Options for running a 120 VAC bar fridge while driving

[kmack67.km]

Hi,

I am new here but have been lurking for a few months; what a great forum. I am about to start with a 7x14' Cargo trailer conversion. For the foreseeable future I will mostly be camping in campgrounds with electrical hookup so I will be running a small ~4 cu-ft bar fridge on shore power while camping. I know this isn't necessarily the best option for camping but it is simple and relatively inexpensive for now. I am thinking of options to continue the cooling while on the road and have come up with the following:

1. Keep a large block of ice in the fridge while it is unplugged. I am guessing this will keep things cool for a day or so but it can be messy.
2. Install a marine battery in the trailer, connect a pure sine wave inverter to it (with short DC leads) and plug the fridge into it while driving. Charge the battery when connected to shore power.
3. The same as 2 above but run large gauge wires from the battery/alternator in my tow vehicle and charge with it while driving. (I did read the 13+ page discussion on towing while driving; learned a lot about how much I don't know )
4. Install a pure sine wave inverter close to the alternator in my tow vehicle and run AC wire to the trailer (through a connector) to run the fridge while driving.

If any of you have any experience or comments to share on any of the above options, it would be greatly appreciated. Also, if there are any other options I should consider, please let me know.

Best regards,
Kevin

[H.A.]

If you dont put a battery onboard, You will be better off fitting that inverter under you hood or otherwise inside adjacent to truck battery. Then use 120V cord to connect trailer & fridge to the inverter.
For bonus points,
Fit a relay so the inverter follows the on-off of ignition, or use a method of low voltage disconnect on inverters supply leads.

[edgeau]

Really? Running AC from the Tow vehicle seems kinda dangerous to me.
Also pure sine wave is important for sensitive electronics but for a fridge may be Overkill.


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[Philip]

Any starter/ alt rebuild shop can tap your alt for 110 volts. Find the amps on the fridge your going to use. Then talk to a shop and find out how many amps of A/C your alt can supply. Check price between both options. Pick the cheapest.

[H.A.]

Any starter/ alt rebuild shop can tap your alt for 110 volts. Find the amps on the fridge your going to use. Then talk to a shop and find out how many amps of A/C your alt can supply. Check price between both options. Pick the cheapest.

Ha Ha !
That's funny !

They might be able to get 120VAC 60Hz out of an alternator, But the instant its RPM changes it wont stay at that voltage or maintain frequency.

[edgeau]

For option 1 fill some milk or juice bottles with water and freeze before the trip. No mess and you have cold water to drink once you arrive.

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[kmack67.km]

Thanks for the suggestions. The milk jugs are a good idea for option 1 and I will likely start with that. I am still trying to decide if I can live without a marine battery in the trailer (for things other than the fridge). If I decide not to include the battery, that leaves option 1 or 4. What is the safety concern with running 120 VAC from the tow vehicle (other than the obvious hazard of higher voltage)? If I went with that option, I would use wet area rated heavy duty extension cord.

Best regards,
Kevin

[Shadow Catcher]

Do the math, Run 12V from the TV battery of sufficient gauge to the inverter and to the fridge.

[nemoskull]

not really sure what you asking since im still asleep.
if you want to run a fridge while in transit, using power from the TV to the trailer house battery charger is the first step. make sure to get a disconect.
i wan able to run a 1.1 cuft fridge on a walmart square wave (well, mostly square wave) 750w inverter. square wave will be fine, giving the lack of any silicon based electronincs in the fridge.
mostly just buy and try. the startup draw is what will be your problem. figuere 4x running.
if you cant start the fridge, you can install hard star capacitors. or just get a bigger inverter.

even assuming 100w draw, at 14v (car running) were looking at 16 gauge wiring. tho id really go: car > LV disconnect > charger > battery > inverter > fridge
the advange here is you can spider in solar or charge converter with out much problem.

or you could go solar > charger controler > battery > inverter > fridge
here its a set and forget, assuming you have enough solar. (i used almost all of my single 100w panel to run my 1.1 cuft fridge convertered to ice chest. about 14-24wh)

[H.A.]

i wan able to run a 1.1 cuft fridge on a walmart square wave (well, mostly square wave) 750w inverter. square wave will be fine, giving the lack of any silicon based electronincs in the fridge.

That probably work, But dont be surprised if the 'fridge dies early.
Nevermind lack of electronics, induction motors dont like running on 'squarewave'. They run at less torque and hotter than if powered by sinewave. May suffer slow starting too.

[Squigie]

Stick a wind turbine on the roof.

[edgeau]

Check the law where you live. Where I am DIY wiring of high voltage AC is illegal. You need a licensed electrician. But that might be because our mains are 240v.

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[GTS225]

Check the law where you live. Where I am DIY wiring of high voltage AC is illegal. You need a licensed electrician. But that might be because our mains are 240v.

***********************************************************************************************

Laws concerning DIY of electrical circuits are determined by our state's legislature.
The last sentence quoted above is key in this discussion, as the U.S. is one of perhaps a handful of countries that run 120VAC as a standard household voltage. Most of the rest of the world operates on 240VAC, 50 hertz power.
What's interesting about the above quote is that Aussie laws are most likely in place to protect the citizen, whether it's the DIY'er, or the next guy to own the house. The problem is, that 120VAC kills more people than 240VAC. The reason is that 120 doesn't cause muscle contractions violent enough to break one's contact with the energized wire or circuit, while 240 and higher will do just that. The "victim" might wake up hurting in places they didn't know existed, due to the "shock therapy", but the chances of at least waking up are much improved over an electrocution on 120VAC.
A bit of irony there, if one reads it that way.

Roger