Re: Battery Sizing - am I crazy?
You need to do something like I have in my 30' boat. I have a typical size 24 starting battery for my 2 cy Yanmar, then a separate house battery that is a true deep cycle battery. They should not be run together for house lighting etc needs. You might find depending upon useage, a size 24, 27 or 31 12V lead DCycle batter will work for your needs. If you are going say a week at a time, then yes, keep the 2 8D's if that is what you have. Reality is, my setup will work for what you have. I did have a size 24 for the house, recently put in a 31 for a few more AHrs to work with.
She drives me boat,
I drives me dinghy!