------- BOAT Starting batteries. -- a discussion.
The 4D's & even 8D's are batteries that are very heavy to handle at way over 120 + lbs. or more each & who needs the aggravation of finding someone to help you move them around.
The big rig trucks & many boaters today are now going to a Group 31 battery & never look back. -- SKI in NC know what he is talking about.
There are a lot of good group 31 starting batteries with built in Stud terminals so no post adapters needed with up to 1,000 CCA's on tap and still priced very reasonable & if your really worried, put two in parallel & have more than you ever had with the 4D for your starting battery.
Newer technology that has been introduced in the Group 31's & is a big step above the 4D's & are cheaper, easier to handle, take up less space, have better warranties, and last just as long, if not longer.
OP - Doug Cole said "
I'm considering going to a group 31 start battery. CCA are very similar, it's 1/2 the cost, easier to install and takes up less space. I reckon that if needed I could always get a second G31 and parallel it, cost of two would be about the same as one 4D
." - and your thinking process stated above is right on target
. ----- There is no down side ---- ! -
---------------------- Make the move to G31's. --------------
I have converted my Kadey-Krogen 42 to all group 31 batteries for all my battery needs - be it usual starting
, typical house deep cycle
& Thruster AGM's
& have not regretted it.
---- In fact, I would never go back - it is that much better.
There is a good wide range of selection of different levels & types of G-31's out there, at every price point & quality level & battery type, so shop around & do your homework.
My recommendation is to go that route.
Good Luck with your project.