Sears mini fridge/freezer thoughts

[VanLifeCrisis]

Well ive had it for a little over a week and wanted to give my initial thoughts.

Im referring to this mini fridge:
http://www.sears.com/kenmore-3.1-cu...p-04695693000P?prdNo=1&blockNo=1&blockType=G1

I purchased a cobra 800 inverter, and it handled it fine. It does chirp the alarm for a split second when the compressor kicks on sometimes, but doesnt full on alarm.

First thing i want to emphasize is that this fridge is bigger than i expected. True i had dimensions but i didnt really grasp it until it was in the van and eating up all my room. I ended up tearing out my bulkhead door and putting it there, so now i got most of it between the front seats. Not ideal but it gives me more room.

I had an initial battery charge probably somewhere aroiu d 80% when i turned it on first time. I was a bit alarmed at how low my volt monitor descended when i switched on, i never had such a load on them before. Of course it went back up after the compressor kicked off.

The first time i ran it lasted about 2 days until i felt it needed to be charged (around 50% battery when compressor is off). I charged batteries to 100% this time, and it has lasted 3 days so far this time and i estimate i have another day maybe 2 before it needs recharged. This might be different when it isnt in the 20s or lower out tho.

Food is all cold, sodas, chicken, frozen veggies and even ice cream.

Overall i am pleased so far for the amount of money put in. I think it will really pay off once solar is hooked up. I will report back after some time on the longevity issues of using a home appliance, im sure it will get smacked around this spring.

---

If i were to do it again i might hook up to shore power to get it primed before putting it in the van, that way i avoid that initial strain on batteries.

 

[SternWake]

Thanks for the report.

How much battery capacity do you have?

How often does the compressor kick on, and for how long?(duty cycle.) What have the internal ambient temperatures of the van been during your observations?

Are you keeping tabs on internal temperature of the fridge?

Fatter cabling between battery and inverter might eliminate the chirp on startup.

It is noisy when the compressor kicks on?

 

[VanLifeCrisis]

I have 220amp hours, so 100 usable about.

I set the fridge on the 'cold' setting, there is a colder and coldest settings as markers on knob, you can have it in between. Setting it below 'cold' causes the compressor to kick on every few minutes. Not counting the initial cooling down of the fridge, it kicks on maybe once an hour. Very infrequent. In fact i havent heard the inverter since i got in the van a couple hours ago, but its pretty cold in the cab.

Temperature is wierd, as i am out of the van eight hours a day, so temp in van is outside, usually 20-30f, when imin the van cargo are is around 60, but most of the fridge is in the driving area which is cold enough to freeze conensation on window so below 32.

I do not monitor the internal temps, but all the food and drinks are cold as any fridge, and freezer keeps everything frozen so far. Sorry im not more scientific

The fridge is silent even with compressor running. The inverter isnt, as the fan fires up when compressor runs. It isnt intolerable tho in fact its not as annoying as my cobra 400 when running my laptop.

---

Sorry for typos, posting from android

 

[SternWake]

Thanks for the info.

I Wish you had some more tools for measuring the current it is using during compressor operation, and what your inverter is using when not actually powering the compressor. But we all can't be battery nerds

I assume you are just using Voltage to determine a 50% point? Do note that this is unreliable while the battery is still under loads, especially cycling ones as the battery voltage will rebound for hours after all loads are removed. It is hard to really nail down a 50% mark while still under load with voltage. It will vary greatly with battery capacity, brand, age, health, temperature, and the amount of load. General ballpark is best one can really hope for without more measuring tools.

Also that cold batteries have less overall capacity than warmer batteries.

If your fridge is actually using 100 amp hours in 2 days, in very cold ambient temps, that is a lot. That is like 4 to 6 times the amount my danfoss powered 1.8 cubic foot fridge uses in 50 to 60 degree ambient temps.

3.1 cubic feet interior space is pretty large, especially for one person, and in a van as well. We can't really compare the electrical usage of a 1.8 vs a 3.1 cubic foot fridge.

Does the fridge have an exposed condenser on the back, or in the compresor compartment? This will look like cooling fins or a car radiator.

Glad to hear it is very quiet. That is a huge deal for me.

I hope it performs well when ambient temperatures increase, and that your battery capacity is enough.

Like it or not, you will be a test bed for doing the residential fridge on an inverter. Your fridge is advertised to be very low electrical consumption so it is pretty much a best case residential fridge powered by inverter and batteries scenario in actual use and will help people decide whether this initial lesser expenditure ( vs a 5$$.$$ 12v fridge)pays off in the long run.

If you are able to post pics showing the actual size of the fridge in your van, it would be helpful for others to realize how big the fridge actually is.

 

[WheelEstate USA]

Good info. Hope for more reports as the weather changes.

 

[VanLifeCrisis]

Hmm...not sure, maybe i could go longer on my batteries but im a scaredy cat lol i figure if its 50% without a lot of rest it'll be a safe stopping point. Im not sure how else to tell when to charge without risking my battery and without shutting the fridge down for long periods.

How long should i excpect 30 watt fridge last on 100amp hours in between charges?

Hmm...i will take a vid of the fridge maybe..low light conditions tho...

---

Ok, here are some pictures. Interesting note, i didnt realize but since i ripped out the door to bulhead, ive been heating the front too...so ambient temps are higher than i thought.

Perpective

Temp cab (55 before i opened door for more light)

Temp cargo(this was 78 before i opened door)

Back

 

[VanLifeCrisis]

Oh come on you gotta be kidding me, none of those images worked?! And i cant edit cause it added posts. Oh well.

---

Let me retry

Ok, here are some pictures. Interesting note, i didnt realize but since i ripped out the door to bulhead, ive been heating the front too...so ambient temps are higher than i thought.

Perpective

Temp cab (55 before i opened door for more light)

Temp cargo(this was 78 before i opened door)

Back

---

Sorry, once on a real freaking computer i will shrink those...this crap is frustrating on a tablet

---

Does the length of cord from inverter to fridge make a difference? Im using a long extension cord cause its all i had on hand. The wires from battery to inverter are short.

 

[SternWake]

Thanks for getting the pics up. A couple (CTRL - clicks) made the photos viewable.

That is a big fridge. I personally could not use that much space unless i was trying to.

Couple deductions I'd like confirmed here. The temps showed are ambient inside and ambient outside temps, not the interior temps inside the fridge right?

Can you move one of the sensors to the interior of the fridge? temporarily?

i bring this up cause refrigerations goal is to keep food under 40 or 41F. It takes a lot more juice to keep food at 31 vs 41

I like the voltmeter. Where is the voltage sense wire pulling voltage from? Best(for accuracy) is if it is right on the battery (+), worst, is if it is the same connection that the inverter is pulling current from. It will read lower than right on the battery terminal

The length of thickness of 120vac wiring from inverter to fridge is of much much less consequence as 12vdc wiring from battery to inverter. The quality of those connections is very important too. Stranded wire twisted and bent around a terminal and crushed under a finger nut should be considered temporary at best.

 

[VanLifeCrisis]

I cAn but setting the fridge lower than i have it makes it kick on and off constantly, so not much point. The freezer doesnt have a setting, iguess its auto based on fridge setting or set temp all the time. I noticed ice cream gets soft in door, but not in side...might be because i had it near 80 in here lol

The voltmeter is cheap crap to be honest, but it works..i have everything wired to battery with proper terminals tho inverter uses clamps it came with.

---

The fridge is at 36 the freezer is at 31 (might explain the ice cream in the door being soft).

 

[WheelEstate USA]

I read somewhere that ice cream needs to be in something like zero degrees to stay solid.
The back of the fridge is the best place.

 

[Lucky mike]

all refrigerator/Freezer combo's set there temperature according to the refrigerator compartment which is normally 36 to 40 degrees......if the outside ambient room air temp is close to this the compressor will shut off because it thinks it has run enough ......if you google short Refrigeration cycles....it will explain it.

if your freezer is above zero this is the reason......the only way to independently split domestic refrigeration into 2 systems is to run 2 compressors or a split solenoid system......both are not cost effective in the mfg. eyes......nor would a customer pay for it.

 

[VanLifeCrisis]

Hmmm..i moved the ice cream to the back. I think this needs more testing. Yes...definitely *nom nom* delicious science..

---

Today is day 4 and when compressor is not running im at 12.24 volts...should i charge or keep going. I usually never let it go below 12.2 (usually charge at like 12.4 cause i can).

 

[GotSmart]

I have been thinking about this fridge. I guess it has gone up in my "must have" list. Thanks for the report!

 

[VanLifeCrisis]

Well, it might have last longer but to be safe, I decided to charge it. It lasted 4 days. From what I gather from an above poster the 12v kind can last like 10-12 days before recharging (on 100 amp/hours). This fridge however is larger, which can be a pro or a con. Personally i would prefer a smaller model. I guess like most things you have to decide if it fits your situation. Since i can supply juice at least every 4 days, it works for me. Even better when i put up my solar (if its cloudy for a week i can still plug up). Im thinking you could genny charge if you have to top off and are boondocking.

Not bad for 1/3 the price of a 12v unit.

The longevity might be an issue so ill report more on that probably with more useful info in the spring when i plan to travel, hit up some parks, and Appalachian backroads etc.

 

[VanLifeCrisis]

One last shot i forgot of the inside.

 

[akrvbob]

I suspect it's premature to think it's going to work better than 12 volt compressor fridges. Let's wait and see how it works when the temperatures in the 80s and 90s. Any fridge should work great with the temperatures in the 30s-50s!!
Bob

 

[SternWake]

Yeah, temps in the 80's and 90's are a whole different story. While I have measured very low consumption with my 12v unit at lower temps in the 50's and 60's, I also have the benefit of extra insulation, and a smaller space in which to keep cool, and a very efficient method where my condenser transfers collected heat to the ambient air forced through the condenser with the condenser fan .



If there is no obvious condenser on this Sears model, well it will have somewhere where it transfers the accumulated heat. The condenser can be in the fridge walls near the compressor. As the temps rise this less efficient transfer off heat from the compressor greatly increases the work the compressor (AND BATTERIES) has to do to maintain sub 40f interior temps. A small 12v muffin/computer fan aimed at the "hot wall" will help greatly in higher temps, something in the 12 to 30 cfm range is plenty and will only add a very modest electrical load which should be negated by smaller duty cycle.

If one builds a cabinet to house this fridge, or any fridge, then the area of the condenser NEEDS adequate airflow for the fridge to perform at its minimum electrical consumption for the given ambient temps and heat load inside the fridge which must be removed.

If one does not have a large battery bank or the ability to plug in every so often to fully recharge, they should consider the extra outlay for a dedicated 12v unit as a priority.

Dazar, I think you can go longer than you are going. 12.24v under load with 220 amp hour capacity is still over 50%, and perhaps as high as 65%.

Not going to hurt by recharging early, and it will probably chirp the inverter alarm less on start up recharging early.

My small 1.8 cubic foot 12v fridge could perhaps fit some ice cream sandwiches in the freezer compartment but traditional tubs would never fit.

 

[GrayWhale]

This guy is using a regular, home fridge for over 2 years now I think and without any problems.

I guess if you go offroad or on dirt roads a lot, it could be a problem. Maybe cushion and twist tie all the connections and compressor parts as best as possible in the back. Thick rubber and stuff should absorb a lot of the impact.

 

[VanLifeCrisis]

Just want to note i misjudged the temps i was keeping my van at...it was 55 front and 78 back so it was used in fairly warm temps....maybe not desert in the sun hot but not as cold as i thought.

There was also that older woman on youtube who had used one for years as well, she used a genny every few days to charge up...if i find a link ill post back.

If i had the cash id prefer the 12 but with all the other stuff i need like new tires, i will go less ideal for cost savings.

 

[VanLifeCrisis]

Update: with the warmer weather and use of a timer, i can get 2 maybe 3 days (no sun) before i have to recharge. I'm thinking insulation may help.

If you have a way to recharge or get a lot of solar it would wprk fine, otherwise might save for a smaller dc unit.