Refrig on battery or propane overnight?

[shunter917]

We are planning a 2 week trip in October. We will be spending one night in a hotel. I am wondering the best way to run the refer overnight while we are there.

I am concerned that running the refer (and fan) will drain the batteries (2 in line 6 volt - around 200 amp hours), since it will be parked 12 - 14 hours (about 5 pm to 7 am). I have thought about opening the TM just enough to switch the refer to propane, then closing it again. In the morning, I would open it and switch it back to 12V.

I am worried, though, that there won't be enough ventilation for the propane burner. I certainly don't want either too much heat to accumulate in the refer cabinet or for poor ventilation to cause the flame to go out, which would just allow propane to leak into the TM all nigh. And can I/should I shut off the fan while it's just sitting in the parking lot?

Any opinions appreciated.

[fcatwo]

We bought a 12V cooler to use when we will not be staying in the TM for any reason while traveling. We turn the fridge off and unload it before closing down that morning and take the cooler in the motel or friends house and plug it in there. It serves as a storage box in the back of the van otherwise. It won't keep things frozen for very long of course so a little pre planning is necessary to minimize the amount of frozen stuff on hand. Otherwise I would set the TM up and use propane or leave it on 12V and let the 6V batteries carry it as long as possible. It's insulated and should hold food for several hours without running and my understanding is that it doesn't hurt 6V batteries to be completely discharged.

Originally Posted by shunter917

I am concerned that running the refer (and fan) will drain the batteries (2 in line 6 volt - around 200 amp hours), since it will be parked 12 - 14 hours (about 5 pm to 7 am).

Keep in mind that the refer pulls +/- 10 amps on 12VDC. If you plan to use it overnight for 12-14 hours, you will just about drain the batteries to zero... not a good idea.

Originally Posted by shunter917

I am worried, though, that there won't be enough ventilation for the propane burner. And can I/should I shut off the fan while it's just sitting in the parking lot?

I recommend you open the trailer, switch to propane, leave the fan running to dissipate the heat. You could leave the trailer up (& lock it up) or fold it down, either way the flame doesn't generate that much heat and the fan is designed to keep the trailer and back of the refer properly ventilated.

[mjlaupp]

I tested my 2 6v golf cart batteries for fridge run time. At 6 hours, I had depleted them to half charge. So the most you could expect would be 8 - 10 hours of usefull power. Then you would be trying to re-cool the fridge and recharge the batteries at the same time using the "excess current" from your tow vehicle alternator.

I would open the TM and turn the fridge and fan off. Don't open the fridge and it will hold the cold overnight. The only casuality might be the ice cream getting soft. You can help it to retain the cold by freezing several bottles of water and keeping them in the freezer while you are overnighting. October nights should be rather cool and that should help.

I would not run the fridge on gas with the TM closed. If the fan stopped for any reason, you could end up with heat damage or even a fire.

MJL

[Bill]

Strange as it may seem, the refrig operates from a heat source. When you change the front panel switch, you just change which heat source you are using. The three heaters in the refrig - 12 VDC, 120 VAC, and propane - all generate about the same amount of heat. If you feel comfortable running the refrig on one of the electric heaters when the TM is closed, you should feel just as comfortable running it on propane.

Incidentally, I would turn on the fan regardless of which heat source you are using. By removing the waste heat from the compartment behind the refrig, you make it run more efficiently - which in turn will minimize the amount of time that the heat source is actually turned on. The fan draws very little current.

Mike's suggestions about keeping the refrig door closed and freezing bottles of water or blue ice packs are good ones.

Bill