Replacing Batteries

[OS2Dude]

I'm sure this has been asked before in various ways, but a search returned over 20 pages of threads that mentioned 'battery' anywhere in them...

QUESTION:

Our 1985 Catalina 30 currently has two (2) 12v batteries that need replacing. We sail on a lake and have shore power for the big consumers. The main 12v stuff are electric head, bilge pumps, 'fridge (When disconnected from shore power) and cabin lights.

I'm thinking of getting four (4) of these: Duracell Ultra High Capacity 6V Golf Cart Battery
They are recommended replacements for the Trojan 125 batteries on the BatteriesPlus site.

Batteries Plus does not carry the Trojan brand even though they are listed as dealers on the trojan site and the two specialty golf shops on the list don't have prices. (I did send them emails for quotes)

What are your thoughts? Do I need four of them? Can my current battery charger (Guest 10amp dual battery) handle them if they are two banks of two? Should I make just one bank of four?

Thanks

 

[The Garbone]

460AH would be nice.

How you arrange the banks is really determined by what you feel comfortable with.

My only suggestion is pay attention size and fitment. I have all of my batteries in marine trays/boxes with tie down as to avoid spills and such.

 

[Stu Jackson]

What are your thoughts? Do I need four of them? Can my current battery charger (Guest 10amp dual battery) handle them if they are two banks of two? Should I make just one bank of four?

These links should answer your ???s. If not , come on back.

The All-Important Energy Budget:

http://c34.org/bbs/index.php/topic,3976.0.html

Record of Daily Energy Use of 100 ah per day:

http://c34.org/bbs/index.php/topic,6353.msg41471.html#msg41471

Largest House Bank 101 (by Nigel Calder)

http://c34.org/bbs/index.php/topic,5807.msg45046.html#msg45046

 

[OS2Dude]

Thanks Stu, those links were informative.

It seems a single large bank is better, and the largest I can afford the better. (So yes, all 4 batteries.)

Question remains about my current charger. It is a Guest 10 Amp dual charger, now made by Marinco. I think this is the unit they sell that replaced mine. Currently it is charging each of the 12v batteries separately. I assume if I make all four 6v batteries into one bank I would only use the one set of leads and tape off the second bank leads? Is it up to charging a large bank?

I remember seeing a post somewhere once about wiring multiple batteries into a single bank so the wires were as close to the same length as possible. Does anyone recall the URL for that?

Thanks.

 

[JK_Boston_Catalina310]

Thanks Stu, those links were informative.

It seems a single large bank is better, and the largest I can afford the better. (So yes, all 4 batteries.)

Question remains about my current charger. It is a Guest 10 Amp dual charger, now made by Marinco. I think this is the unit they sell that replaced mine. Currently it is charging each of the 12v batteries separately. I assume if I make all four 6v batteries into one bank I would only use the one set of leads and tape off the second bank leads? Is it up to charging a large bank?

I remember seeing a post somewhere once about wiring multiple batteries into a single bank so the wires were as close to the same length as possible. Does anyone recall the URL for that?

Thanks.

In short, no that charger won't do it and you should replace it even if it was the correct size because that type of charger will decrease the life of your batteries.

The marina I am at now is blocking MaineSail's personal website for some reason. But do a google search for "Compass Marine how to battery charger".

The general rule of thumb is to have a charger that is 10% of the battery bank. So for 4 6v GC batteries you will need a 50 amp charger. That link I sent gives you some recommendations on chargers.

I helped a friend do this install on his 1989 C30. The problem you are going to have is finding a space for the batteries. The battery box can only fit 2 GC batteries. On his boat he went for a bank of 2 6v GC for 230 Ah and then a reserve Group 24 battery. On my C310 I have 4 6v GC for 460 Ah but I am full time cruising. I am actually thinking of ways to add two more.

Good luck and fair winds,

Jesse

 

[OS2Dude]

At this time the batteries are located in the aft lazarette. The charger is there as well. This space is subject to sun exposure and is crammed full of spare life jackets, cushioned floor mats, etc.

After reading the material supplied above, it seems this is not the best location for batteries nor the charger. The only place that 'MAY' be available is under the quarter berth behind the diesel fuel tank. Would that be a safe place to put a few AGM batteries? That space is inside the cabin, which is A/C'd. But that space is inside the cabin, so any gassing would not escape easily.

Thoughts?

 

[Tally Ho]

The batts on both my boats Hunter 280 and now my O'Day 322 were in the cabin. In both cases, in the salon, so not where I slept, but still in the cabin. And neither of my boats were/are air conditioned.

I think a lot of boats have the batteries in the cabin.

Greg

 

[OS2Dude]

My concern is being directly behind the diesel fuel tank. Just want to make sure I wouldn't be creating a potential problem with that setup. The reason I'm thinking of moving them is the lazarette is full of stuff, so there is not much air flow, and it is exposed to direct sun so it gets pretty warm in there. I.E it is supposed to reach into the low 100s the next few days here...

 

[Joe]

If you were talking about gas instead of diesel tanks I'd be concerned, but you could always install some type of partition. The center of the boat is preferred location for heavy battery banks... shorter runs to the busses for one, plus it will improve your boat's ballast trim.

 

[The Garbone]

All my batteries are in boxes.
Link: https://amzn.com/B004W5SGBO
My start battery is next to the fuel tank, I would prefer it someplace else but it has to do. Hydrogen gas rises so as long as the tops are vented you should be ok.

 

[jeepbluetj]

Do you not have battery space in the bottom of the chart table locker? That's where Catalina put mine.
I have 2 GC6's in there and a small G24 for backup installed under the starboard settee.

140 watts of solar keeps it charged up when not at the dock.

 

[OS2Dude]

The batteries were under the nav station, but were moved to the aft lazarette when an A/C was installed there. Besides the fuel tank, only other possible location may be in front of the fresh water tank on the starboard side. Not sure if height of batteries will fit either location yet.

 

[danb2k]

This spring we replaced the 2 old 4Ds in our 2003 Catalina 36 with 4 Deka GC25 golf cart batteries. At 235 amp hours, the correct charger size would be 47 amps (10%), but due to space constraints we installed a Charles 40 amp charger (after the OK from my battery guy). So far things are great: Batteries hold their charge, and recharge quickly on shore power or our Honda EU2000i generator. I can recommend this approach.

 

[jeepbluetj]

I don't think you'll have room in front of the water tank. My G24 is where your water tank is and that's all the height I had. I couldn't fit GC6's in there.

AGM's on their side may be an option if it works for your budget. Putting 4 CG6s in the aft lazerette would worry me about weight all the way back there.