When I needed to replace my 4D batteries (and they were an interstate battery)...I elected to go with 4 6V deep cycle "golf cart" batteries. To do that I had to remove the "battery trays" Catalina installed ( 2 wood screws each) since the 2 golf carts are a tad longer side by side than one 4D battery so they would not fit in the tray. I simply put in some web strapping for each battery to hold the new batteries in place. I also had to make a couple of jumpers since you have to put 2 of the 6V batteries in series to get 12 volts.

I did the same on my C30....The golf carts are, in my opinion, far better deep cycle batteries than anything you can buy in a 4D size. I also have never had an issue with starting the diesel engine using them either.

Good luck,
Sean

The golf carts are also a lot easier to lug around.

[QUOTE=mtnguy;649]I guess I could run my reefer but that would run down even the best of Deep cycles in short order.
If they hold up for another 10 years, Ive done good.[/QUOTE]

With 2 4Ds you have almost 400 AH in your house bank (assuming you have a separate reserve emergency bank, formerly mis-called a start bank). The fridge uses 60 AH per day. With almost no other loads, with your new LEDs, you cold go two nights on the hook without having to recharge (by limiting yourself to a 50% discharge). Hard to understand the concept behind your approach, but I guess those without fridges learn to live with it. Those with them usually use them and learn how to manage their electrical systems.

10 years is great, but I don't connect it to lack of use. That's what batteries are for, to use.:)

Stu,

I just replaced my 4d's with the Deka commercial 4d. This is the same battery that West Marine has listed as their Sea Volt dual purpose wet cell. My local commercial auto/industrial dealer had them in stock so I went the easy route instead of the golf carts and the redesigning of the battery trays. In my research, I looked at the Exides also. Go to Exide.com and pull up their battery specs, and you'll see the Nautilus NG-4d 4d's listed with these specs, CCA @ 0= 600,CA @32@75amps= 850, RC min @ 25 amps = 250, and rated @ 160 AH. The Exide commercial battery Com-4d-p is rated higher for cca and ca's at the same levels, but is not rated in AH's. The Deka was rated about the same as the Exide commercial. My dealer said the commercials are what he puts in most boats around here. I also called the dealer in Annapolis that put in my original 4ds, and he said that's all he puts in the boats he supplies there. He doesn't put in the true deep cycle ones unless requested, saying the commercial ones do the same job, are rated higher, and are cheaper. I'm not so sure this is true, but at least now that I have replaced mine, I'll be able to tell exactly how long they'll last. Next time I can make the decision to do differently or not. Hopefully after at least 5 years.
Now, I also found wet cell true deep cycle batteries at Mid State Battery in Connecticut that are true deep cycle and rated at 205 AH's. They were just a bit more in price, but the shipping was prohibitive. These Mid States are the same as the Defender deep cycle ones in their catalog. Defender's are expensive, plus the shipping.
The discussion underthe heading "Batteries" also in this thread gives all the pros/cons of golf carts too.
By the way, I still have not found the correct maunal for my model of the Link 2000 you helped me with last fall. I must have the original Link 2000 monitor, that they improved upon very quickly, and destroyed all evidence of the old one. Thanks again for your help, and all the info you provided.

Bill

I was able to get good replacement batteries from NAPA Auto at a lot less than what West Marine was asking.

Chuck Parker

I seem to get 4-5 years my 4-d's. They seem to still have life but when new I can site for a solid 2 days at anchor without charging. I now can only get a little over a day. I do pretty much abuse them in the we anchor out about 90 nights a year and do a lot of charging in the 40-80% range. I'm not sure 6volts or agm's would get me much,plus my boatyard pulls and reinstalls them over the winter so I don't have to manhandle them. I do buy my batteries from them as the price is pretty comtpetitive.

Gunkholer - Have you ever equalized your batteries? Se: [url]http://www.amplepower.com/wire/eql/index.html[/url] That's one of the reasons that happens, plus chronically undercharging batteries or leaving them somewhat discharged. If you don't have a battery monitor, at least for your house bank, I strongly urge you to invest in one. The amount of power that goes back into batteries takes a long time because of battery acceptance - they take less as near full charge. Try downloading and reading the ample power primer at [url]www.amplepower.com[/url], technical documents. You should get a lot more from your batteries.