Charging & running Fridge on 12v frm TV

John_and_Kris

I searched the section but can't find my answer. We have a Lexus 2015GX460 with Tow Pck including a 150amp Alternator. I would like the TV to charge the T@B battery and run the Fridge on 12volt. Question: will it work?

ScottG

John and Kris, here are my impressions, gained from various discussion here, as well as personal experience:

You didn't indicate which fridge model you have...

- If you are referring to the 3-way fridge (in the non CS models), the 12V setting draws a lot of power and will quickly deplete your battery. It's primary use is for running the fridge while towing. Even then, some alternators have a hard time keeping up (though you might be ok with your 150amp). When parked, propane is a much better option for running the fridge--it uses very little gas and very little battery power.

- If you are referring to the 2-way fridge (in the CS models) where propane is not an option, I understand they operate differently and draw far less power on 12V than the 3-way models. Maybe somebody with experience with this model can advise you on how long it will run on a battery charge.

That said...

- Your TV is an inefficient battery charger. I suspect you would do better with a solar panel, or a small generator. (And that's another thread all together!)

Nomad

As ScottG mentions - Your 150 alt should do fine for running the fridge while traveling, mine does. As far as charging you T@B battery, I've done it in emergencies but as Scott says, it's not real efficient. Solar's much better.

John_and_Kris

Thanks much Scott and PXlated. We have the 3way and would only be using the 12volt while traveling  and would hope it would also help the T@B a bit

ChanW

I found that my Tacoma (no tow package) had a hard time recharging a low battery at the same time it was powering the three way fridge.

The dumb thing about the three-way is that it runs continuously when in 12-volt mode - it pays no attention to the temperature setting.

YMMV, I think.

Nomad

ChanW - Really, that's stupid.

ChanW

Yes PXL, stoopid.

There is a mod for the three-way, which makes it recognise the temperature setting when in 12V mode, which allows it to switch off when it reaches temperature, just as it does in propane or 120V modes. Info can be found in the Yahoo group's Files section.
CORRECTION: my mistake, it's not in the Yahoo group Files, it's here: http://webs.lanset.com/rcochran/norcoldthermo.html

I've installed it on our fridge, but it's not a simple installation. You'd need to be comfortable with electrical circuits and wiring. It's not difficult to do, but a little knowledge helps.

Ratkity

Wow Chan, I didn't know that about the 3-way (in another context, that would sound bad lol.... ).

I just do what boo does minus putting frig on 12V. Cold food to start off with and a square water container that is frozen. I've driven 6 hours without any significant melting of frozen jug. Thermometers I have set up indicate 39-40F (where a frig should be) at the end of the drive. I put paper towels under the frozen water jug because it will sweat and the ice on the outside of it will melt off (this jug has been a fixture in my freezer for a while - used it several seasons prior to T@B-Life and it fits perfect in a 5-day Coleman cooler). It's an older jug, so I can't be sure there's no BPA in the plastic. I wouldn't want to drink water that has been frozen-thawed multiple times in such a container unless I'm lost in the desert and there's nothing else to drink.

ChanW

Frozen water jugs - that's what we've done, too, and then we use our standard Coleman cooler as supplemental in the back of the truck.

We haven't really come up with the perfect system yet. The cooler's a pain after a few days, because everything's piled up in there.

A vertical cooler would be easier to keep organized. Will have to look into that. B-)

Verna

I kept two 1/2 gallon milk jugs frozen for three months while I wintered in Arizona. Actually for about 2 1/2 months because either the plastic deteriorated or the wire shelving and the rough roads sliced the sides of the jigs. So I replaced the jugs, froze them in the ARB and put the new ones in the fridge. I have never run the fridge on 12V, relying just on the frozen water jugs and the frudge's insulation. 

Photomom

That reminds me, I seem to recall someone having a remote fridge thermometer - you didn't have to open the door to check the temp. Search hasn't found it - does this ring a bell for anyone?

Verna

Photomom said:

That reminds me, I seem to recall someone having a remote fridge thermometer - you didn't have to open the door to check the temp. Search hasn't found it - does this ring a bell for anyone?

Photomom, you can get just a remote thermometer (an indoor/outdoor one), place the outdoor one in the fridge, the main unit in the cabin. 

Ratkity

Photomom, have one that is indoor-outdoor and humidity. The "outdoor" probe goes into the frig and the "indoor" temp is the temp inside the room. Humidity reading is a bonus. Got it from Radio Shack I think.

Verna

Ratkity said:

Photomom, have one that is indoor-outdoor and humidity. The "outdoor" probe goes into the frig and the "indoor" temp is the temp inside the room. Humidity reading is a bonus. Got it from Radio Shack I think.

I just bought one from Walmart with the humidity. Since it was for the house (not T@B), I bought a larger one. 

Ratkity

What I love about the off-the-counter one as opposed to one made for the frig (there are ones made for them), is that the display is LARGE lol. I have the display velcro'd to the wall and it hasn't moved when traveling. The probe cord follows the wall and goes inside the frig on the hinge side. The cord is tucked out of the way inside the frig (other side of the fins).

Photomom

Ratkity said:

What I love about the off-the-counter one as opposed to one made for the frig (there are ones made for them), is that the display is LARGE lol. I have the display velcro'd to the wall and it hasn't moved when traveling. The probe cord follows the wall and goes inside the frig on the hinge side. The cord is tucked out of the way inside the frig (other side of the fins).

I was thinking you'd need a wireless one to keep the fridge sealed up.

JiroTX

I didn't know about 12v mode on the 3way fridge either. It makes sense now that the temp kept dropping while traveling. I have one of those wireless thermostats and kept the display in the TV. I had to turn it off several times during the 13hr drive because the temp was dropping to 27 and sometimes below.
I usually freeze some meat and put it in a cooler box with some dry ice in it. They stay frozen for a couple of days with a cheap styrofoam cooler box.

ChanW

Yeah, it works pretty good as a freezer that way!

ChanW

Yeah, the mod uses a relay.

johnsonjean

I have clamshell model with 12 volt refrigerator.  I have solar but battery doesn't keep refer running all night.  will be installing 2 6 v golf batteries.  does anyone know if this will do it to keep refer running all night?

Nomad

"if it ran 100% of the time" is the key phrase <- In practice, how long does it run typically?

jkjenn

johnsonjean said:

I have clamshell model with 12 volt refrigerator.  I have solar but battery doesn't keep refer running all night.  will be installing 2 6 v golf batteries.  does anyone know if this will do it to keep refer running all night?

There are some who have done this. I would check the FB or Yahoo groups. 

Nomad

So, if 25% of the time it would only be 10 amp hours over 10 out of 50. Won't kill the battery at that rate or almost twice that. Probably a bad battery. What do ya think Bob?
If you want dual 6s, that's fine but it shouldn't be necessary.

mash2

I was led to believe that the characteristics of norcold 2-way are similar to earlier Engel's.  Performance data for this are attached..  Chart shows range of AMPS required at various ambient temperatures and desired frig temperature.  

webcrawler

I have towed with norcold on 12v for several hours at a time with my Lincoln MKC with no issues...  It does have a 12v charge line.  It also powers the wireless brake controller.

I suspect the power demands of the 3way might have been exaggerated over time...

Nomad

Webcrawler - Appears to depend somewhat on your TV alternator - Mine came with a large alternator as part of the factory tow package and dies ok while others struggle.

ChanW

I've measured the power draw on the 3 way fridge. It's approx 11A, continuous. It doesn't switch on and off with the thermostat.

I'm pretty sure I didn't have my Fluke DMM's "Exaggerate" switch on, when I measured it... B-)

webcrawler said:

I have towed with norcold on 12v for several hours at a time with my Lincoln MKC with no issues...  It does have a 12v charge line.  It also powers the wireless brake controller.

I suspect the power demands of the 3way might have been exaggerated over time...

keithp

ChanW said:

I've measured the power draw on the 3 way fridge. It's approx 11A, continuous. It doesn't switch on and off with the thermostat.

The 12V heater is 'always on' as it isn't wired through the thermostat. It might be that the thermostat can't handle that much current? I've heard a rumor that someone came up with a fix that added a relay into the circuit; anyone got a link for that?

ChanW

Edited... keithp, i mentioned that mod at the beginning of this thread, but I can't find it in the Yahoo files now B-)

Edit again: my mistake, it's not in the Yahoo group Files, it's here: http://webs.lanset.com/rcochran/norcoldthermo.html

(Well, we've successfully talked ourselves around in a circle now...)

Ratkity

Don't worry, Chan. I rabbited-holed the last leveler thread in so many turns that everyone got dizzy who read it.

keithp

ChanW said:

http://webs.lanset.com/rcochran/norcoldthermo.html

I've ordered parts to do something similar. I think I can avoid the constant current draw mentioned in that post; if so, I'll write it up and post it here.