48V Mini Fridge Replacement

[agenthex]

My mini fridge is dead. Accidentally damaged the coolant loop, and it's probably not worth repairing.

Now, I'm looking for advice.

It seems that my choices are between an inexpensive replacement, marginally more efficient than my dead fridge but still AC powered, and a significantly more efficient DC fridge but at an equally significant cost.

I have a 48V battery bank, a 1KW pure sine inverter, and a 120W DC-DC converter for 12V output. If my fridge is DC, I will not have to run the inverter and could eliminate that inefficiency, but I'm not sure what to get.

I use maybe 20W on the DC converter for a small fan and phone charger, so it might be able to handle the persistent load (though not the startup, which could be AC until it's cold).

The dead shell of a fridge is still intact, so maybe there is a solution involving converting it to a DC compressor or something. Probably not feasible, but worth asking if anyone knows enough to advise.

Thoughts and recommendations are welcome. Price is a factor, but I will hear any advice.

Thanks.

[Mike90250]

I'd say having a pro come, pump down and recharge the system, is worth it, since I don't know of ANY 48V fridges. I'd guess and hour of labor, and $20 for coolant and lube.

[Sunking]

I don't know of ANY 48V fridges.

Well now you do, Sun Frost.

[mapmaker]

Well now you do, Sun Frost.

Do they use a 48-->24 volt DC converter? I thought they use the same Danfoss compressor used by Sundanzer and Stecca, which self-configures to work on 12 or 24 volts.

Their site says "48 volt DC: Please call for pricing." [bold emphasis is theirs, not mine]

--mapmaker

[agenthex]

I am leaning toward this unit:

Whynter FM-85G 85-Quart Portable Refrigerator/Freezer, Platinum https://www.amazon.com/dp/B002W8GV8S..._6G-8tb0P8FCXB

It looks like it would work on my 12V converter, and chest style would reduce cold air loss from opening.

Reviews are pretty good, it can be fridge or freezer, and it doesn't completely destroy the bank like some $1K and up options.

Thoughts and input welcome. Thanks.

[agenthex]

Whynter FM-85G 85-Quart Portable Refrigerator/Freezer, Platinum

Follow up: I bought this fridge about a month ago, and I really like it. I had a small issue with one of the handles, but I was able to fix it.

This fridge uses less power than my last fridge (AC vs. AC). This was not unexpected. While connected to AC, the internal fan will always run.

On DC power, this fridge is even better. The spec says it uses <100W max, so I put mine on a buck converter that can deliver 10A@12V, and I haven't touched the big inverter in a week.

The documentation says this unit will run on 24V and has a built-in low voltage cutoff for battery operation (both 12V and 24V, auto-sensing).

I set mine for 38-deg F, and it kicks on at 40. Minor issues aside, this is a wonderful refrigerator. I snagged mine for $560+tax, so minor issues included I couldn't be happier.

[inetdog]

What is the space inside like? Can you use it as a refrigerator with freezer compartment or is it a uniform temperature inside?
The constantly running internal fan sounds like a good option to have for quickly chilling warm food that is added.

[agenthex]

The constantly running internal fan sounds like a good option to have for quickly chilling warm food that is added.

Sorry, I described that poorly. The fan is in the compressor section, not in the food compartment.

There is no partition for dual fridge/freezer, but there is a shallow end created by the space the compressor section takes up below, so it may be possible to set it for below freezing and make a horizontal partition to effectively make it dual, freezing stuff in the deeper end. The difficulty is that getting stuff out of the bottom can be tricky if you stack on top for space.

Also, I don't know for sure that you could use it for both, but at some point I will try and report back.

[jony101]

the whynter look exactly like the edgestar I had, including the grey color, I had the 43 quart which was plenty large for my needs. Its built like a tank and was extremely reliable for when I had it in my van, no matter what the interior temperature in my van it always maintain the proper cooling effect.

The danfoss compressor is very good in the use of power. Even though the exterior of the fridge use to get hot when it was running it never comsumed more than 30 amps in a 24 hour period when set to 40 degrees. As far as amp usage, it peaked at 6 amps when the compressor first started than ran at about 4 amps, I measured this with a dc wattmeter. I had mine connected directly to the 12 volt battery.

The downside for these fridges is they comsume too much power if you want to use them as a freezer. You need a large battery or 2 large batteries. I had a 75 ah battery and tried using it as a freezer and didnt make it through the night. On freezer setting the compressor was running constantly. This is mainly from the thinner insulation used on these models more appropriate for fridge use. It is capable of freezing temperatures but the power required is much higher.