Schoonertrash wrote:

The old boat had a couple of 4D's at 220 Amp each. The new boat is
currently using fairly standard 12 volt RV size batteries at 110 ratings
each.

I'm guessing Group 31s?


I'm thinking of going to the 6 volt variety as I have to go back up
to or near 400 Amp hours of storage. Which size, which voltage, and why?
If six volt are the fairly inexpensive one's from Costco (golf cart
batteries)useful or should I just spend the money at West Marine?

I'm not saying *don't* spend the money at West Marine, although I personally
would not. At WM you do get a better guarantee than you're likely to get at
any local battery discounter. But before you go seriously shopping for new
batteries, check into more info. Here are some links i found helpful when
pondering the same question earlier this year

http://bart.ccis.com/home/mnemeth/12volt/12volt.htm
http://www.marine-electronics.net/te..._faq/b_faq.htm

And in the end, since we already had the wiring & the cases for two Grp 31
batteries, I bought two Excide Grp 31 dual purpose (700 CCA and 115 AH each)
at Agri-Supply

http://www.agri-supply.com/

They have a big outlet which is not too far off our track from home down to
the boat. Unfortunately, the particular batteries I bought were at the end of
their shelf life and have not proved very satisfactory. Furthermore, they are
at or below the minimum bank we need for life a-cruising with our electrically
profligate lifestyle. My plan is to get two new Grp 31s for starting and short
term house loads, supplemented with a big bank of 6V golf cart type batteries
when I can get around to building in a case for them.

Another issue we pondered... the battery charger is a KEY part of the system.
You need to match your amp hours to your charging capacity. Another key point
is that a modern hi-tech 3 stage "smart" charger will be a zillion percent
more effective, and will dramatically increase the life of whatever batteries
you choose, than anything cheaper or older. We replaced a quite impressive
looking ferrous core charger than had been boiling away batteries at the rate
of one per year for the former owners. Plus it did not have an equalizing
function.

Fresh Breezes- Doug King