Refridgerator Upgrade

[Bad Obsession]

Has anyone added a Refridgerator to an existing Icebox in Catalina 30 MK II? I am wondering what a ballpark figure is to do this and how hard this will be.

What unit did you add and is there any thing that you would suggest?

 

[Stu Jackson]

Most Catalinas use the Adler Barbour Cold Machine

which draws 60 AH daily. The very best things, regardless of what brand of refrigeration you install, are to insulate the box and get the biggest house bank you can with a good charging source depending on how you will use the boat. That said, I've never insulated our box, but it works great. In hotter weather, we turn the fridge off at night and it stays cool. Unless you do so (turn it off), and also install LEDs or find other ways to cut your electrical consumption way down, you're looking at 100 AH per day, based on a reasonable energy budget (also discussed here). Given that load, you need a house bank of at least 200 AH to spend one night on the hook without having to recharge or discharge your bank more than 50% (ours is 360). Those are the big picture issues. Again, use the www.catalina30.com website for more boat specific information. I've already provided you with links to our C34 website Message Board for detailed electrical discussions about battery charging systems.

 

[Hayden Watson]

"I need more power Captin."

...you need a house bank of at least 200 AH to spend one night on the hook without having to recharge or discharge your bank more than 50% (ours is 360).

Stu, what batteries do you use to get to 360?

On my 88 C30, I currently have an AGM D4 with 200 ah for the house and a group 31 with 105 ah for the start. They are on separate battery switches but can be used to supply the other need when required. I use a battery combiner for charging and have a 105 Ample Power alternator. I would like to increase my house bank but can’t figure out where to put any more batteries. Ample Power recommends a storage capacity or 4x alternator output for best recharge. That means I should 420 minimum. Between the furnace and the refrigerator I can use all the capacity I can get.

 

[Stu Jackson]

Hayden, wwe have three 130 ah (each)

American Batteries from Hayward, CA. They're "about" a Group 31 physical size. As far as a house bank is concerned, more is always better with a fridge. You may be reading Ample's suggestions backwards. It's not that the house bank should be 4X the alternator output, but that the size of the alternator should be between 25 and 40% of the house bank size. You size your bank based on your loads and your recharge times. The acceptance of a battery bank of our size range (+/- 360 to 420+) is about 50A anyway, which is what an alternator of your size and mine can comfortably put out for good periods of time (see my threads and Maine Sail's discussions on "battery acceptance" here and on our C34 website).

Battery space on a C30 is limited by the OEM boxes, but I just know there are scads of C30 owners out there who have found more room and different places for more batteries - I just am not an expert in C30 layouts.

 

[Hayden Watson]

Thanks Stu.

My understanding of the 25% rule is to have enough storage that the alternator will stay in the bulk phase longer. My previous batteries were 3-G27 gels. They would hit the set voltage after only a few minutes of charge and then my 100 amp alternator would drop to 25-40 amp max. The AGM’s will take a lot more juice before starting to ramp down. I have been using my start battery for the first 4-6 hours after motoring then switching to the 200 amp house bank. It would be nice to add a second D4 and not use any of the start/reserve capacity. As it is now, if I don’t draw down the start battery, I hit saturation voltage fairly quickly and it limits how many amps I get.