Driving with fridge on DC?

[BritCanuck]

Is this doable assuming the trailer batteries are kept back charged from the tow vehicle? Or is the load too much and you still end up with dead trailer batteries when you get to your destination?

[SRS]

[QUOTE=BritCanuck;467664]Is this doable assuming the trailer batteries are kept back charged from the tow vehicle? Or is the load too much and you still end up with dead trailer batteries when you get to your destination?[/QUOTE

Yes and no. A lot depends on how the trailer is equipped. Is the fridge
absorption or compressor (I'm guessing absorption from your question), how much solar if any do you have, what batteries are installed and how many Ah. Driving distance can also be a factor and does your destination have full hookups or are you boondocking.

Personally I always run my fridge in DC but it's a small 4 Cu.Ft model, I have 190 watts of solar, 200 Ah lithium batteries. My F-150 doesn't provide much charge due to distance from the alternator to the batteries and wire gauge even with a DC-DC charger.

Lots of people prefer to run their fridge on gas since DC also equals Dead Car, but technically and legally, you shouldn't have an open flame burning when fueling so that means stopping before you fill up, switching the fridge to DC, filling your tow vehicle and pulling of again once your away from the pumps to switch back to gas. At big gas stations with the room, you can probably do all that on site. So, lots of options.

[huskersteffy]

I assume you have an absorption fridge like me and not a compressor fridge.

I have a Ford F-150 as well with the max-tow package. I did try running the fridge on 12V one trip when the fridge stopped working on propane. When going down the road, the truck battery was fine because the alternator kept it charged, but the fridge just does not keep things cold on 12V power. I made sure to disconnect the 5 pin cable when we stopped for lunch or gas just to make sure the fridge did not draw the truck battery down when parked.

Once I figured out the problem with running on propane (loose electrical connection at the back of the fridge) , I went back to that propane while driving or boondocking.

For those that have a compressor fridge, I'm curious does the fridge still draw tow vehicle battery power when the vehicle is off?

[HABBERDABBER]

The wiring size within the tow vehicle and to the trailer is typically not adequate to support the 12V DC load. The tow vehicle alternator may not be adequate either in output capacity.

With effort and money, it can be done, but upgrades in those areas are required.

[JohnK]

Chris, the fridge in our 21C draws 22 amps on DC only. Knowing that, even with a 230 amp hour battery and 390 watts of solar panels on the roof, we tow exclusively with the fridge on propane unless we want to draw our 230 amp hour lithium battery down to 50% - 60% state of charge for storage. Not knowing what you have for a tow vehicle alternator/battery/trailer battery bank, my guess is that electrically you will not not come out even towing with your 3 way fridge set to DC and you'll be better off towing with your fridge on propane setting.
John

[oldwave]

I have a 400 amp hour battery bank with 300 watts of solar and a dc to dc charger that’s only 10 gauge so maybe only charging at 5 or 6 amps. We have an 8 cubic ft 2 way. I tow with the inverter powering the fridge. We tow short days 4 to 6 hours. I might lose 10 to 15% of the batteries, which charges quickly up with shore power. We have a victron inverter/charger which is fairly efficient. Given my former role as a safety officer for one of the National Parks I worked in, propane off at the tank while towing is my preferred method. One of my upcoming upgrades will be proper wiring for a new Victron XS dc to dc that will charge up to 50 amps. In my old Escape that had lead acid and a 3 way I did tow short trips with the dc on . Lithium will be the preferred chemistry to do this and a robust bank and robust solar . Still to me safety is paramount. A road gator could take out a propane line under the trailer to catastrophic consequences. We put 26000 miles on our trailer in 18 months we have owned it with lots of road conditions and campground rough roads. This is right for us, your approach may be different and the risk assessment is different for many owners. My ultimate goal will be 660 ah battery bank as we are upgrading to a Victron 330 amp hour battery now and another a bit later in the summertime. Ymmv

[brroberts]

I prefer to run 12v fridge while driving, but can’t. Once I install a proper DC power supply from the truck, I will go back to towing on DC. Currently we run on propane as most do, but I agree it’s a potential safety issue.

[Centex]

Originally Posted by oldwave

.... One of my upcoming upgrades will be proper wiring for a new Victron XS dc to dc that will charge up to 50 amps. ...

In order to realize the full 50A capability and assuming a distance of 5-10 meters from TV battery to trailer battery, that will require 4AWG cable for that run, a 'dedicated umbilical' via a connector between the TV & trailer other than the 7-pin RV connector (e.g Anderson PowerPole or similar), is that correct?

[oldwave]

Originally Posted by Centex

In order to realize the full 50A capability and assuming a distance of 5-10 meters from TV battery to trailer battery, that will require 4AWG cable for that run, a 'dedicated umbilical' via a connector between the TV & trailer other than the 7-pin RV connector (e.g Anderson PowerPole or similar), is that correct?

Yes that is exactly the plan . My tow vehicle has a snow plow package that includes a 400 amp alternator. Plus proper fusing at the battery .

[Centex]

Originally Posted by oldwave

... My tow vehicle has a snow plow package that includes a 400 amp alternator. ...

Whew, more than double what I've got, congrats!

You're in great shape to handle an extra 50A load

[Ron in BC]

Originally Posted by brroberts

Currently we run on propane as most do, but I agree it’s a potential safety issue.

I view driving on the freeway as more of a potential safety issue.

Like discussions about power awnings and framed windows this is one discussion that will go on and on.

Ron

[sunrisetrucker]

Originally Posted by Ron in BC

I view driving on the freeway as more of a potential safety issue.

Like discussions about power awnings and framed windows this is one discussion that will go on and on.

Ron

I agree with you Ron. In fact if you want to be really safe don't drive with a gas or diesel powered vehicle because those fuels are an extremely dangerous fire hazard.


(I hope I haven't started an EV debate now )

[oldwave]

Here you go.

https://www.cbc.ca/news/canada/montr...fine-1.3306336

ymmv

[Mesa]

Originally Posted by oldwave

I have a 400 amp hour battery bank with 300 watts of solar and a dc to dc charger that’s only 10 gauge so maybe only charging at 5 or 6 amps. We have an 8 cubic ft 2 way. I tow with the inverter powering the fridge. We tow short days 4 to 6 hours. I might lose 10 to 15% of the batteries, which charges quickly up with shore power. We have a victron inverter/charger which is fairly efficient. Given my former role as a safety officer for one of the National Parks I worked in, propane off at the tank while towing is my preferred method. One of my upcoming upgrades will be proper wiring for a new Victron XS dc to dc that will charge up to 50 amps. In my old Escape that had lead acid and a 3 way I did tow short trips with the dc on . Lithium will be the preferred chemistry to do this and a robust bank and robust solar . Still to me safety is paramount. A road gator could take out a propane line under the trailer to catastrophic consequences. We put 26000 miles on our trailer in 18 months we have owned it with lots of road conditions and campground rough roads. This is right for us, your approach may be different and the risk assessment is different for many owners. My ultimate goal will be 660 ah battery bank as we are upgrading to a Victron 330 amp hour battery now and another a bit later in the summertime. Ymmv

With modern trucks, I think this is the only way for this to work. Newer models now have sophisticated charge controllers that shut-down the alternator, once the vehicle battery is charged, to improve gas mileage (CAFE)

[SkipperClyde]

When we had a Casita Spirit Deluxe we towed exclusively with the fridge on DC. Had to because the propane was not auto ignition and would blow out going down the road. Towed with a 2006 Tundra limited. Never had any problems. No solar. We did light the propane when we stopped for extended periods.

[tazzilla]

I just covered 1400 miles last month towing my 17b in 12v mode for the fridge. I tow witha 2005 4runner V8 and factory tow package. I never had a battery issue on my TV the whole trip and fridge temps were nice and cold the whole time. I honestly have never had a issue towing while fridge was on 12v. I have owned several rv's in the past 25 years and always tow in the 12v setting. I also start with a completely cool fridge before I take off and use the 12v setting

[7Gentex]

Originally Posted by oldwave

Here you go.

https://www.cbc.ca/news/canada/montr...fine-1.3306336

ymmv

The article below states the RV engine caught fire.....the article you referenced states RV owner was being fined for transporting an "excessive" volume of propane. Neither states anything about propane being the problem except for being in excess of the "allowed".

https://www.cbc.ca/news/canada/montr...airs-1.3259896

[Earl]

I tried it with our19', and at end of a few hundred miles its battery was down more than I wanted. On a previous setup with an older Land Cruiser TV and larger camper I had to add heavier wire in the TV, an Anderson plug, a dc-to-dc converter, and a low voltage cut out between the camper battery and the fridge.

[oldwave]

Originally Posted by 7Gentex

The article below states the RV engine caught fire.....the article you referenced states RV owner was being fined for transporting an "excessive" volume of propane. Neither states anything about propane being the problem except for being in excess of the "allowed".

https://www.cbc.ca/news/canada/montr...airs-1.3259896

The point is you drive in a tunnel or on a ferry and your propanes is on and there’s an accident you risk more than yourself, I’m not going to bandy words but take the risks your willing to. Me I’d rather not, I’ve seen too many accidents involving propane mobile or not. Escapes leaking propane stoves for instance.

Nuff said.

[7Gentex]

Originally Posted by oldwave

The point is you drive in a tunnel or on a ferry and your propanes is on and there’s an accident you risk more than yourself, I’m not going to bandy words but take the risks your willing to. Me I’d rather not, I’ve seen too many accidents involving propane mobile or not. Escapes leaking propane stoves for instance.

Nuff said.

Agreed, and illegal (and stupid) in most areas, as well as while refueling at a gas station...........but, wasn't my point.

Propane was not a contributing item to the fire/damage in the article referenced, except for fine related.

I've responded to "tens" of vehicle fires and a few propane (fixed and mobile) related incidents in a past life. A vehicle fire in a tunnel, or on a ferry, would be a really bad day, propane or not.

Propane tank fire school will really get your attention

Getting a propane tank to the point of a BLEVE, is a whole different level of danger.....and takes a pretty hot fire impinging on the tank in the right (wrong?) area.....while leaking propane from a low pressure / regulated line, not really a big deal IMO, unless it has been accumulating in a confined space (like the oven fiasco).............