Running Dometic on 120V vs 12V:

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PattySprinter

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Running Dometic on 120V DC vs 12V AC ... Dyers was wonderful in getting Dometic to replace the broken CC40 cooler that was sent to me.
The second cooler seems to run fine - and for $335 delivered - it is half the price of the Dometic I was eyeballing. Thanks to everyone who posted about this cooler.

I ran it for a couple days on 120V and about 5 times an hour it kicked on for about 2 minutes - surging to 80-ish watt output for a few seconds and then going down until it shut off.
At this rate it drained my Goal Zero 1000 (with 200W solar) down to 75% each night ... and the solar quickly charged it back up the next morning.

Today I switched out the plug to 12V DC and when the Dometic kicked on for its 2 minute cycle - the watt output only surged to high 30's and then went town until it shut off. I haven't noticed yet how many times it cycles on per hour with 12V yet.

What a difference!! For those that own Dometic coolers - is your experience similar? I am just learning ... long way to go ...
 
I have an Engle, and it is supposed to know when there is 110v or not. And if not it runs on 12v.

In my case it's either or. Which I like! And it runs as long as there is some flavor of power available. I like that I don't have to manually switch it one way or the other...

As far as power consumption on one source or the other, I guess it seems the same. I never thought to see if it was different per source.

And I assume that is what your asking?
 
galladanb said:
As far as power consumption on one source or the other, I guess it seems the same. I never thought to see if it was different per source.

And I assume that is what your asking?

I have no reference if this cooler is behaving as it was meant to - looking for any (hive-mind) input.
Thank you for replying :)
 
On 120Vac you have a inverter not just to power while the fridge runs but in stand by when it is off. Then the fridge has to convert the 120Vac down to 12v DC and that converter is on even if the fridge is not actively running. So you are converting 12v to 120Vac and then converting the 120Vac back down to 12v plus the losses while not running.

One thing to consider is if the battery drains down each night but is easy to recharge quickly that it may have capacity loss.
 
Jim got it. every time you convert there are loses. the more conversions the more loses. no conversion is 100% efficient. highdesertranger
 
I just performed a 'kill a watt' test on my cc40 and saw similar numbers. I was educated through same that dc and ac amps are not exactly the same. I still don't understand volt amps, etc. I did see similar numbers.

What are you using to measure dc amps?
 
DLTooley said:
I just performed a 'kill a watt' test on my cc40 and saw similar numbers. I was educated through same that dc and ac amps are not exactly the same. I still don't understand volt amps, etc. I did see similar numbers.

What are you using to measure dc amps?

DLTooly - I have the cc40 plugged into a goal zero 1000 that is powered by 200w solar. The gz displays all the usage and input.
I am so amazed and relieved to see how little it uses on DC - sweet isn't it?

... when I get my van I am not sure how I will hook up the Maxx fan bc I think it goes to dc also and the goal zero has only one dc outlet.
 
You should set up vehicle's house circuit so the powerpak plugs in directly with a high-amp Anderson plug.

Do not use the ciggie port for this, limited to low amps and unreliable connection, wouldn't use it for the fridge either long term, especially in a vehicle.
 
John61CT said:
V x A = watts

not a DC vs AC issue

I have memorized W = V x A ... but I need to sit down really absorb how to apply it.

... I think it reminds me too much of algebra so I have been avoiding it  :s
 
Watts is power, independent of voltage.

1000w device, battery, USB, shore power no change.

But 115V shore say 9A

12V DC it's 80A

USB 5V it's 200A
 
John. dont use your USB for that much wattage.
 
galladanb said:
I have an Engle, and it is supposed to know when there is 110v or not. And if not it runs on 12v.
...
As far as power consumption on one source or the other, I guess it seems the same. I never thought to see if it was different per source.

Did it seem to be any colder on 110vac vs 12vdc?  I seem to recall the old 3-way fridges did better on some sources than on others.
 

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