Changing refrigerator

H

Hap-E-Cruzer

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Need suggestions,
We have a 42 foot Sea Ray with one under counter fridge and one under counter freezer. They are 120v only. We have to run the generator to keep things cold and we spend a lot of time on the hook or away from the marina. Even while underway we must run the generator. Seems very wasteful. We were originally going to install an inverter and additional battery bank but have been rethinking this situation. Both units are eleven years old and who knows how long they will last.
So my question is :has anyone changed over to 12v DC/ 120v AC units with success. It would be easier and cheaper to change both units than install an inverter ( I think ).
Those of you who have 12v/120v units, do they do a good job when on 12v.?
Should I install extra batteries if I go this route? Can I just add two more batteries to the existing system and stay with non-deep cycle batteries like I currently have. I just replaced all 5 batteries last month with maintenance free group 31 batteries.?
Help????
 
Here's a very recent thread where something similar was discussed: http://www.boatered.com/forum/topic.asp?TOPIC_ID=153314

I've got a 12v freezer and a 12v refrigerator. With my solar array, it's rare I ever have to run my generator any more. If the replacement units are 12v compressors, they'll run fine on 12v and then they'll have transformers to turn 110-120v into 12v when you've got shore-power. However, you're going to need deep cycle batteries either way you do it (inverter or 12v appliances). Are those group 31 batteries starting batteries? Usually group 31 are deep cycle or combination. What exact batteries did you buy? Do they show an "amp hour" or "ah" rating on them? If so, it would be around 100 hours and that would mean they're fine for deep cycle service. If this is the case, I would suggest adding a decent pure sine wave inverter to your existing appliances. With a pure sine wave inverter, your old appliances won't even know they're not getting generator or shore power (but with a cheaper "modified sine wave" inverter, they won't run as well and it will be harder on them). I would further suggest you have your batteries set up so that you group 3 of them together for the house bank and keep 2 isolated for starting. You could also use 4 for house and keep 1 for starting. These options would give you either 300 or 400 amp hours which will easily get you through the night without running a generator, and might even make it close to 24 hours. You will want to add a battery monitor, though. Something good (like a Xantrex Link Lite or Pro) so you know how much charge is left in the batteries. If they're flooded/wet-cell, you do not want to take them below 50% before recharging.

That's must my 2 cents on your question. As always, opinions will differ.
 
Agree with Kurt above. It doesn't really matter WHAT type of unit you use, you STILL have to provide energy for it.

An inverter requires batteries, but so does a 12v unit. So while the 12v MIGHT be more efficient, you still need to install batteries if you don't want to run an engine or generator. It'll be a lot less expensive (not to mention less work) to install the inverter and keep the 120v units you have.

Another thought... if you now have the generator you probably have several other appliances that also require 120v, such as a coffeemaker. They'll run off an inverter, but not off 12v DC.
 
+1 to all of the above. Add to that, Sea Ray builds boats from the bottom up. The units were more than likely put in prior to the boat being buttoned up with the deck and helm. There is a possibility the units will not fit out the door without some disassembly of either the boat or the fridge.
 
Google NovaKool, they make a lot of side by side refrigerators and refrigerator freezers in dual voltage.
I have the 7600 side by side in my boat and we never have battery problems or run down a 700 ah house bank if I
run the genny 2 hours a day which I need for hot water anyway.

rs7600.jpg


www.novakool.com is the manufacturer.
The cruisair distributor in Danaia FL warehouses them.
 
Batteries are Napa group 31---1050 cca ah not listed. There are five of these and at this point I don't know how many or which ones are house related. Still researching....
There are 2 for each engine and 1for gen......
A good point brought up is removal of old fridge and freezer,
Doorway is only 22inches wide...just went through this trying to remove the Splendide washer/dryer....PITA
Now researching NovaCool ..seems to be only option but unsure about 12v only or 120/12v
Keep suggestions coming
Thanks
 
A quick bit of research shows that a NAPA battery is most likely made by East Penn (AKA: Deka, Duracell, West Marine branded batteries). What is the exact model number? You can call East Penn with the model number and they'll tell you if you've got dual-purpose batteries. If you do, you're good to go for 12v appliances or an inverter.

I'm a firm believer in the KISS method of doing things as well as "if it ain't broke, don't fix it".

If it were me, I'd opt for the inverter, keep your current appliances, and use a pair of those engine batteries as my house bank (perhaps alternate which pair gets house duty every so often). Then I'd have it wired so I could bring the other pair online in case the batteries are run down too far to start the engine who's batteries are pulling the house duty. That's back-up number one. Back-up number two is the generator who's battery is isolated and can be started to charge the house bank.

I'm going to guess that one pair of your engine starting batteries are wired as house. If you can't find that out from Sea Ray or on a Sea Ray forum, use a volt meter. Turn off the charger and turn on some house loads. You'll see a voltage drop in the batteries that are wired as house.
 
Thanks Kurt,
Did the volt test and it appears that both engine banks are also house bank. The gen battery is isolated and does not change with house loads. That's good. I will try to find out if the batteries are ok for this purpose. We are strongly considering the Nova Kool 12v fridge and leave batteries as they are. I could add another battery to each engine bank real easy if needed.
The new Nova Kools pull less than 5 amps each and we would be running the gen a.m and p.m. anyway for an hour or two.
 
If battery space isn't a problem, I would cnsider the addition, but suggest a 4D or something with higher AH. We. have a larger 12/120, and I changed that house bank to a group of 6V's to increase AH. Ours works well on 12 .
 
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