Refrigerator on DC power

[lv2camp-FUN]

We went on a couple day trip and used our refrigerator. It was cold when we left. We put it on DC to travel a couple of hours and during that time the frig did not hold it's temperature. We plugged in to AC and the temp returned to a safe zone. We tried it again on DC and the same thing. Any idea's what is happening or what we are doing wrong?

 

[Mike-ClassB]

You're probably not doing anything wrong, the fridges in these things rarely
work very well on 12DC power. If you search Dometic fridge cooling, you'll see
you're not alone. You might try nudging the temp setting up a bit, as I've
found (on the rare occasion we've used ours on DC) it seems to help, and the
inside stays coolish, but never cold.

 

[visionquest-ClassB]

Ours works well on DC when driving. Maybe the 12volt element is isn't working correctly. Maybe till you get it figured out, you could use an inverter while driving. Not the most efficient way, but it might work well enough for temporary.

-Mike & Heidi
97 Roadtrek 170P "Taj Ma Trek"
HTTP://WWW.VanTramps.Com

 

[Mike-ClassB]

How do you run one of these things on an inverter while on the road?
I have a couple of small inverters, and might like to try it.
How do I get the fridge plugged in to one of them, or what's the wiring
work around?

 

[Mike-ClassB]

Rereading the Dometics 2310 manual cautions, it appears the 12V DC power may be cut off
when the engine is shut off, if the cut off relay is installed. It is supposed to prevent battery
drain, while the vehicle is shut off. Do you stop and shut off the engine for periods of time?
Might be cutting power to your fridge if you do.

visionquest: How do you run one of these things on an inverter while on the road?
I have a couple of small inverters, and might like to try it. How do I get the fridge plugged in
to one of them? I've never seen or looked for an AC cord/plug on the thing. I'm assuming there
is one that's long enough to pull out from under the galley counter somewhere, and will have to
dust off the old manual now, and see what's up. :wtf:
I would never have thought to try it.

 

[lv2camp-FUN]

Thanks everyone for your replies. We checked the fuse, it's good. Yes, we did stop and go often. I assumed the frig ran off the house battery and not the van battery, or am I wrong? Our last TT ran off the vehicle battery, but since we had a house battery I assumed it ran off that. We would turn on the house battery when we would be on the road, and just assumed that is what the frig worked off. We'll try cranking it up (or down) ....cooler..LOL..next trip to see if that makes a difference. We aren't sure how old the house battery is either, if it works off that, so it could be that the battery is failing. We are assuming it is 5-6 yrs old. We don't have much running off of it, and it doesn't seem to hold the charge for very long. I'll search the forum for more info on the frig. Thanks again.

 

[Ron J. Moore]

I have the 05 RT190P and we run on DC - not the coolest deal in town, but it does the trick. If we pull in to the Rest Area for a minute, I don't bother switching or turning off. I got rid of the original batteries and switched to AGM's (two 105 AH, 27 Series) a year after I bought the Trek new. We just returned from the FL Panhandle and we maintained temps that kept us from being concerned, and went to a/c when we pulled into a CG. Maybe it is the batteries that are the weak link...Safe travels.

 

[Mike-ClassB]

Sorry, the manual didn't say which battery it actually is wired to, but I'd say it's the house/coach
battery, so if it's weak, you might want to get it checked. Here's some rough figures for DIYers.

" On sealed-top batteries that do not have a built-in charge indicator, the state of charge can
be determined by checking the battery's base or open circuit voltage with a digital voltmeter or
multimeter. This is done by touching the meter leads to the positive and negative battery
terminals while the ignition key is off.

A reading of 12.66 volts indicates a fully charged battery;
12.45 volts is 75% charged,
12.24 volts is 50% charged,
and 12.06 volts is 25% charged. "

While driving the vehicle, and with the 12V DC power enabled (via the Battery Disconnect
Switch on the Monitor Panel being "on"), all batteries should be charging off the alternator,
so if the battery isn't being charged due to a physical problem (low electrolyte?), or just old age,
it could affect how much 12V power the fridge is getting. The manual says the fridge will
drain whichever battery is being used pretty quickly. If you stop the engine/alternator, you
temporarily lower the quality/quantity of the power to the fridge, so that may be a factor, too.