Battery

[blairm87]

Hi everyone. New to the site and what a wonderful site it is! I recently purched a 1968 36' Columbia with an atomic 4; beautiful and classic with 1 previous owner. Not a whole lot of bells and whistles on the boat; x2 12V batteries flanking the engine used to start, power the few lights on board, bilge pump and running water. 1 battery is out. Any suggest on the best battery to purchase? I also have 2 100w solar panels.
Thanks, pleasure to be on this site (new to boating, originally from country in Illinois, always been hands on with farming equipment, boats...not so much, ha).
Mitchell

[joe_db]

What kind and size battery came out?

[Sam]

I have similar boat and vintage - 1966 Morgan 34 and have always had two deep cycle batteries alternating between starting and house. Used different batteries over the years and have had good luck with the name brands. Group size 27 or 31 depending which fit into battery case/bracket. I really like Optima Blue Top dual purpose marine size D34. I have one that is 10 seasons old and still test out very strong. Just bought another new one to replace 12 year old Delco Voyager [which was still testing good]. Cost $263 on Ebay delivered. They are physically a little smaller, about 10 lbs lighter, easier to handle in tight spaces, more deep charge cycles and more cranking amps and reserve capacity. Maybe a little overkill but out on the water "it is better to have and not need than to need and not have".

[blairm87]

Yes, I've also been alternating between starter and house. The alternator on the A4 is not functioning too well...so I've really been relying in the solar power to keep the good battery functioning well. I will take your advice and purchase the battery you suggested. I also like to function maintaining over preparednesss; especially cruising in a '68 boat on the Pacific outside of Newport Beach, CA. The battery that's caput is a Everstart Group Size 29DC, 845 MCA.

[Al Schober]

My recommendation is to keep the start and house batteries separate. A group 24 is all you need to start the A4. House bank - whatever you need.
My Tartan 30 evolved over the years from 2 of Group 27 with an A/B switch to 1 of Group 24 (engine) plus 2 of Group 31 (house). Both were on On/Off switches, and the alternator ultimately fed the house bank. A combiner brought the start battery online for charge when the house back was up to voltage. I did buy one of those fancy 'state of charge' meters, but I think it was a waste of money. A good digital voltmeter and a shunt type ammeter (on the house bank) are all I think is needed.

[blairm87]

Thanks, Al. Sounds like a combiner is very important for me to have, especially if I go with a group 24 as the engine and a group 29 for the house...which is plenty for my house load. But I do worry about an over charge from the alternator and damage that could do to batteries over time. I think this is a very beginner type of question, but should that be of great concern? If so, how to prevent a well functioning alternator from pumping too much charge into the house/engine battery?

[Al Schober]

Yes, an alternator with no regulator can fry batteries. The alternator can be as simple as an on/off toggle switch in the field circuit (YOU become the regulator). Most alternators have a regulator either internal to the case or attached which might fill your needs. At the other end of the scale are external 'smart' regulators which have a 3 stage cycle. Check out the offerings from the folks at Balmar.