[btrayfors]

Yes, there are several more sophisticated external regulators which could maximize the charging capacity of your alternator. However, they are expensive and, as you seem to depend on solar anyway, I'd add some solar capacity and a good little solar regulator. That would be less expensive and would ensure your new grp 31 batteries stay topped up.

Bill

 

[btrayfors]

Hugo,

If you have room for them, two 6-volt golf-cart batteries in series would be preferable to two 12-volt batteries in parallel. Virtually no 12-volt batteries are true deep cycle. The golf-cart batteries have thicker plates, are more robust and forgiving and have more AH capacity.

Two golf-cart batteries would give you 225-240AH capacity.

I recently found the very excellent U.S.-made Crown 235AH industrial batteries (white with red top) for under $100 each. Replaced the 8-year old T-105s in my boat. So far, so good.

Bill