trailer information

[maverick_935]

bought a new trailer and it has an inverter and a normal fridge in it. found out on a trip the battery for the fridge only lasts a couple of hours. it is not hooked up to the trailer battery or the truck for charging.

Dealer tech said my truck couldn't charge both betteries.

does anyone else have a trailer with a seperate battery for their fridge. what have they done with this issue

[rapidoxidationman]

A normal (compressor) fridge is a high amp item for a battery. Most camper fridges are propane / DC (no compressor, cooled with ammonia IIRC). Propane while stopped at your destination, DC while in transit cuz burning propane while you're moving is a no-no.

A battery isolator will charge your trailer battery just fine - I'm surprised your dealer didn't mention it.

Any decent RV shop will get you up to speed on camper fridges and battery isators.

[DmaxMaverick]

New (different) fridge, or a unit generator (with auto start/stop), or a LOT of electrical upgrade work on the truck.

Your truck can charge the batteries, but will not keep up with an AC-only refrigerator in OEM trim. You'll need to upgrade the generator and charging circuit to the trailer. The OEM wiring will not carry that current. You can add another alternator for an OEM dual setup, but it will still be well short of what's needed. Ideally, upgrade to duals, and use generators designed for your needs, as well as a dedicated charge circuit to carry that load.

I dry camp w/o a stand-alone generator and use the truck for all charging needs. (generator weight vs. toy and water weight trade-off) I have a single upgraded alternator and run a 2kw inverter for (mostly) entertainment system power (TV, sound, game systems, microwave, toaster oven, blender, etc.). I wouldn't consider running an AC-only fridge full time on batteries.

[EdHale]

New (different) fridge, or a unit generator (with auto start/stop), or a LOT of electrical upgrade work on the truck.

Your truck can charge the batteries, but will not keep up with an AC-only refrigerator in OEM trim. You'll need to upgrade the generator and charging circuit to the trailer. The OEM wiring will not carry that current. You can add another alternator for an OEM dual setup, but it will still be well short of what's needed. Ideally, upgrade to duals, and use generators designed for your needs, as well as a dedicated charge circuit to carry that load.

I dry camp w/o a stand-alone generator and use the truck for all charging needs. (generator weight vs. toy and water weight trade-off) I have a single upgraded alternator and run a 2kw inverter for (mostly) entertainment system power (TV, sound, game systems, microwave, toaster oven, blender, etc.). I wouldn't consider running an AC-only fridge full time on batteries.

I see no reason for a residential refrigerator in an RV. Even if everything is working properly to keep the batteries charged you are putting a lot of load on those batteries which are expensive and do wear out. I know residential refrigerators cool better, etc., but I too boondock occasionally and will never have one in any RV of mine. My Norcold will run for weeks on a single charge on a deep cycle battery and a 30 lb propane bottle.

[richp]

Hi Maverick,

You've innocently fallen victim to a modest trend in newer RVs -- putting 120 volt-only refers in travelling units. This is being done under the assumption that these units either will be at a full power campsite every night, or will be permantly parked at a power pedistal.

If your dealer told you that your stock RV battery/batteries would power the refer (through an inverter) for more than a matter of hours, then you were seriously mis-led. Without adding a rather large auxiliary battery bank, or (as noted in another post) some modifications to how your RV connects electrically to your tow vehicle, you are going to experience significant limitations in your camping abilities.

My personal first step in a situation like this would be to go right back to my dealer, and confront him with the reality of what he sold you. You could request/demand that the dealer replace (on his dime) the 120 volt-only refer you have with a typical propane refer. (That may require some changes in your cabinetry as well.) Or you could request he exchange your current rig for a unit that has a typical RV refer.

Unless your dealer is exceptional, you very well can expect resistance to either of these option, of course. In which case, I guess you'd be either stuck with the limitations you now see, the cost of a larger battery bank (think four 6-volt golf cart batteries in series/parallel), the cost of beefing up the electrical link to your truck, or paying for the refer swap out of pocket. None of which are very appealing, I'm sure.

(On review, there is another option. A small Honda EU1000 generator could give you enough juice to keep this going, at modest expense. However, despite how quiet the Honda EU series is, there are many campgrounds that do not allow generators at all, there are theft and re-fueling issues to deal with, and it's yet another sub-system to think about. But it could be cheaper than most of the other things I mentioned.)

FWIW, with regrets for your problem.

[DmaxMaverick]

I see no reason for a residential refrigerator in an RV. Even if everything is working properly to keep the batteries charged you are putting a lot of load on those batteries which are expensive and do wear out. I know residential refrigerators cool better, etc., but I too boondock occasionally and will never have one in any RV of mine. My Norcold will run for weeks on a single charge on a deep cycle battery and a 30 lb propane bottle.

I don't, and wouldn't, use or recommend one. Only offering alternatives, if it is necessary to keep it if it's already installed. I dry camp a lot, and as I said, my inverter use is mostly for entertainment systems. As you said, one LPG bottle and one battery charge will keep the RV fridge running for weeks at a time, which is what I use. Even DC power-optioned fridges don't run long w/o continuous battery charging.

[richp]

Hi,

Don't we have an rv tech on this board?

Maybe he has some thoughts on this.

[maverick_935]

i have referred it back on the rv place. i told them it was not acceptable and to figure it out. if need be to put a propane fridge in.

i do like the double door freezer on the bottom fridge tho

[richp]

Hi Maverick,

FWIW, I would hesitate to accept installation of an additional typical "deep cycle" battery as their solution. Still not going to solve the fundamental problem.

FYI, there are double door propane RV refers, but they are a lot more costly. You could ask for one, I suppose...

Here's hoping for a good solution.

[arveetek]

It is definitely a trend now to install residential refrigerators in travel trailers. Most of our "high-end" 5th wheels we have on the lot come with residential fridges now.

The benefits of the residential fridges are lower cost (you can get a really nice, much larger fridge with ice maker, water in the door, etc, for the same or less cost than a standard two-door conventional RV fridge), longer durability (most residential fridges will last for 20 years or more, while RV fridges seem to be hit and miss... most don't seem to make it past 10 years anymore), and more storage capacity.

The obvious drawback is the power supply. As has been stated, the RV manufacturers assume that the buyers of that particular unit will not be dry-camping or boondocking (camping without full hookups). Yes, you will need either a constant 120V source, such as a campsite pedestal or generator. It's possible to boondock with a good battery bank and large solar panels, but a lot of your power will be consumed by the fridge and inverter.

The RV's we sell have a pass-through inverter built in to the coach. This means that when you're plugged into shore power or on a generator, 120V AC passes through the inverter directly into the outlet that powers the fridge. As soon as 120V AC power is no longer present, the inverter kicks in providing 120V AC to the fridge.

Getting back to the original poster's question, we have not experienced any problems with the battery(s) going dead on our units while traveling down the road. As long as the tow vehicle's charging system is in proper working order, the tow vehicle will send a charge back to the trailer's battery(s), keeping up with the demand of the inverter and refrigerator. The modern refrigerators actually only pull a few amps, so it's not as a large of load as suspected.

If the RV in question has two separate battery systems, one for the coach and another for the inverter, and the inverter battery is not being charged while driving, then this is an obvious problem. However, I have not seen such a setup. The battery for the inverter should be charged from the tow vehicle while driving if everything is working correctly. There should be no need for isolators and such on most conventional towed RVs.

Generally speaking, we usually provide two 27 series deep cycle batteries wired in parallel on our 5th wheels with residential fridges and inverters. We have not had a single complaint that I'm aware of batteries going dead while driving due to this setup. Once in a while we'll find the customer's truck is not providing a charge to the trailer batteries due to a blown fuse or such, but this is not the fault of the residential fridge setup.

Now, as far as batteries going dead while parked, that's a whole different story.

If someone is currently shopping for an RV and wants to boondock, I would advise avoiding the residential fridge. However, for normal camping at an established campground, I would not be afraid of a residential fridge. In fact, I think it's a pretty good idea.

In all honesty, most RV's that come with a residential fridge are not suited well to boondocking anyway.... not only is the fridge a problem, but they are usually loaded with tons of electronics and other power-consuming devices....

Casey

[EdHale]

I don't, and wouldn't, use or recommend one. Only offering alternatives, if it is necessary to keep it if it's already installed. I dry camp a lot, and as I said, my inverter use is mostly for entertainment systems. As you said, one LPG bottle and one battery charge will keep the RV fridge running for weeks at a time, which is what I use. Even DC power-optioned fridges don't run long w/o continuous battery charging.

Agreed.

[rustyk]

I have a 3-way reefer in my coach (Propane, 12VDC, 120VAC); I run it on 12V on the road. I installed it a couple of years ago, and it was $1,200 and only 7.5 cu. ft. I ran my old 2-way (Propane, 120VAC) on an inverter underway. As noted, one gets more space and features with a residential. One of my good friends owns a large RV repair shop and he will not install an evaporative reefer. As a footnote, a friend has an all-electric RV reefer.

As far as the tow vehicle's being able to keep the reefer battery up, note that modern residential reefers use little power, and because they're better insulated, the compressor only has to run intermittently. While there may be a net drain while the compressor runs, it's a very short duty cycle, and the battery can catch up.

Many RVs run the reefer on propane while underway, but like arveetek noted, it should be avoided. A friend of mine blew a tire, and the steel cords took out his propane line; thankfully he noticed the leak right away and shut off the gas. Fortunately, he was in transit near my house, so I brought the flaring tools and tubing he needed to repair. My old motorhome had a 2-way, and I had a note on the dash to shut the reefer off when refuelling.

Another footnote, I replaced the 12V house batteries with 6V golf cart batteries in series - more capacity, and hardier.