400's. I think the Exides performed just as well as the much more expensive Kinetiks but I am reconsidering my charging regimen. I might not be injecting enough current into the batteries to get them to full charge?

I would isolate the audio/lighting bank from the starting/accessory battery and use a combiner for on the water charging needs.

Series doubles voltage, i.e. two 6V's are needed to equal 12V's

Parallel doubles Amps, i.e. two 12Vs will have double the Ah's of one 12V

If going the 6V route, you have to run 2 and wire them together in series in order to make 1 12V battery. If you go with 12V batteries, run them in parallel so they stay at 12V's.

6V con - big and heavy, not that heavy is a bad thing in a wake boat.

It depends on the discharge profile of each battery, so there is no right or wrong answer when it comes to 6v vs 12v. It comes down to your specific needs. If you have a huge alt and don't sit and chill for too long, you can get away with just a few batts. If you want to chill in a cove and crank it for four hours, you have to set it up differently. Also how much space they will occupy & how much they weigh is a factor.

You need to decide if you want to charge the stereo bank and isolate it when you stop or separate it altogether and charge at the house/dock. My stereo bank is separate from starting and I run 2 6v batts in series. I have 3 amps, 1 sub and around 12 cabin/tower speakers and I've never come back to the dock with stereo off. Post up your system or what you want it to be, and your specific needs. Lots of sound gurus on here to help.

I am looking to be able to sit in the coves and have the radio on for a while without it turning off. im not worried about the weight and i got a pretty good amount of space. i want to keep one battery for the cranking and then have the other battery system, whichever way i decide to go with it, by itself alltogether and charge it at the house. right now planning on running the wetsounds threesome with the sync 6 amp, then this winter i want to add the wetsounds interior speakers (3 pair) and a sub. havent quite decided on the amp for the interior speakers and the sub yet but i want to get my battery situation decided before then anyway.