AC/DC Refrigerators

[cpaharley2008]

Wow,
Those are some neat units and the technology being used is unbelievable, with 12v air conditioning and lithium batteries and fuel cells in lieu of gas generators, amazing. Now explain to me why Aussies and Canadians do not exchange this technology in order to bring it to the North american continent??

[escape artist]

Originally Posted by cpaharley2008

Wow,
Those are some neat units and the technology being used is unbelievable, with 12v air conditioning and lithium batteries and fuel cells in lieu of gas generators, amazing. Now explain to me why Aussies and Canadians do not exchange this technology in order to bring it to the North american continent??

Hi: cpaharley2008... We don't have enough SUN!!! Alf
escape artist N.S. of Lake Erie

[Brian B-P]

Originally Posted by rbryan4

... A 12 Volt deep cycle battery has six cells that each output approximately 2.12-2.15 Volts. Generally, the the larger/heavier the lead plates in the cells are, the longer they will last, and the more deep cycle discharges/recharges they will take. The 6 Volt batteries have 3 cells instead of 6, even though their outer dimensions are roughly the same. Most 6 volts batteries therefore can use larger plates, and will last longer in a deep discharge/recharge situation - like an RV.

There isn't one (or any fixed number) of plates per cell, so dividing the plates in the box by the number of cells in the box doesn't say anything about the plate thickness. The plate thickness is chosen to suit the severity of service (as mentioned above), and is the same in any voltage of battery in the same product line. Fewer cells in the same size box just means more plates in a cell.

I should have said "6V or 12V doesn't matter to total capacity within batteries of the same construction". In fact, I did earlier...

Originally Posted by Brian B-P

... For the same total weight and bulk in the same range of batteries (same type and quality), it doesn't matter electrically whether they're split up in groups of three cells (6V) or of six cells (12V).

The usual problem is comparing apples (general-purpose batteries, most often 12V) with oranges (heavy-duty deep cycle batteries, very often 6V but availalble in 2V, 4V, 6V, 8V, and 12V). In practice, most 12V batteries sold for RVs are not the best heavy-duty designs, and the most readily available reasonably priced heavy-duty batteries are in 6V models.

Originally Posted by rbryan4

PS - it's also one of the reasons the 6 volt batteries are widely used in applications other than an RV where deep discharge and recharge occurs frequently - like a golf cart.

The standard equipment from most golf car manufacturers, according to online specs from them last year, an option is six 8-volt batteries, in series for a 48-volt system. For 1/3 more capacity, at the expense of 1/3 more weight of batteries, is eight 6-volt batteries for the same system voltage. Voltage doesn't matter - construction, total amount of lead, and being able to lift each box in the set are the determining factors. Since 6-volt batteries are common, and are usable in a 12-volt system (unlike 8-volt batteries), they are a good affordable choice for RVs.

[Brian B-P]

Originally Posted by cpaharley2008

Wow,
Those are some neat units and the technology being used is unbelievable, with 12v air conditioning and lithium batteries and fuel cells in lieu of gas generators, amazing. Now explain to me why Aussies and Canadians do not exchange this technology in order to bring it to the North american continent??

The EFOY fuel cells - which are methanol-fueled - are available in Canada and the United States. I've seen them at RV shows here, carried by a ordinary RV dealerships. They're expensive to buy, and expensive and inconvenient to fuel, but they are interesting... and maybe a good match for a compressor-type refrigerator (because they have constant low output to match the round-the-clock demand of the refrigerator).

[hotfishtacos]

Used RM8551 available soon...

Well I pulled the trigger today and ordered a new 7.3 cuft Nova Kool RFU8520 DC compressor refrigerator for my 19' to go in where my RM8551 (4.3cuft) is currently installed. This new unit has a 5.7 cuft refrigerator and a 1.6 cuft freezer with two doors. It is wider and taller than the RM8551 unit and I will lose my microwave (no problem!) and will have to do a fair amount of fine woodworking to make the new cutout but I am good with this stuff. I will pick it up locally around the end of November and then start a new thread on the installation. When finished the old RM8551 will be available...:

Steve

[rbryan4]

Originally Posted by hotfishtacos

Used RM8551 available soon...

Well I pulled the trigger today and ordered a new 7.3 cuft Nova Kool RFU8520 DC compressor refrigerator for my 19' to go in where my RM8551 (4.3cuft) is currently installed. This new unit has a 5.7 cuft refrigerator and a 1.6 cuft freezer with two doors. It is wider and taller than the RM8551 unit and I will lose my microwave (no problem!) and will have to do a fair amount of fine woodworking to make the new cutout but I am good with this stuff. I will pick it up locally around the end of November and then start a new thread on the installation. When finished the old RM8551 will be available...:

Steve

Good to hear Steve. I'll be very interested in the fridge's actual duty cycle and power consumption, since we'll have the same solar and battery setup you have.

[hotfishtacos]

Originally Posted by rbryan4

Good to hear Steve. I'll be very interested in the fridge's actual duty cycle and power consumption, since we'll have the same solar and battery setup you have.

I carry jumper cables...just in case!!..

[Jubal]

7.3 cuft Nova Kool RFU8520
Is this model number correct ? I cannot find this model on their web site.

Nova Kool, refrigerators, freezers, Marine, RV, Truck

[hotfishtacos]

Originally Posted by Jubal

7.3 cuft Nova Kool RFU8520
Is this model number correct ? I cannot find this model on their web site.

Nova Kool, refrigerators, freezers, Marine, RV, Truck

Sorry, RFU8320 not 8520.

[Jubal]

Thank you for the correction. I admire your initiative !

[alanmalk]

Originally Posted by rbryan4

Good to hear Steve. I'll be very interested in the fridge's actual duty cycle and power consumption, since we'll have the same solar and battery setup you have.

If Steve doesn't mind another question: Noise level? Not much space between the frig and the bed. (I take earplugs when camping. Would like to avoid that in my trailer.)

Thanks!
Alan

[Kountrykamper]

Originally Posted by hotfishtacos

Sorry, RFU8320 not 8520.

Will it fit through the door?

[hotfishtacos]

Originally Posted by alanmalk

If Steve doesn't mind another question: Noise level? Not much space between the frig and the bed. (I take earplugs when camping. Would like to avoid that in my trailer.)

Thanks!
Alan

Hi Alan! I plan to heavily insulate the back cavity and sides of the refrigerator which should deaden a lot of the noise. I may further isolate the compressor mounting if it is a problem. What is nice is that I can run it on the bench before installation to watch and listen to it operate.

[hotfishtacos]

Originally Posted by Kountrykamper

Will it fit through the door?

..21 3/4 deep through my 22" door opening...made it by 1/4"...

[Kountrykamper]

Deleted

[hotfishtacos]

Originally Posted by Kountrykamper

Check the spec sheet again

Looks like the

The RFU 6200/6800 is 20 1/4"
The RFU 8320 is 23 1/4"

...read it again..23 1/4 wide and 21 3/4 deep...it will go in sideways..

[Kountrykamper]

yelp saw that and had already deleted the post.

Your opening must be different then mine. 23 1/2 would not fit between my bed and closet wall without talking all the framing out. Will be interested to see how it turns out. Take lots of pictures.

[hotfishtacos]

Originally Posted by Kountrykamper

yelp saw that and had already deleted the post.

Your opening must be different then mine. 23 1/2 would not fit between my bed and closet wall without talking all the framing out. Will be interested to see how it turns out. Take lots of pictures.

This will involve some major surgery on the enclosure which I am equipped for and have experience doing fine woodworking. There is a lot of unused space in the wall between the 4.3 unit and the bed. I will grab all the room I can there. The microwave space will be used but the refrigerator is slightly shorter than the top of that space so the top gap will be finish trimmed. If the left wall of the closet needs to move a little..no problem but I don't think it will.. The framing will be just a strong but much thinner when I'm finished.

The two most important goals of mine besides doing a nice installation;
1. Heavily insulating the venting space behind the refrigerator with polyisocyanurate insulating board and adding really quiet, low power fans to move air though that space, maybe mounted on the backside of the lover vent cover. We'll see. This will insulate the venting area well and reduce noise significantly. One really nice aspect of this model refrigerator is that the DC compressor unit will be directly behind the lower vent cover, readily accessible.
2. I will install wiring to the refrigerator that will be heavily oversized to minimize voltage drop and a watt/amp/hours totaling meter will put in the 12 volt line to monitor hours of operation and watts and amps consumed over time.

[MyronL]

Re: major surgery... will be watching with great interest.
PS: using tool pictured here best avoided

[hotfishtacos]

Originally Posted by MyronL

Re: major surgery... will be watching with great interest.
PS: using tool pictured here best avoided

I've got a carbide chain in mine for demo work....maybe for the old refer!...