6V Golf Cart Battery Upgrade

[Triumph]

May I suggest a good book for you to purchase. Nigel Calder's "Boatowner's Mechanical and Electrical manual". It is written for guys like us that are not engineers, or mechanics. It covers just about everything on your boat, including the answers to all of the questions you have asked.

Quick answers though: Tell you mechanic asking the series question "never mind". Golf cart batteries are made for more discharge cycles than std type batteries. They are preferred for the house bank for heavy discharging, and recharging. 4 of the these 6 V batteries fit into your current battery compartment, many of us use the Trojan T-105 battery. This will give you about 425 amp hours of electricity to run everything 12 volt on the boat, and 120 volt stuff through your inverter. That's a lot of battery power.

Most of us have installed a starting battery, this is one not meant for discharging but instead advertises cranking amps. We have installed this under the port settee, aft as far as practical, near the house bank. It's easy to run the wires as explained in other postings here. It is important too, to make sure the batteries are secure in place, and cannot come loose should the boat be put on her ear.

If you are a day sailor, with an occassional weekend out, the original battery configuration of two 4D Batteries should serve you well. That would be the easier way for you to go.

Good luck, and keep asking, that's how we all learn.

[tranquilcat42]

Thank you very much!!!!!

I appreciate the book reference and quick answers. Will let you know how it comes out.

Am trying to check if my 4D's could get me thru the summer and if so, would just add a new start battery, and re-wire

Teri

[jking]

Hi,
I replaced my batteries with NAPA 4D $180 each. Had to buy 4 post to nut conversion terminals as the batteries had posts instead of bolts about $6 each. They are the exact size as the old batteries. I think this is easier than putting in T105s and cheaper.
I took us 20 minutes to figure out that the batteries need to be on a 45 degree angle to take them out of the battery box as we mistakenly thought the batteries should be kept fairly level for installation.

Jan King Hull #303

[markws1852]

I recently replaced my 4Ds with Interstate 4Ds at $140 each--after returning the core of my existing 4Ds to the dealer. So far so good and a lot cheaper, I think, than Gels or other upgrades.

Mark Schlussel
Legal Tender III
Hull 300

[TBOT422]

We finally had to replace our original 4D's and opted for 2 pairs of 6V Golf Cart batteries from Sam's. The previous owner had put a pair of these and a 12V starting battery into the system before we bought it. We now have 690 AH of house capacity plus a reserve starting battery if needed.

[TBOT422]

One thing the previous owner did differently with the installation of the engine starting battery and third house bank than most configurations is that he maintained the isolation of each battery bank independently from each other through the addition of 2 more A-B switches. I suppose there are pros and cons to this arrangement versus a single large house bank of the same capacity, but since it was already there I left it as is. One of the advantages of this approach is that in the case of a failure of 1 of our 6 batteries in the house bank(s), I can easily isolate the bad battery and still have 2/3 of our house capacity. The disadvantage is that the operation is a lot more confusing as to which switch needs to be in what position to accomplish what you want to do.

I've cleaned up the schematic that the previous owner gave me as a Word document, and I'll try to post a scanned image of it below. If anyone wants a copy of the Word document to edit for their own configuration, just send me a private message and I will e-mail it to you.

[wolfe10]

Teri,

At least on ours two 4D wet cells under the seat at the chart table are the OE battery set up.

And yes, 6 VDC batteries must be used in PAIRS wired in series-- so 2,4,6, etc.

Many use golf cart batteries because they are one of the least expensive quality deep cycle batteries.

Are they the best-- NO, not in my opinion. Because the battery box/area is not vented, I use AGM batteries. They do not outgas unless extremely overcharged. In fact, they are legal to ship by air in the U.S.

So our house bank is two 4D Lifeline AGM's. Have an AGM starting battery as well in the next compartment forward of the OE battery area.

[saileagleswings]

The Catalina supplied 4D wetcell batteries lasted one year on our boat. I replaced them with 4D AGMs. They lasted 8 years. I just replaced them again this summer. I like AGMs partly becuase I don't have to add water or woory about acid fumes. Dividing the cost by 8, the cost per year isn't so bad.

I used the main halyard and an electric winch to move the batteries from the battery box to the deck. Then I used a plank to slide the batteries to the dock and onto a hand cart. The process was easier then I has imagined it to be.

Someone wrote something about replacing the Charles 30 amp charger with a 60 amp charger. Besides the wiring and fuses, one might want to check the air space and cooling requirements for the charger.

[jking]

I put NAPA 4D part number BAT 7266 batteries in $180 each and added terminals to the posts (about $6). They seem to work fine. NAPA also carries the 4D batteries with terminals instead of posts part number BAT 8274 for $204 (they didn't have any in stock when my battery died.) Jan #303

[nybor]

Wow. So many posts about batteries. I think my main question is, are two large12 VDC batteries more efficient that 4-6 VDC ones? Assuming cost/weight are not factors. That Nigel Calder book is fantastic by the way.

dave
NYBOR

[nybor]

Hi again. I just got off the phone with Lifeline. The tech said he likes the 4-6 combo (as do a lot of the posters), mainly because they will provide more capacity (a bit taller). The connecting cables - series - parallel setup, (i asked about losses) are not an issue, since the 12 V basically have the same connections, but inside the batteries - so no difference.
Thus, I am going to go the "light-weight" route. However, I am going to purchase the Lifeline AGMs.

dave
NYBOR

[solstice]

Hello,

I have a C355 and the battery box is quite similar to the 350. My OEM 4D's are getting to the point of replacement and I want to go with 6V's.
My question is does anyone have the height measurement of the C350 Battery Box? The dimensions of the entire battery box would be helpful as well. I would like to compare it to the size of my battery box to see if I have not only the height, but also the clearance for the Battery cables.
Thanks in advance...

[pdenoncourt]

In the C-350 battery space, it is not perfectly rectangular. You can fit a cube that is 22"L x 18.5"W x 12"D inside the battery space, but there is a half-inch lip all around the top, so you need to consider that in your planning. If you will be pitting in 4 6v batteries, you can slide them under the lip and lose only 0.5" off the length.

Hope this helps.

Peter Denoncourt
KITE, C-350 #72

[solstice]

In the C-350 battery space, it is not perfectly rectangular. You can fit a cube that is 22"L x 18.5"W x 12"D inside the battery space, but there is a half-inch lip all around the top, so you need to consider that in your planning. If you will be pitting in 4 6v batteries, you can slide them under the lip and lose only 0.5" off the length.

Hope this helps.

Peter Denoncourt
KITE, C-350 #72

Thanks Peter,

The 355 box dimensions are: 20.75x17x12 and the corners are rounded, but there is no lip. I know the Trojans are the shortest of the 6Vs, so I'm trying to verify if I have the room for 4. My box also has a chase for the cables below the 12" height. I am trying to post a picture, but I can't figure out how to compress enough to post. The message says 256K max. Any help with this would be appreciated...

[KenKrawford]

Just Google "compress jpg". There are many free online sites to compress an image.

[solstice]

In the C-350 battery space, it is not perfectly rectangular. You can fit a cube that is 22"L x 18.5"W x 12"D inside the battery space, but there is a half-inch lip all around the top, so you need to consider that in your planning. If you will be pitting in 4 6v batteries, you can slide them under the lip and lose only 0.5" off the length.

Hope this helps.

Peter Denoncourt
KITE, C-350 #72[/quote]
Thanks Peter,

The 355 box dimensions are: 20.75x17x12 and the corners are rounded, but there is no lip. I know the Trojans are the shortest of the 6Vs, so I'm trying to verify if I have the room for 4. My box also has a chase for the cables below the 12" height. I am trying to post a picture, but I can't figure out how to compress enough to post. The message says 256K max. Any help with this would be appreciated...[/quote]
Here is a photo of the 355 battery box.

batteryboxS.jpg (19.2 KiB) Viewed 19173 times

[pdenoncourt]

You may have just enough space for Trojan T-145 golf cart batteries, or equivalent. 1/8" to spare in the length. Here is a photo of my installation in my C-350.

[solstice]

You may have just enough space for Trojan T-145 golf cart batteries, or equivalent. 1/8" to spare in the length. Here is a photo of my installation in my C-350.

Thanks so much! This was the measurement comparison I was looking for. All of the pictures I've seen of the 350 battery compartment seem to show a good amount of space on one side with 6V's installed. Could you confirm that the depth of your box is 12"?
Really appreciate the help!

[Richard Thabit]

For what it is worth, my replacement 6 volt batteries are still working and while I do not have a photo of the installation, I have measurements of the batteries I installed back in 2007. Below is what I posted back in 2007. My boat usage is only 5-6 month and I am in a slip with shore power keeping the batteries charged. I use the tried and true method of odd-even days for use of my two battery banks, always having one charged , in case the one in use has been drained during sailing. I keep the water levels up by checking the batteries about twice per month. To tell the truth, I am surprised that they are still OK.


Past post:
I did not find a local place to buy Trojan T-105 batteries so I went to an Interstate distributor in Carlstadt, NJ. Last night I purchased 4 U2200 6 volt batteries which are slightly more powerful than the Trojan T-105's for $82.95 each. They are sold for Golf Carts and the distributor told me that many RV folks are doing this change too. They are labeled Deep Cycle "C3 Anvanced Capacity". Interstate took the old 4D's and gave me $35 each.
They measure 10 1/4" long X 7 1/8" wide X 11 1/8" high and based on my measurements should fit using flat nuts and washers in place of wing nuts.

Specs are: Ah 232; Reserve Capacity @ 25 A 474; Reserve @ 75 A 122.

I expect to install them this afternoon and will let you know what I needed to do to fit them.
Richard
THree Sheets
C350 #111

[pdenoncourt]

Confirmed, 12"depth.

Good luck with your installation.