Refrigerator and 12v battery charging while driving (New Zealand report too)

[kmcintyre]

We just got back from a 1 month campervan trip in NZ. Awesome. Only saw 1 camper in a truck but they sure do have a lot of options there in terms of diesel trucks and cars that we'll never see here. Most 1/2ton trucks and small diesel cars are pulling the same loads as we see in the US. Large trailers, etc. and we can't even get those cars/trucks (Toyota, Nissan, Ford, Fiat, MB, etc. all have trucks w/ diesels).

On to my question and observations:
We had a VW Eurovan/Campervan with a 1.9L diesel, 5 speed, gray water, sink, stove, refrigerator w/ small freezer (like you see in a hotel), etc. This unit when plugged in ran all the accessories, charged the battery, etc. Had a small solar panel on the roof (looked like a flexible unit; not very large). We bought 1 bag of ice the whole time we were there and we made a lot of cocktails, etc. The freezer part (maybe 6" in height) was amazing. We only used shore power maybe every other day. You could hear the refrigerator cycling at night too.

My question. How in the heck did the battery stay charged? Yes, the solar helped although not a lot of days of full or partial sun.

We only have the 3-way refrigerator and it eats up the battery. Can we put it in the 12v mode while driving (effectively charging the battery as the refrigerator drains it)?

Since our Eagle FWC is older, we also can't run the lights, charge the battery, etc. when on shore power. How difficult is to add that and what all do you have to do? I assume you need a converter, etc. but where do you splice it in? What does FWC and ATC use?

Thanks.
Kevin

 

[Kispiox]

I have spent a lot of time in NZ and agree re small diesels. The environmental lobby and fuel tax assessment historically has retarded small diesel development in the US. Ram has a half ton small clean diesel if you can stand the wait. They are selling like hot cakes. I have a Ford 6.7 and average overall 16.2mpg with full time FWC and sometimes pulling a boat. The 6.7 is way more power than what I need for a FWC and boat. It only downshifts downhill.

Anyway there is much about the 3way refer subject here if you search. Yes, not supposed to but I run with three way on gas while underway. Everyone does but the FWC lawyers will advise otherwise. Gas is just as, if not more efficient than AC. There is no issue with wind while driving. There is very little gas consumption, as it is efficient in that respect too. I once left my camper unattended in an airport parking lot for two weeks in hot direct sun conditions and upon return everything was frozen solid. One more day and I would probably have been out of fuel and on the way to a stinky fridge. I knew the consumption pretty close from past usage.

 

[ntsqd]

HAve a look at the various discussions here about compressor fridges. They're a whole lot more efficient in their use of 12 volts than a 3-way is.

 

[BillM]

I'm guessing the fridge in your NZ camper was a compressor fridge since you could hear it cycling at night. The fridge in the camper we rented in AUS some years back was and it would run for a couple of days without driving. The comp fridges are much more efficient than 3 ways on electricity. We just got a compressor cooler and 100W solar setup for our Eagle and it will run for at least a week on solar alone, we haven't tested it for longer than that.

 

[Kispiox]

Yes, efficiency of DC on a three way is horrible if not useless. Most RV fridges now are just two way AC and Gas. The DC is only to maintain box temp temporarily and I never ever use it. I'm convinced the option is provided only because of lawyers. On gas it is extremely efficient. I freeze fish and it stays fresh frozen for months while on the road. The freezer is 20" x 5". There is much here on preferences. Having used and maintained compressor fridges on boats for years and now the two way, my preference is solid in the AC / gas camp. Put it on auto and do other more enjoyable pursuits. Plus, you don't hear it cycling at night.

The way I monitor box temp is to keep Popsicles in the freezer. I've yet to find one deformed beyond its original shape.

 

[Stalking Light]

We just got a compressor cooler and 100W solar setup for our Eagle and it will run for at least a week on solar alone, we haven't tested it for longer than that.

I have the Dometic 65 and 100w solar in my Eagle and the fridge wouldn't even run all night in the heat and humidity of the Everglades. I'm hoping it does better in the dry desert air this spring.

 

[wuck]

FWC (and I assume ATC) use an Iota DLS-30 converter charger. This will supply up to 30 amps at 13.4 VDC to run your camper and charge the battery on shore power. The converter has a standard AC line cord & plug, on my Hawk it is plugged into the back of the AC breaker/DC fuse box (Also an Iota item - PDC-30?). The output is connected directly to the main 12V fuse bus, and will charge the battery if the master switch is on. An IQ-4 module can be added to the converter [SIZE=14.3999996185303px](simple plug in) for a vastly improved charge [/SIZE]profile for lead-acid batteries.

DLS-30 Manual, IQ4 Manual, Elixer Manual (A few FWC have this one)
--
Pat

 

[craig333]

I didn't realize the IQ4 module was so inexpensive. I rarely use shore power but I'm better prepared now.

 

[PaulT]

I have the Dometic 65 and 100w solar in my Eagle and the fridge wouldn't even run all night in the heat and humidity of the Everglades. I'm hoping it does better in the dry desert air this spring.

Charlie,
I have the Dometic 110 and have been learning about living with solar power & refrigerator with mixed results. In the mountains last summer, with some shade, I couldn't keep the batteries charged because the fridge ran all the time. In DVNP, earlier this month, I was having a similar problem. The control setting was between 5 & 7. I started experimenting with the setting and found that above 5, it ran almost all the time. Below 3, it wasn't cold enough but did cut off. From a little above 3 to about 4 3/4, it cycled on & off and was cool enough. We came to an uneasy peace over the 10 days or so in temps ranging from a low of 20 to a high of 95 without losing any food.

Before leaving, I had filled the freezer compartment with frozen blue ice packs to occupy the empty space around the frozen food. I think they provide some thermal inertia. I had bought a portable solar panel and used it in early morning which allowed me to get a good start on recovering charge but used it only for a couple of hours then relied on the roof top panel. Experiment with your fridge setting to see if you can find a sweet spot. Good luck.

Paul

 

[ntsqd]

Adding a thermostat and 80mm computer box fan to force circulation at the back of the fridge made a notable improvement in performance of our 3-way. I put the fan & t-stat right at the upper vent pushing out. The TriMetric barely even notices that it's on. It wasn't the Silver Bullet, but it will help keep them colder.

 

[Stalking Light]

I do the same thing with blue ice packs and have added a little fan. I also have a thermometer and try and keep the temp below 40, but in FL it stayed above 80 outside even at night and the fridge ran all the time. It seems to do a lot better when the humidity is lower but I am still tweaking.

Once the batteries get low enough the battery separator clicks in and out when the motor is running so it's even harder to charge back up.

 

[BillM]

Stalking,

We're running a smaller cooler (cf-18) which uses about half the power of yours and have a 100 amp hour battery. Ours should run 3-4 days even with no solar input. I would expect that yours should run for a day or two if your battery is getting fully charged. I wonder if your alternator can put out enough to fully charge your truck and camper batteries. Another issue could be the long wire run to the camper and too small a diameter wire. Good luck figuring it out.

 

[Stalking Light]

The batteries showed fully charged on shore power before I left home and were again fully charged from the alternator when I got back. I'm hoping it was just the 80 degree temps around the clock and 80 percent humidity, but I'm still checking things.

 

[BillM]

Could be, we are blessed with cool night time temps and low humidity where we wander.

 

[Stalking Light]

I had an Engle 45 in my FJ when I spent the summer volunteering at Hovenweep and it would run fine all week from an Optima and 60w solar. I think(hope) cool nights and low humidity are key. I'll be heading to the southwest in a few weeks for about a month so I will have plenty of opportunity to test that theory.