Anyone Running a Dometic Fridge? 12 or 24v?

[KamikazeKunze]

I hope I was clear in my post that my "running" measurements were the fridge running, I never started the truck at all.

That said Id be curious to see what the voltage was if you spike in to the cord near the fridge. It should stay above 24v at that point (truck off fridge on) and then unplug it, cobble up a short ground (top prong, I just used a bent spade connector) and use your DVM to connect between the bottom prong and cord and get a read on amps.

And since your problem is when the truck is not running all your tests should be truck not running as well.

Yes sir. I have the stock power in the box. And 10’ of super thick high quality jumper cables to where I’m getting power for the fridge. My temp test cable sucks. And will use another set of cables for the test. Ultimately if I wire things up properly and hack the factory power cable for the plug I’ll have an additional 4-5’ of cable added Using a much better gauge creating a better “last leg” of the connection.

sounds good. At this point when the fridge does kick off the truck always starts and the volts rebound accordingly.

 

[richingalveston]

you should have a higher voltage than 27 volts. check to make sure your alts are healthy and that one of your batteries does not have a dead cell. have them load tested.
Running solid wire will pass less amps than stranded wire. Electricity runs on the surface of the copper. Stranded wire has a lot more surface area than solid of the same gauge. If it were me, I would.
1. change the wire to stranded and the largest gauge reasonable for the load and distance. Extend that wire all the way to the load with out splices or junctions.
2. load test the batteries and figure out why the alts running with no load are not close to 28 amps.

 

[KamikazeKunze]

you should have a higher voltage than 27 volts. check to make sure your alts are healthy and that one of your batteries does not have a dead cell. have them load tested.
Running solid wire will pass less amps than stranded wire. Electricity runs on the surface of the copper. Stranded wire has a lot more surface area than solid of the same gauge. If it were me, I would.
1. change the wire to stranded and the largest gauge reasonable for the load and distance. Extend that wire all the way to the load with out splices or junctions.
2. load test the batteries and figure out why the alts running with no load are not close to 28 amps.

I would have thought so seeing as it’s a 28v alternator. I have both but swapped them out recently cuz the one that was in it only was pushing 26.5 volts the other one was 27.2v so I went with it. The prior owner didn’t like the double alternator setup. And has turned it into a single, and oddly enough running a massive 24v to 12v convertor to run the 12v systems.
‘Side note to that, my 24v 3000w inverter hates getting anything input over 27v volts. It starts crying and flashing.
I’d love to run both alternators again but need the brackets and possible them rebuilt.

 

[cruzer747]

Hope you made some progress....

just thought I would add that while my m1010 already was 12v only I would be hesitant to say that running at 27v is a bad thing. That is 13.5v/battery. I watch the charge on both my m1010 now and my 6.5l 91 sierra and both of them will vary the voltage depending on state of charge. Honestly there is something a little fishy with the Leece Nevile in my m1010 but both will start around 14.2 or so if there needs to be any charging done.... then my sierra will see about 14.6 and the m1010 will push slightly harder than that (with occasional blips to 15v! The lights at night will noticeably surge not to happy about that ) but then when the batteries are mostly full the voltage eases down on both of them to about 13.4-13.6 (right around 27v if it were doubled).

I would be interested to know a little more about how an alternator manages t voltage at different states of charge but I have a bit much on my plate at the moment.

 

[dmetalmiki]

I don't see why your unit will not work.
Having checked everything else, Have you checked the output of the inverter?.
We have a 'Dometic', And a full size household fridge freezer in my Camper..and both work just fine.
The inverter is 7000 w. continuous capability. (Off 8, 100AH batteries.)
But, the Dometic on battery power does Not 'Compress' anything.
Seems it has a heater element for the "Low voltage" range. 24Volt.
Perhaps our unit is a different model though. (Bought in the E.U. Germany.)
Just a thought,, The cabeling to the set up is somewhat 'Massive', I used welding cables. !.

 

[KamikazeKunze]

I don't see why your unit will not work.
Having checked everything else, Have you checked the output of the inverter?.
We have a 'Dometic', And a full size household fridge freezer in my Camper..and both work just fine.
The inverter is 7000 w. continuous capability. (Off 8, 100AH batteries.)
But, the Dometic on battery power does Not 'Compress' anything.
Seems it has a heater element for the "Low voltage" range. 24Volt.
Perhaps our unit is a different model though. (Bought in the E.U. Germany.)
Just a thought,, The cabeling to the set up is somewhat 'Massive', I used welding cables. !.

Not using an inverter for the fridge other than to test stuff. It’s mainly for the induct cooktop and such.
i definitely hear the compressor kick on when it needs to cool one or both compartments.

 

[cruzer747]

any updates? I would say one last thing you could do is just put the fridge right next to the starting batteries and hook it up with the factory lead and see how it runs. Keep a voltmeter on the actual battery (do not care what the fridge says) and if the battery voltage drops below 12v (or even 12.2) while fridge is running then your batteries are tired. This is assuming they are fully charged.

Hopefully you already got this all sorted.

 

[KamikazeKunze]

Not really, it’s been very cold here and I haven’t wanted to work outside. I did return the fridge. I’ going to rework my wiring a smidge this weekend. Step up the gauge and shorten a few runs, adding two house batterie. I am also ordering the ICECO fridge which uses the Danfoss compressor.Will keep you posted.