Rv fridges any good?

[Jon in AZ]

Originally Posted by gordon2

The good news is that a dorm fridge will work fine for the OP (Max) because instead of camping, he wants a camper to live in full time in his family's driveway. The bad news is he wants a camper to live in full time in his family's driveway.

Good catch, Gordon. I didn’t connect the two threads.

While a dorm fridge would work fine for driveway camping, ripping out a working 3-way fridge to make room for it will hurt resale value and its functionality as a camper in the future.

I full-timed in an RV in a park with hookups for 4 years. Ran the 2-way RV fridge on electric the whole time without issue other than having to fiddle with the settings more often than a home fridge.

My advice remains the same. Try it first before making any alterations.

[Borden]

Originally Posted by maxwolfman

I'm looking at purchasing a 13 foot scamp. I read online that the RV refrigerators in those is nothing more than a box to keep drinks cool. That it really doesn't work very well as far as a fridge. Anyone have experience with this? Could I replace it with a dorm refrigerator?

We have a 78 boler 1700 that has the original fridge is small 3 way unit. Still works fine had it serviced 2 years ago. Takes some time to get cold, fastest is the propane. When cold we will switch to 110v if available or when going to a new campsite 12v (12v is for travel only as it is a major battery drain). Only complaint is the freezer part is so small.

Maybe fridge size matters? I agree with Jon in AZ about trashing fridge.

Definitely gets cold as stated just takes time. Nephew has a new trailer and wish our freezer area was a lot bigger more like his fridge and freezer.

[David Tilston]

Originally Posted by Raz

That's the charge line resistance. The internal battery resistance does not come into play because you are measuring beyond it. As I said, draw the circuit and apply your DC circuit analysis. If you have questions my friend, send me a PM and I will be more than happy to answer them. Oh for 5 minutes in room and a chalk board. Old school . Raz

Raz, No offence, but I don't feel the need to draw anything. I have presented my reasoning, and calculations. If you think that I have missed something, please feel free to correct me. Include any drawings that you think relevant. Vague instructions to make a drawing doesn't tell me anything. No PM required, this is for the benefit of everyone.

I stand by my analysis that the 12 VDC heater in a 3 way fridge should work to keep the fridge cool, assuming that there is no problem with the wiring in either the tow vehicle, or the the trailer.

It should be noted that my calculations assume that the fridge is designed to run at 12 VDC, and the vehicle makes 14.4 VDC when running.

60' of number 10 wire is not the problem. However, it is possible that #14 is being used, so lets look at that scenario. #14 copper has a resistance of 2.525 ohms per 1000', or 0.1515 ohms in my example of a 30' separation, (60' of wire) between the TV battery and the battery / fridge in the trailer. This begins to approach the resistance of the heater in a 325 W fridge. Which I have not yet calculated:
R=V²/P = 144/325 = 0.443 ohms. The combined resistance of 0.1515 ohms and 0.443 ohms is 0.5945 ohms. Using a running voltage of 14.4 VDC, this would result in a current of 24.2 amps, (28.5 amps using #10 wire) The heat generated by the fridge heater would be:
P = I² * R = 24.2² * 0.443 = ~260 W, (359.8 W using #10 wire)
Not quite the intended 325 W, but this should still not leave the battery in the trailer at zero volts, as the voltage lost in the wire is:
V = I * R = 24.2 * 0.1515 = 3.67 VDC, (1.77 VDC using #10 wire)
This amounts to 14.4 VDC - 3.67 VDC = 10.73 VDC, (12.63 using #10 wire) at the trailer battery / fridge. Not good. The battery is basically dead, but the fridge should still be cold, ish.
The lesson here is that #14 is not large enough wire. If you plan to run your fridge on 12 VDC while traveling, I would pull the lead off of the positive terminal on the trailer battery.
Note: the currents using #10 wire are slightly higher than in my previous calculation as a result of using 14.4 VDC instead of 12 VDC as the source voltage. This also resulted in slightly too much power at the fridge heater.

As stated previously, the trailer plug / socket has not been evaluated. Though if there was a significant amount of resistance here, (other than an open circuit) I would expect it to get very hot, (do you smell something burning?).

[rudymart25]

Hi - I recently installed this 12v fridge in my Hunter a couple months ago and run it off batteries/solar. I love it. A buddy of mine recommended it when he installed one in his westy and I’m glad he did. It’s from a company called truckfridge and the low power consumption (33-40w when compressor is on) is exactly what I needed since I have a smaller 100ah battery bank. The fridge itself is pretty big and even has a small freezer compartment. Hope this helps.

https://truckfridge.com/products/tf65-12v