Starting 12V Absorbtion Fridge on Battery

[RoadTurtle]

For grins, I started it on 12v... it hit the battery bank much harder than I expected. It was an experiment, and took about 20sih hours to finally cook down, and hit my 600ah battery bank for almost 500 amps. It was an empty fridge. I so need to either upgrade this fridge to 12v compressor, or replace it with a 12v compressor fridge.

 

[sunshine_eggo]

Yep.

FWIW, it hits no harder than 120VAC. They tend to run around 350W. ~3A at 120V or ~30A at 12V.

A ~7.6cu-ft absorption fridge uses nearly ~5kwh/day when maintaining with typical use.

I've recently enjoyed the failure of my double-door Norcold, so I am currently without fridge of any kind. A nice residential one that fits the hole is $1500... vs. a new cooing unit at $800. I thought it would be a no brainer, but I'm not so sure now. I have the battery/PV with only half of both deployed. Hard to know if the next owner would prefer compressor or absorption.

 

[Rednecktek]

Hard to know if the next owner would prefer compressor or absorption.

It always seemed to me from my experiences with both that while a compressor needs more power, it needs it for FAR less time over the day which says it's a net benefit to go compressor over absorbtion.

Ymmv though.

 

[sunshine_eggo]

It always seemed to me from my experiences with both that while a compressor needs more power, it needs it for FAR less time over the day which says it's a net benefit to go compressor over absorbtion.

Ymmv though.

Nope. No mileage variation. Same-size absorption fridge will use about 5X the energy of a modern compressor fridge. Compressors tend to use marginally more power, and they DEFINITELY run far less than the heating element in an absorption fridge.

 

[wme]

The typical absorption fridge is designed so that 12v will just maintain temp, it's not really designed to cool.
Put frozen stuff in the freezer, cold stuff in fridge. Then rerun the power consumption over a couple of days.
Even on 120v AC it takes a long time to cool an empty fridge. If the unit has a propane setting it will run for weeks on a 20lb cylinder.

 

[Aussieguy]

No need to upgrade..
connect shore power while at home/storage to get things cold before your trip
or use the propane......... even while driving !

I store mine at home and use a 120v contractor grade power cord + adapter .......... to connect to a 20amp outlet in my garage
I can run the air conditioner , fridge and converter while loading / preparing the trailer for a trip.
pre-chill any largish items in the house fridge

look at supplementing with a small 12v chest freezer?

PS.. I now have 12v fridge .....and have to get more battery capacity
it drains the existing crappy battery overnight unless on shorepower.

 

[SamDeleted]

~5kwh/day

That is expensive for a fridge!

My big home 240vac fridge uses less than 1kwh a day

 

[sunshine_eggo]

That is expensive for a fridge!

My big home 240vac fridge uses less than 1kwh a day

Your fridge uses a compressor for the refrigeration cycle. RV fridges use fire or electric heating element for the ammonia-water absorption cycle. It takes about 5X more energy to make heat with a source than it does to move heat with a compressor refrigeration cycle.

Your fridge can't run on propane. RVs carry around between 135 and 202kWh in a single bottle with many having two bottles.

 

[Johneb]

I went with the 12v compressor replacement on our norcold 1210. I am thinking of replacing it with a residential. More room for food and works better in cold climate.

 

[SamDeleted]

Your fridge uses a compressor for the refrigeration cycle. RV fridges use fire or electric heating element for the ammonia-water absorption cycle. It takes about 5X more energy to make heat with a source than it does to move heat with a compressor refrigeration cycle.

Your fridge can't run on propane. RVs carry around between 135 and 202kWh in a single bottle with many having two bottles.

Yes we've been camping for years I knew the 3 way fridges were bad on 12v , I didn't realise quite how bad !

 

[RoadTurtle]

It was an experiment. We were getting ready for an upcoming trip, and wanted to see how bad startup would be only on electric. It was worse than I expected. Next time I do that, I'll start it in the morning instead of the afternoon. Variable expense on solar is still less expensive than propane

 

[RoadTurtle]

I went with the 12v compressor replacement on our norcold 1210. I am thinking of replacing it with a residential. More room for food and works better in cold climate.

If my fridge fails, that will be on my list... however, since I said that, the fridge will never fail!

 

[RoadTurtle]

Norcold has ended production of propane fridge...

 

[wme]

In the USA, production has been shifted to "other locations"

 

[Sojourner1]

For grins, I started it on 12v... it hit the battery bank much harder than I expected. It was an experiment, and took about 20sih hours to finally cook down, and hit my 600ah battery bank for almost 500 amps. It was an empty fridge. I so need to either upgrade this fridge to 12v compressor, or replace it with a 12v compressor fridge.

Do you mean you were using an inverter and running with AC. What fridge?

 

[wme]

A typical absorption RV fridge runs off heat. The standard ones are 2 way and get the heat from propane OR 120v AC. The higher end ones are 3 way and add a 12v DC heat coil. The 12v coil produces less BTUs than propane or the 120v coil. So it's handy for maintaining the temp when traveling if running propane under way bothers you.
My grandfather had an absorption fridge that ran off kerosene/heating oil, it was over 40 years old when it expired.

 

[Checkthisout]

That is nice and smart to run the absorption fridge off an inverter while driving.

I've always been curious how many re-lights a propane fridge undergoes when driving at 60 mph.

Everyone uses them while driving

 

[SamDeleted]

That is nice and smart to run the absorption fridge off an inverter while driving.

I've always been curious how many re-lights a propane fridge undergoes when driving at 60 mph.

Everyone uses them while driving

I've never run them on propane while driving, too much risk of the pilot light going out to me

 

[littleharbor2]

I've never run them on propane while driving, too much risk of the pilot light going out to me

I was concerned about that too but found, (at east with my fridge), this wasn't a problem.

 

[GravelRider]

Wow, I'll never complaint about my 12 V compressor fridge again! lol