power for truck fridge in Lil Snoozy

[vmj5674]

We are about 5 months out from our Snoozy build out and are getting pretty excited. And with the excitement comes lots of questions. So, today's question has to do with truck fridge. We have talked with Richard and he will install it. It is a 12 volt, but of course, campsites will run on 110. How do we go about reducing a 110 volt AC to a 12 volt DC? We would likej to be able to run it off of the tow vehicle, generator, and electrical power at a camp site.

The question and answer are way above my pay grade. Just plalying secretary for my husband.



Thanks,
Violet Johnson

[mszabo]

This one is 8 amps

https://smile.amazon.com/Converter-H...ighter+adapter

[Alex Adams]

Will you have an on-board battery and converter/charger? If yes, you don't need to convert 110 with anything else. Just hard-wire the fridge into your 12 volt circuits. If you don't want to do that and there is a 12-volt outlet that runs off of the battery, plug the fridge into it. When the tow vehicle is connected it will charge the battery that will run the fridge. When plugged into shore power, the converter/charger will charge the battery which will run the fridge. When connected to the generator, the converter/charger will charge the battery which will run the fridge. And if you decide to put Solar in the future that will charge the battery which will run the fridge.

[Joe A.]

buy the model that runs on ac or dc. it switches by itself. that is what i did.

[David B.]

Agree with post #3. Why pay for an option that is not needed. We have been using ours since 2014, and only have a smart charger to charge the battery while on shore power, 12 volt line from the tow vehicle while driving, and solar or a generator for when off-grid camping.
Dave & Paula

[charlsara]

Originally Posted by David B.

Agree with post #3. Why pay for an option that is not needed. We have been using ours since 2014, and only have a smart charger to charge the battery while on shore power, 12 volt line from the tow vehicle while driving, and solar or a generator for when off-grid camping.

Dave & Paula

That is exactly like ours. Even if it ran off the battery full time as long as your charger can keep up you will be fine. I believe Richard is putting a 35 amp converter in the newer units.

[Mitzi Agnew-Giles]

You may want to get an extension cord for your electrical line. Snoozy hs a short cord. The extension cord opens up a lot more parking configurations.

[k0wtz]

a semi-truck tractor has a huge 12v system in it a car wont handle it for long I wouldn't count on it running off a trailer battery for long either. if you have 110v buy appliances for that you can maybe run a 12v fridge while you are running down the highway but I wouldn't do it.

plug that stuff into your 12v system you are putting a big strain on your alternator. expensive

bob

[Alex Adams]

I have seen portable and permanent 12 volt compression fridges that draw anywhere from 2 to 8 amps max. Those should work fine with your trailer battery but are pricey. I have a portable Dometic right now that draws 7 amps when running (which isn't often). I plan on putting in a permanent Nova Cool fridge in my trailer that draws 2.2 amps when running. I do have solar charging when I don't have access to AC power. I don't think any of these would over-stress your alternator if plugged into the cigarette socket.

[David B.]

Originally Posted by k0wtz

a semi-truck tractor has a huge 12v system in it a car wont handle it for long I wouldn't count on it running off a trailer battery for long either. if you have 110v buy appliances for that you can maybe run a 12v fridge while you are running down the highway but I wouldn't do it.

plug that stuff into your 12v system you are putting a big strain on your alternator. expensive

bob

Bob, your posting is accurate for an absorbtion refrigerator (propane/12volt/110) but is not accurate for the danfoss compressor such as Nova Cool or Truckfridge as examples, like those used in the Lil Snoozy.
Dave & Paula

[rbryan]

Originally Posted by David B.

Bob, your posting is accurate for an absorbtion refrigerator (propane/12volt/110) but is not accurate for the danfoss compressor such as Nova Cool or Truckfridge as examples, like those used in the Lil Snoozy.
Dave & Paula

Exactly. Different animal. As for running my absorption fridge on DC 12V, I never do it. Not because of any "strain" on the alternator, but because it doesn't cool. A Danfoss compressor fridge will cool to the point of freezing things rock hard, if you want it to.

[lgboro]

I have a NovaKool R-5810 that should be delivered in the next couple of weeks. In researching forums and talking to engineers the my battery company ReLion, Progressive Dynamics the maker of my charge system and NovaKool as long a you have a good battery you should be able to run a compressor fridge especially if you camp with power. It will pull between 30 and 90 amps per day depending on outside temps so I would advise a robust battery system if possible. I run a 300 amp lithium battery and 350 amps of solar on my camper but I mainly boondock so your system should not require that much capacity to meet your needs. However, you need to monitor your anticipated amp draw if you need to operate off grid and plan accordingly. You could carry a generator for the high amp times during the day as needed, I carry one but don't expect to need it.

[redbarron55]

I have a very old Norcold swing compressor fridge and it runs on either 12 or 120 volts and draws around 40 watts of power when running which it is around 50% of the time.
Measuring with my Watt meter it averaged 17 watts per hour or 24 X 17 watts per day for 408 watts.
In good sun my 100 watt solar paned can handle this.
The drawback is that the swing compressor is fairly noisy when running.
The Norcold I have is 704DE.
Remember the power drawn by a fridge needs to be figured as an average not peak.

[Steve L.]

Technically, I suppose, everywhere Larry mentions "amps" he's really referring to "amp hours". (I'm an engineer. I can't help it. Send money to help the poor engineers...)
http://bcn.boulder.co.us/~neal/engineerhumor.html

[Steve Carlson]

With regards to battery power and fridges, I have an Engel portable fridge that I use for overlanding. It runs on 12V or 120V, and it's swing compressor draws an average of 1 ah (varies with ambient temps and usage). I also run a CPAP while sleeping that takes about 1.3 ah to run.

My FJ Cruiser has a single Odyssey battery that has about a 66 ah capacity if memory serves. It has always started up briskly the next morning after powering the fridge and CPAP overnight.

I do carry one of those little lithium jump starters as backup, but have never had to use it.

I just bought my camper in November, but I see no reason a single AGM battery in the camper won't be able to do the same thing.

[redbarron55]

When I was working (?) as an engineer I had young engineers who I said that they called themselves engineers, but couldn't even run a train!
I fixed that by assigning them to work on our GE Diesel Electric locomotive (to broaden their experience some)

[lgboro]

I'm not an engineer (my son is) but its not rocket science either, one would have to audit usage to allow one to be comfortable that any system will suit their needs. We all have different camping styles and very different power needs. I use more power than most because I carry more wants to supplement my actual needs so it would be nearly impossible for anyone to guess my power needs in a useful way.

[CarlD]

I am planning on using the truckfridge tf130 in my lil hauley build out. The power supply/battery charger in the trailer will be more than adequate to run it on 12 volts (no need for 120 VAC operation). If you run it while driving your tow vehicle you should have no problem running it because the max current draw by the fridge is 4.4 amps, reducing to 2.2 amps after the fridge reaches temperature. The only issue I can think of is if the wire size in your tow vehicle is small and, consequently, the voltage drop is to large it may draw down the trailer battery charge. I added an additional 10 awg wire in my truck and ran it directly off the fuse box under the hood thru a 30 amp fuse to the trailer plug. I also added a relay controlled by the original wire so the power to the trailer turns off when the truck turns off. I did this primarily to reduce voltage drop so the trailer battery would charge better while driving. Hopefully this helps and is not to long winded!

[CarlD]

Originally Posted by Steve L.

Technically, I suppose, everywhere Larry mentions "amps" he's really referring to "amp hours". (I'm an engineer. I can't help it. Send money to help the poor engineers...)
Engineers Explained

Nice list of engineer attributes. I might add that engineers will never complete a project because they keep improving it as they go along. Hence the quote on one of our service supervisors wall "Sometimes you have to shoot the engineer and move on"

Carl EE 72

[lgboro]

I'm planning an extended Alaska trip this summer and should recoup a some of the cost this summer with being comfortable with out campground services. I had already made up my mind to pull the trigger on my solar and battery prior to calling the engineers but I did appreciate the feedback as this project has some significant up front cost. I was able to program my solar controller but had to buy another charge system for the camper. Already had the solar installed so I decided to get the system I thought would last for a number of years. I don't know if I will break even with reduced camping fees or not but I suspect I will as we camp a little over half time now mostly boondocking.