My past battery problems mainly due to dirty or loose connections so I'm no expert. That said, I'd make sure connections are clean and tight, the water at the appropriate level and they're fully charged. If they don't hold a charge, I'd slap a load tester on them. You can pick up a functional unit from any auto parts store or Amazon.com for about $50-$60. The tester will tell if the batts are shot.

My Xantrex charger has an "equalize" feature that helps prevent premature batt death. You didn't say if you equalize or not. Here's some info on that subject: [url]http://www.xantrex.com/web/id/257/DocServe.aspx[/url]

When it did come time to replace them, I just did a straight replacement - 2 flooded 4D's for 2 of the same. I (rightly or wrongly) didn't think the extra capacity it was worth the hassle and expense of some major reconfiguration. My Honda genset makes up for "limited capacity". Hope this helps.

Marc
"Solla Sollew" #1473
Ventura

Next time I replace batteries I will probably go to 6v golf cart batteries adding two forward under the starboad seat.
Though I have noted that Costco is now stocking Optima marined 120 Amp hour batteries. These are spiral wound, pure lead sealed glass mat batteries. They are reported to have good deep cycle charicteristics and will accept high charge rates without damage. They are selling for about $120 each, about a dollar per amp hour. They are more compact than golf cart batteries and are not sesitive to mounting angle. If four were used it would create a 480 amp hour bank. Four golf cart batteried would create nearly double that but they are very bulky and would take some modification to install them. I think you could put four Optima's forward and four aft, that would be 960 amp hours for about a thousand dollars, if you needed that much reserve.

Do any of you have any experience with the Optima batteries? I do not.

For what it's worth, the batteries on my 2002 Mk II are stock 4Ds delivered with the new boat. Yep...still the original batteries, in spite of spending the first five seasons as a charter boat in the Pacific Northwest. A couple times a year I top the cells with distilled water, and check the specific gravity of the cells. Although I have a number of cells that are marginal on specific gravity, they still seem to hold a charge just fine. And I have the stock charger that came with the new boat, as well.

I have one practice that may be making a difference...I let the batteries rest. Only on rare occasions do I leave the charger on. Just this afternoon I went to the boat to check it, as we have been having very cold temps here in Oregon for almost a week. The voltmeter showed all batteries full charge. I ran the charger for about an hour while the Espar was warming the boat, but I made sure I shut the charger off (and the battery-driven Espar) when I left the boat.

I added four 6 Volt Golf Cart batteries to Gone with the Wind nearly 5 years ago. They received high recomendations because they can be discharged rather severly and recharged. They did cost a bit more but I am totally satisfied with their performance. I did several other things at the same time ie. add a Link battery monitor and change all the wiring plus a new alternator and regulator. Someday I will put together the story. There are several others in the old forum. One of the other reasons I used the golf cart battieries was by using four in series/parallel I could disasemble the bank in the winter and carry them off the boat and maintain at home. They do weigh about 60#s but lighter than the larger battieries. :) This also helped me with the listing problem that the MK1 has to starboard. I put all four battieries in the aft port setee. I have a backup 12V in the forward setee.

Gary,
I've never heard of a C36 with a stbd list. Mine and many others have had a port list, but yours is the first one with a stbd list, to my knowledge. Adding two batteries (one house, one start) to the stbd side leveled Julandra out perfectly.

On my '94 CAT M1.5 I have used 2-4d batteries and they have lasted between 5 and 7 years. The shore power is always plugged in as the fridge is always on at the slip. I try to alternate them; they have always seemed to work well. And I also have a slight stb list which I attribute to the weight of the heavy batteries on the stb side and the stb water tank.
Richard
#1347

Tom,
My error on saying/writing starboard side. It did list to port and when you calculate the water tanks, holding tank, galley favoring the port side it made sense to add the additional 240#'s to the starboard side. I believe when I inquired 2004? you responded I should keep all the beer etc. on the starboard side. Unfortunately Donna will only allow a bottle of wine, so I needed to come up with something else.
Gary

Happy New Year to everyone!!

For those of you who have installed 4 golf cart batteries in place of the original group 27's or 4D's, did you have to remove the original battery tray? If so, how did you do it?

I am going to be replacing the group 27's in our C36 #0949 with the golf cart batteries in the spring once the snow is gone and it warms up a bit. When I took the group 27's out in prep for winter storage, I had a look to see how difficult it would be to remove the tray as I don't think the golf cart batteries will fit the tray.

The tray appears to be potted in place and could be very difficult to remove. Any ideas?

Tom,
Yes you are going to have to pull the tray that exists and fabricate a new one. In my early reading I came across a suggestion that you make a model of your battery out of carboard. Make it an actual size. I made four as I knew that was what I was going to use. Immediately it showed that with the existing pan it would not work. I too wondered how hard it would be to remove the pan. I grabed the outboard edge and noticed it moved. Still not sure what would have to be done I anticipated that I would need to use a saws all and perhaps chisel some of the tray away. I made a decision to tug on the tray one time to see if it would come lose. I did, it did, and I ended up on the floor and scraped my hand as I exited the cavity. Inside after you pull it you will find that Catalina used a scrap block of teak and some goop to hold it all together. My boat hull # 1056 was manufactured in 1990. I'm not sure what they may of used at that time. Perhaps 5200 just not sure. Anyway I might suggest that you apply a heat lamop to the area and perhaps it will make the tug a little bit less.
Having said that then I designed my platform and figured out how I would secure it.
Another thing you are going to have to do is cut away a portion of the seat. You can get 3 batteries in the cavity but the fourth becomes impossible without altering the seat top some. Do not worry as it will not show.
I'm planning to write my installation up in 3 or 4 segments for the web page or newsletter. I will try to do this soon. I have some pictures and just need to sort them and write something up.
Gary

Happy New Year Tom.
In my case when I added golf cart batteries in 2004 I did not remove the original battery boxes. First see how much room you have at each end of the boxes and determine if one end can be enlarged. In my case I had 5/8" space available at the aft end of the boxes.The batteries I chose were US Battery US2200, same battery as Interstate U2200. These batteries measure 10 1/4" X 7 1/8" x 11 1/4h. When placing two of these batteries end to end, they measured 20 5/16" at the base. I had enough room to extend my boxes about 7/8". My old box measured 19 3/4" at the base.
I took my Dremel tool and a cutting disk and made a cut 2" from each end. My boxes were attached to a plywood platform with 3M5200, so I heated the ends and then pryed each end off with assorted prying tools. The ends were re-attached with 5200 on their plywood base and placing the new batteries in the enlarged box while the 5200 dried.After drying I removed the batteries and used glass- thickened polyester resin from an auto supply store to fill in the gap. Thickened epoxy would have been better. I then applied glass cloth and epoxy over the joint for strength. No problems after 5 seasons and a lot easier than trying to remove the entire box and building a new one.
My batteries cost $53.95 in 2004 and now cost $95 each. They were $150 just a few months back, but are coming down in price as lead continues to drop back to $.45/lb compared to its high in 2008 of $1.76. Wait till the last minute to buy your batteries because each shipment your dealer gets will be lower in price.
Attached is my completed battery compartment.

Jack F Stewart
1993 C36 #1233 "Windancer"
Port Clinton, OH

Jack & Gary:

Thanks very much for your input. I tried tugging on my battery tray to see if it would even move, but it seemed to be well anchored. I may end up having to cut it out, but i will try the heat lamp trick first. I made up dummy batteries using 1/2" styrofoam insulation to give me an idea of the fit.

Jack: Thanks for including the photo of your battery installation, it looks great! I am sorry that I didn't get to see your installation when you were at our marine this summer. Unfortunately my mast re-wiring project took longer than I had anticipated so we didn't get over to see you.

Gary: It would be great to see some pictures of your battery installation. If you wouldn't mine, when you get a moment, sending a couple to me. My email address is "[I][B]tgrover[/B] [/I]at [I][B]rogers[/B][/I] dot [I][B]com[/B][/I]"

Thanks very much for your help.

Bill,
With my golf cart batteries , they came with the shorter "M" post as to the standard "UT" post with threaded stud.
In regard to 4D deep cycle battery suppliers, Exide Battery, or Johnson Controls is by far the largest battery supplier in the US. Their line is called Stowaway Marine Deep Cycle rated at 160 Ah for the 4D.
Catalina used to supply their new boats with the Exide Nautilus Marine Gold deep cycle battery. Not sure what they supply now. Anyway, stick with the true deep cycle battery and not what some call marine and starting battery.

Jack F Stewart
1993 C36 #1233 "Windancer"
Port Clinton, OH

I don't know if it has been mentioned, as I only gave this lengthy thread a cursory scan; but I would recommend using some sort of plastic tray for the batteries. I have heard of the acid leaking out of them, and if they aren't in some sort of plastic bin the acid can eat up some of the interior fiberglass. Just my 2 cents!

Bill,
It has been a while since I did this project 2004. I used West Marine Seavolt Batteries 6 Volt Deep Cycle. When I made my platform it was 3/4" plywood and I allowed for the height. The 4 batteries consumed most of the area and to fit the 4th battery in you do have to cut some of the seat.

Hi Bill,
Have you been happy with the Deka's and did they fit in the trays ? My rough measurements look like my trays will have to be lengthened an inch and change. 

Best, Greg