How to Keep The Refer Cold While Driving Down The Highway

[George Johnson]

There's been a lot of talk on one of the other forums lately about the problems owners have had keeping their refrigerators cold during long days on the road. The consensus seems to be that most tow vehicle alternators are not up to the task of both maintaining the tv electrical system and operating the refrigerator while driving down the road. The problem sometimes takes as long as a week to show, but apparently the tv battery eventually becomes too discharged to start the tv at some point down the road, which if it were to happen in my world, I would consider it to be a bad thing.

I tow my 2009 E 19 with a 2017 Nissan Frontier, which as near as I can tell has an alternator that peaks out at about 90 watts output, and that seems to be at about 4,000 engine RPM. I don't know how much the truck requires to run, and I don't know how much my Dometic RM2510 refer requires when operating on 12 volts.

Most of the folks on the other forum seem to gravitate to using their propane cooling systems in order to avoid discharging their tv batteries. The Escape 19 owner's manual that came with my trailer (I'm the second owner) is very explicit in recommending against this practice. That advice makes sense to me. It might discourage tailgaters if the trailer catches fire, but I don't see any other advantages to recommend the practice. I even seem to recall that it is illegal to run on propane while moving in some states. Tunnels and gas stations could also create some exciting moments.

Has anyone here had this battery drain problem, and how have you addressed it? Have you had to install higher output alternators?

I've got dreams of a couple of longer trips later this year and I hope to avoid as many difficulties as I can. My little A-Liner was not nearly so sophisticated!

 

[Brian B-P]

The problem is wiring from the tow vehicle's charging system to the trailer's battery, not the charging system itself.

The "90" spec would be amps, not watts. Any modern alternator can put out much more than the 10 amps or so that the refrigerator needs, at any engine speed used while driving (although maybe not at idle).

Still, the system may not keep up, because there is so much voltage lost between the point where the tow vehicle's charging system maintains 13 to 14 volts and the terminals of the trailer battery that the trailer's battery (not the tow vehicle battery) discharges instead of charging. This is especially bad when the tow vehicle charging system lowers voltage to save fuel, which is why the tow/haul mode in some trucks triggers the charging system to not use this voltage reduction logic.

If the tow vehicle battery gets run down, that's probably from the trailer draining it when the tow vehicle engine isn't running, and the trailer is still plugged in, and the tow vehicle is missing the shutoff relay that it should have.

 

[steve dunham]

You could upgrade your vehicles alternator , your vehicles and trailers wiring , add roof top solar , a DC to DC converter , larger batteries and hopefully it will work
Or you could just run the refrigerator on propane and be done with it
The choice is up to you

PS ; I tried running my refrigerator on 12 VDC but after arriving at my destination with a drained battery on several occasions I decide to follow the example set by others —-
PROPANE !!

 

[Rossue]

Exactly.

 

[Brian B-P]

I even seem to recall that it is illegal to run on propane while moving in some states. Tunnels and gas stations could also create some exciting moments.

The propane tank valve does need to be shut off in a few tunnels and most or all ferries. The flame of any appliance should be shut off in a fuel station, but there's no reason to turn off the propane. There is no rule anywhere against using propane while driving down a highway.

All of this has been discussed many times in this forum, and probably every RV forum.

 

[gbaglo]

My trailer has the RM2510 and it only runs on 120V or propane. It has no 12V setting.

I travel with the fridge on propane. It works. There are no laws prohibiting running on propane. There are regulations about shutting off propane in some tunnels and on ferries.

 

[Doug2000]

We always ran the fridge on 12 Volt till our 2018 trip to the southwest. The fridge couldn't keep up with the 100 deg heat. Now after a little forum search, I run propane.

DONT FORGET TO TURN THE FLAME OFF BEFORE YOU FUEL UP.

Also keeps the batteries strong.

 

[rubicon327]

...and I don't know how much my Dometic RM2510 refer requires when operating on 12 volts.

A RM2510 12V electric element is 175W or almost 15 amps.

Most of the folks on the other forum seem to gravitate to using their propane cooling systems in order to avoid discharging their tv batteries.

For good reason. If you don’t have a very robust charging system incorporating the tow vehicle (and possibly other equipment like a DC-DC charger) and/or solar you can arrive at your destination with a dead trailer battery. Not only is this very inconvenient if you are boondocking it is unsafe. The trailer breakaway system relies on the trailer battery to activate the brakes in the unlikely event the trailer were to become disconnected from the tow vehicle.

 

[Jordan-ESC]

Here is a simple solution if you have the larger fridge: just keep a few extra ice packs in the freezer, and when it is time to drive, move them down into the fridge. Then re-freeze them at night when you get to your destination.

 

[gbaglo]

A RM2510 12V electric element is 175W or almost 15 amps.

I don't understand. Is there a Dometic RM2510 with a 12V electric element and a Dometic RM2510 without a 12V electric element?
Two different fridges with the same model number?

 

[rubicon327]

I don't understand. Is there a Dometic RM2510 with a 12V electric element and a Dometic RM2510 without a 12V electric element?
Two different fridges with the same model number?

Yes, there is 2-way and a 3-way RM2510. Maybe Reace put 3-way in some of the early 19’s (2009)? Our 2010 has the 2-way.

 

[gbaglo]

Yes, there is 2-way and a 3-way RM2510.

Sounds like Dometic.
When I was ordering my trailer Reace explained that the 12V 3 cu. ft. fridge would use all the power the tow was capable of providing, leaving none to charge the battery. He said if I left a camp with the trailer battery depleted and ran the fridge on 12V, I would arrive with a depleted trailer battery.

That's why I opted for the 5 cu. ft. two-way RM2510. There was no mention of a three-way RM2510.
Looking up the RM2510, I see no reference to 12V operation.

 

[rubicon327]

There was no mention of a three-way RM2510.
Looking up the RM2510, I see no reference to 12V operation.

Dometic literature is poor. They hint at 12V operation in the service manual.

 

[gbaglo]

Dometic.
Maybe you can find instructions on how to turn that 12V unit on?
The only reference to 12V that I can find is that the fridge uses 12V leads to the igniter for propane operation.

 

[Jim Bennett]

DONT FORGET TO TURN THE FLAME OFF BEFORE YOU FUEL UP.

Despite your yelling at us, you do realize that the vast majority of people do not do this. I never have. We have done an informal question on it here, and most do not turn it off.

But if you do choose to go to the trouble, there is no harm in doing so.

 

[h2owmn]

I do what Jordan does. Three 28 or 32 oz gatorade bottles rotating into the fridge/freezer and refreezing at night if i'm doing one night stops. If it's REALLY hot out and i'm doing a lot of miles, I have run on propane, but I try to avoid it.

 

[rubicon327]

Dometic.
Maybe you can find instructions on how to turn that 12V unit on?
The only reference to 12V that I can find is that the fridge uses 12V leads to the igniter for propane operation.

This is from an older Dometic "Service Tips" document. The fridge could be equipped from the factory with 3 way functionality but many are just 2 way. DougG just recently installed a 12V element on his 2-way RM2510 version so that he can use 12V DC. Was going to add a DC-DC charger and some heavy gauge wiring too. Not sure how it has worked out as he hasn't reported any results since he hasn't had warm weather yet to test.
http://www.escapeforum.org/forums/f8/adding-12v-heating-element-to-rm2510-fridge-16224.html

 

[fudge_brownie]

While fueling my vehicle with a running refrigerator in tow I do not turn off the refrigerator. I carefully choose a pump where my trailer is positioned away from the pumps.

That almost always means it is hanging into the driveway/access area of the pump island. I check to be sure there is suitable clearance for other vehicles. I never position the trailer so it is adjacent to a pump where someone may be fueling on the other side of the island.

 

[Mary F]

I do what Jordan does. Three 28 or 32 oz gatorade bottles rotating into the fridge/freezer and refreezing at night if i'm doing one night stops. If it's REALLY hot out and i'm doing a lot of miles, I have run on propane, but I try to avoid it.

Same here. We also carry a small cooler for drinks, to minimize fridge door opening when in camp. It doubles as a backup for stuff that must stay very cold when underway (meat and milk, mostly).

 

[Mike Lewis]

While fueling my vehicle with a running refrigerator in tow I do not turn off the refrigerator. I carefully choose a pump where my trailer is positioned away from the pumps.

This is what I do as well.