12v refrigerator/freezer AH per 24 hours?

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Todd & Meg

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I am sizing the battery for my teardrop camper. I want to size for a future refrigerator freezer combo. I have read they draw from 2 to 4 amps while running, Start up is more like 5 to 10 amps. Snowmaster is the only manufacture that listed a typical run time at 12 hours out of 24. That model draws 2.5 amps so that would total 30 Amp Hours in 24 hours. That is a fair amount of power in a day.

Has anyone done a real world test to come up with real daily use data?


thanks

Todd
 
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trailhunter

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I am sizing the battery for my teardrop camper. I want to size for a future refrigerator freezer combo. I have read they draw from 2 to 4 amps while running, Start up is more like 5 to 10 amps. Snowmaster is the only manufacture that listed a typical run time at 12 hours out of 24. That model draws 2.5 amps so that would total 30 Amp Hours in 24 hours. That is a fair amount of power in a day. x

Has anyone done a real world test to come up with real daily use data?


thanks

Todd
Depends on climate and insulation of the fridge, I've seen mine draw less than an amp as the fridge rides the wave on a cold day. On hotter days. Its cranking 3-5 amps. I suggest you incorporate solar power as well as a deep cycle battery
 
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Todd & Meg

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After much searching on the web I found this chart. Very useful because it breaks it down in by seasons. Summer temp was around 90 degrees, winter was around 30. Interior temp was 23 degrees F.



I'm going to have to rethink the fridge. A 100 watt panel puts out about 30 amp hours in a good sunny day. So would need at least 200 watts of panel. Not sure I have room for that.

Todd
 
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Mark D

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How often do you move camp? I just bought a Wynter 90q, I placed it in the back of my rig and hooked it up to a group31 battery. I know it is not a real world test, the fridge was empty and I didn’t open it during the test. It ran from Friday at 6pm til I finally ended the test Tuesday at 6pm (4 days). I started with a fully charged battery (13.1 volts), fridge set 38* main compartment 31* small compartment. When I stopped the test my battery was at 12 volts (about 50%). Since we never stay in one spot for more than 3 days I figured I would be fine with the vehicle charging the aux battery while we move.
 

[DO]Ron

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toxicity_27

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Thone numbers seem a bit inflated to me. While I don't have specific numbers I have ran my Engel MT45 off my second battery for 3 days without moving or having an issue..

How long are you planning on not charging the battery? What else are you going to run off it?
 

Steve

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Yea, those numbers seem pretty high. Here's testing done on my National Luna 90 Twin:

Both bins set to 39°F. Both bins empty.
70°F ambient for 12 Hours
90°F ambient for 7 hours
109°F ambient for 5 hours

Total consumption for 24 hours: 27.7 Ah

Ref link: https://goo.gl/iN2thH
 

Tim

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Maybe it’s just talk but I’ve always been given the impression that a smaller fridge is less efficient and would use more in a 24hr period. We are running a smaller fridge and it does seem to consume more but it also gets opened for longer periods because it’s usually stacked full and you have to half empty it to get stuff out.
 

Todd & Meg

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Thanks for the info so far.

I am building a teardrop camper and am sizing the battery. I want to go smaller because it’s less weight on the tongue. My typical amp hour use is 15 AH. That is for a typical camping day 70-80 degrees days with mid 30’s to 40’s at night, charging phones and iPads for a few hours a day. Just like fridges AH useage will vary with the seasons, summer with longer days will need to run the lights less. The fan on the heater will run longer in the winter. If we need to really conserve we can probably get away with 5-6 AHs. I am going to have a CTEK dc-dc charger so I’ll mostly charge from the TV. It also has a solar controller built in if I want to go that way.

Since we are new to camping in a teardrop we are not sure what are typical trip will be. We came from camping off an adventure motorcycle so never stayed in the same place for two or more nights. I think weekend trips will be more base camping, and longer trips will be on the move.

@Mark D, I did see that artical a while back and thanks for reposting it. There is some useful info there.

@Tim, you make some good points about the smaller fridge and looking for stuff with the lid open. The other thing a test with an empty fridge is pretty much useless. A refrigerator with out thermal mass is very inefficient. You need to fill the refrigerator with at least water bottles to hold the cold. That Goes for all refrigerators.

Todd
 
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