I have a 2015 Jayco Pinnacle with a residential fridge. When I am plugged in to shore power and have fully charged batteries (two of the biggest Trojan 6 volts that I could fit in the battery cases) my voltage readout is 13.2/ 13.3. After driving for 4 to 5 hours my readout has dropped to around 12.3 to 12.4 volts. I thought that it should at least maintain my full charge running off my truck charging system. When we then dry camp overnight my LOW voltage alarm starts to beep usually around 5 am and of course wakes me up. I did not spend 100K to have a very fancy alarm clock. Any suggestions would be appreciated. Thanks .

Sounds to me like too much draw and not a big enough reserve for dry camping and towing. Depending on the draw (residential fridge) don't expect your trucks stock charging system to keep up.

Read voltage at the truck battery and then at the RV battery when this occurs. Very likely that the wire gauge is too small to allow full voltage/amperage to reach the RV battery.Unless you are running a lot of heavy electrical loads in your truck, your alternator should be able to keep up with an inverter powering a residential refrigerator.

need to know amp hour ratings of batteries or the model number so we can look it up on the charts.draw of fridge and duty cycle. Are you expecting fridge to cool from ambient temp down to proper temp or are you precooling fridge on shore power?Do not make the mistake of thinking that FOR EXAMPLE 2 six volt 250 AH batteries means you have 500 AH at 12 volts.you have 250 AH at 12 volts.So get the figures and repost here

The 'charge line' from truck to 5vr via 7 pin connection is NOT large enough to recharge those batteries and keep up with the demand.The OEM charge line is barely large enough gauge wire to maintain battery.You need to run a larger gauge wire on truck to 7 pin to use for charge line

bc canuck wrote:I have a 2015 Jayco Pinnacle with a residential fridge. When I am plugged in to shore power and have fully charged batteries (two of the biggest Trojan 6 volts that I could fit in the battery cases) my voltage readout is 13.2/ 13.3. After driving for 4 to 5 hours my readout has dropped to around 12.3 to 12.4 volts. I thought that it should at least maintain my full charge running off my truck charging system. When we then dry camp overnight my LOW voltage alarm starts to beep usually around 5 am and of course wakes me up. I did not spend 100K to have a very fancy alarm clock. Any suggestions would be appreciated. Thanks .I would check the 12V current being drawn. It sounds like you are drawing more current than the truck can put supply. With a long 12V wire from the front of the truck back to the RV, you will be lucky to supply 8 amps. You could be drawing more than that if running the refrig on 12V. Sometimes the 12V wire isn't even connected in the truck or RV, even though the pin is in the connector. Might check that.The only other thing I can think of is installing a much heavier gauge 12V wire in both the truck and RV. Even if it's a 12 gauge, it may not supply enough current for your situation.

Battery voltage drops!!! | Good Sam Community

MEXICOWANDERER
Explorer
Oct 23, 2015
If I run into something like that now, I smile and start back peddling...

"Lo siento no hablo ingles"

"I'm sorry but I don't speak spanish"

"I'm deaf"

"Soy sordo"

"I'm disabled"

Tengo incapacidad"

The ill-tempered who snap at the hand holding a treat. It's really true "You Can't Cure Stupid".
But note the conversation has drifted and none of this has anything to do with the OP.

What it DOES have to do with is learning about what you're trying to do. I am computer and arduino ignorant and will fight to the death to stay that way. If something bad happens because I chose to ignore the ramifications of ignorance I smile and shine it on. My ignorance either caused a problem or made it worse. Mea culpa. My aged housekeeper in Oaxaca put her hands and frowned. " let me explain something to you senor..."

"All your life information is filling your head. When you grow old your head gets full. At one point or another your head gets full. Then something very unimportant can go into one ear and push something very important out the other ear".

All I know is if I do not educate myself before I buy something (usually very expensive) I am likely to end up screwing myself. Browbeating oneself in a mirror is not good for the ego. A person can be their own worst enemy. Read! Educate yourself! Study!
Gene_Ginny
Explorer
Oct 23, 2015
MEXICOWANDERER wrote:
.... Then he cursed me when I recommended his returning to Arizona or Texas and purchase a used one ton dually. "That isn't the @#$%^&! answer I was looking for!"......
But the salesman said I could tow it just fine. :R That was the answer he wanted .... even if it would have been the wrong answer. :S
MEXICOWANDERER
Explorer
Oct 22, 2015
Ooooooooo I like this new Buggati!

Can you drive?

Well, er, ah...

E CAVEAT EMPTOR

Please keep in mind that FEW if ANY recreational vehicles are set up to boondock right off the showroom floor. They are almost pure grade Power Pedestal Princesses. half million dollar MCI coaches with 2 8-D batteries in the early nineties. Wotta laugh! Good until around 2AM.

First mistake was believing Herb.
Second mistake was the purchaser not investigating the issue via the wealth of internet iformation before purchase.
Third mistake was not conducting a shakedown overnight before the trip

I have an ultra-bright (gift) flashlight that is incredible. For twenty minutes. 5-watts and three AAA batteries.

Or the guy who destroyed a 1994 Ford brand new pickup by hauling a 38' Teton trailer? Nobody told him an F150 wasn't a good mate for his Teton. Madder than hell when it played Laurel and Hardy in Manzanillo. The trailer squashed the pickup damned near flat against the spring stops, but sticker in gear and head out. He paid a King's Ransom in repairs before he(un-encouraged) asked for my advice. Then he cursed me when I recommended his returning to Arizona or Texas and purchase a used one ton dually. "That isn't the @#$%^&! answer I was looking for!"

IMPLIED MERCHANTIBILITY is a term folks should acquaint themselves with. When a conflict with reality disproves implied merchantibility then there are consumer laws and legal actions that can be taken.

Something like me purchasing a $15,000 computer server then finding out it doesn't do Windows.

Go figure...
CA_Traveler
Explorer III
Oct 22, 2015
mkirsch wrote:
...and if you just paid $100,000 for a rig that came with a compressor fridge, don't you think it would've come set up to actually run it?
Absolutely NOT, but that is the difference between a person that has bought a few cars that mostly do what's stated and an experienced RVer.

I feel compassion for the OP but from what he's posted his rig is not designed for overnight camping w/o utility power. Maybe he can improve the TV charging but overnight stays are going to require utility power, gen, more batteries, solar, etc.
time2roll
Nomad
Oct 22, 2015
Don't worry the OP did not seem to take to any of the great advice given or look into possible solutions.

Just run the Onan into the night....
mkirsch
Nomad II
Oct 22, 2015
red31 wrote:
MEXICOWANDERER wrote:
Ya think maybe - just maybe a bank of AGM batteries and a high output alternator is outside the realm of intelligenge to obtain ABSOLUTELY TROUBLE FREE REFIGERATION/FREEZING?

Yes and that is why the original post.

...and if you just paid $100,000 for a rig that came with a compressor fridge, don't you think it would've come set up to actually run it?

You shouldn't have to get a 4-year electrical engineering degree to figure out that you need install 500lbs of batteries, a flux capacitor, and a matter-antimatter intermix chamber to keep your food cold. It should just be cold.
MEXICOWANDERER
Explorer
Oct 22, 2015
I love it when an OP asks definitive coherent questions and they are answered by a raft of arm-twisting personal opinions based on a severely limited experience by one single person. Some companies tried pulling similar stunts on my clients and that is how I made my living - shoveling my way through 1.0% reality and 99% arm twisting opinion. Yes this still makes me cranky. Those that don't like it can sue me. Answer the question first. "My opinion is" follows, and de-fuses the air of hyperbole.
Grumble Grumble Snort
red31
Explorer
Oct 22, 2015
MEXICOWANDERER wrote:
Ya think maybe - just maybe a bank of AGM batteries and a high output alternator is outside the realm of intelligenge to obtain ABSOLUTELY TROUBLE FREE REFIGERATION/FREEZING?

Yes and that is why the original post.
MEXICOWANDERER
Explorer
Oct 22, 2015
Never have tried to use a screen door on a submarine. My heavily insulated force draft 18 cf consumes 58 amp hours in 24-hours. I had to convert and adjust 12 to 24 volts for you. Start engine. 400-amp Niehoff alternator looks at it's task list and laughs it's ass off. Preparation-preparation- preparation. But I will say this seriously - that Samsung has saved me many many thousands of dollars of wasted food and needless trips to distant "gas" plants and replacing wasted food. When I shop I can put a lot of food in that 5-CF freezer and on a 100F day the ice cream comes out rock hard.

I would not go back to gas if someone paid me a thousand dollars and stuck a gun to my head. Ya think maybe - just maybe a bank of AGM batteries and a high output alternator is outside the realm of intelligenge to obtain ABSOLUTELY TROUBLE FREE REFIGERATION/FREEZING? On a hundred degree day even the door shelves maintain 39F and the freezer -5F. Butane fills are reserved for hot water heating but I have a HEAT EXHANGER off of engine cooling with convection circulation with check valve. No can do on a tow rig but I am free forever of the idiocy of substandard food preservation and MIS-ENGINEERED absorbsion manufacturing. I know what pissed off hydrogen atoms do to steel and sheet metal piping is a cruel joke. It takes thought and planning to do a conversion to freon but hey you guys haunt a tech forum so what's the issue? My refrigerator will be trouble-free GUARANTEED just like it has been since 1994. And I am free of worries about Listeria Shigella and Tomaine. Wotta hoot.
RJsfishin
Explorer
Oct 22, 2015
I tried to think it as a funny, but then realized it as just plain ignorance.
MEXICOWANDERER wrote:
RJsfishin wrote:
I can hear the salesman now,......"yes, for 100 thousand, it should work for dry camping"

You do know the reason they make RV propane fridges ??

¡Si!

To hurl out the door. They make great landfill.