Running Dometic on 120V vs 12V:

Help Support Van Living Forum:

PattySprinter

Well-known member
Joined
May 29, 2017
Messages
229
Reaction score
1
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 ...
 

galladanb

Well-known member
Joined
Dec 8, 2016
Messages
652
Reaction score
0
Location
Middle Tennessee
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?
 

PattySprinter

Well-known member
Joined
May 29, 2017
Messages
229
Reaction score
1
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 :)
 

jimindenver

Well-known member
Joined
Dec 20, 2014
Messages
5,266
Reaction score
38
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.
 

highdesertranger

R.I.P HDR
Joined
Apr 4, 2012
Messages
22,893
Reaction score
53
Jim got it. every time you convert there are loses. the more conversions the more loses. no conversion is 100% efficient. highdesertranger
 

DLTooley

Well-known member
Joined
Feb 20, 2017
Messages
1,378
Reaction score
9
Location
SW Colorado
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?
 

PattySprinter

Well-known member
Joined
May 29, 2017
Messages
229
Reaction score
1
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.
 

John61CT

Well-known member
Joined
Nov 22, 2016
Messages
8,057
Reaction score
5
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.
 

PattySprinter

Well-known member
Joined
May 29, 2017
Messages
229
Reaction score
1
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
 

John61CT

Well-known member
Joined
Nov 22, 2016
Messages
8,057
Reaction score
5
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
 

Weight

Well-known member
Joined
Feb 27, 2017
Messages
2,157
Reaction score
8
John. dont use your USB for that much wattage.
 

frater secessus

Well-known member
Joined
Aug 6, 2016
Messages
1,941
Reaction score
182
Location
desert southwest
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.
 

Latest posts

Top