TV charge line, inverter, and running a fridge

[ependydad]

I have a little dorm fridge in my outdoor kitchen (no idea on brand, but it's something like this- random dorm fridge on Amazon). While we are going down the road, this thing loses heat like my daughter loses sunglasses: quickly and often.

I'm only running a single battery in my setup - a Trojan TMH27. My thought is to install a large-ish pure sign wave inverter. And then install a 120v outlet off of the inverter back in the outdoor kitchen. When we have longer driving days, I'd switch the fridge to run off of the invertered outlet.

My concern is- I know there is some charging of the battery from the TV. I don't know how much. Nor do I know if it is enough to overcome the draw from this dorm fridge (with the inverter).

It's not incredibly often, but we do fairly regularly stop for overnight stops without hookups. I'd like to make sure that my battery isn't being depleted during a day of driving and then be unable to support our overnight power needs (generally just my sleep machine and occasionally the furnace).

Being able to push some charge into it over a day of driving would be ideal (while it's SUPER RARE, we do sometimes do back to back overnights without hookups).

Does anyone know if this idea will work?

[retiredcamper47]

Have you ever considered using a piece of dry ice in your fridge? It will definately keep things cold and will not melt like regular ice. A 1 lb piece will last you 3 or 4 days easy. Just have to be careful and not touch it with your bare hands. When I used this method, the dry ice came wrapped in newspaper. I would get it at a local ice house. This would save you the $$ and hassle of wiring and pieces & parts. Just a thought.....................

Bob

[ependydad]

Originally Posted by retiredcamper47

Have you ever considered using a piece of dry ice in your fridge? It will definately keep things cold and will not melt like regular ice. A 1 lb piece will last you 3 or 4 days easy. Just have to be careful and not touch it with your bare hands. When I used this method, the dry ice came wrapped in newspaper. I would get it at a local ice house. This would save you the $$ and hassle of wiring and pieces & parts. Just a thought.....................

Bob, that's an interesting thought. I need the inverter anyway because we're getting a sleep number bed and will need the ability to inflate/deflate the beds when we change altitudes. So, the extra expense should be marginal to run the line back to the outdoor fridge.

We also travel a lot (full time) and I wonder/worry about the hassle of finding dry ice on a regular basis.

[mlatter]

This is impossible to answer without knowing the requirements of the fridge, and more importantly, the gauge of the wire from your TV alternator to the trailer.
I have a 3000 watt sine wave inverter with 4 6v batteries in the trailer and a 320 amp alternator in the truck. Also, I have a separate connection from the alternator to the trailer using heavy gauge welding cable, with a disconnect in the bed of the truck. I can run the 13,500 BTU bedroom A/C all day while driving. (kitties riding in the trailer)
The moral of the story is that you need a good (heavy gauge) connection from the alternator to the trailer batteries to ensure sufficient current flow while driving.

[ependydad]

Do you have any more details on the separate wire from the alternator? With my truck, I got the snow plow package, so it has a beefed up alternator. But, I really don't know what that does for me.

I don't have anything fancy with regards to the trailer plug-in at the truck. It's fairly standard (it's an aftermarket in-truck bed outlet but it's just tapped off of the bumper plug-in).

[mlatter]

I ran my own welding cable from the alternator to the front of the truck bed, and of course ground as well. I then fed the same heavy gauge cable through the fifth-wheel pinbox on the trailer, down to connect to the trailer battery bank.
I put a welding connector on the ends of the wires in the truck bed to be able to connect and disconnect as necessary. It ended up being a couple of feet of the cable + connector on the trailer end, and the same on the truck end.

This is all to provide a heavy gauge connection from the alternator to the trailer batteries, or battery. That is the key - to provide an easy path for the voltage from the alternator to be able to reach the trailer battery. (thin wire = voltage loss)

Since you won't be running an A/C while driving, just a fridge, you will be able to get by on a much smaller gauge wire. I'd estimate 12 gauge wire would run your inverter and fridge, but I think the gauge that comes standard is more in the 16-18 range.

[Kenny kustom]

I plan on doing the same.

I live in a fishing town. Lots of ice fishing.
They use those big old bombardiers on the ice.
I have set up quite a few car haulers to transport them.

I put a deep cycle batt in a box on the trailer. Winch on the trailer to the battery.
I run a pair of 4ga from the under hood battery to the bumper, with a disconnect.
Another pair from the trailer battery to the bumper disconnect.

I'll use 8 ga from my truck battery to the bed, and feed a pair through the nose to the rv battery bank.

That should give decent current while travelling.


2016 Sabre 36QBOK
2015 Ram 3500 CUMMINS

[Bluepill]

Re the inverter size. I assume that the reefer is NOT frost free. You should be fine with an inverter rated at 400 watts, 800 surge. Your reefer probably uses less than 200 watts running, maybe 700 at startup.

Nothing wrong with going bigger. That gives you options for the future.

For the use you mention, a 30 amp. connection between the TV and the trailer would be sufficient, unless you plan to use the line to recharge a discharged battery in the trailer. Then a 50 amp line would be good. You would want an HD connector like this:

http://www.amazon.com/Tuff-Stuff-Win.../dp/B002CEPI5O

[mlatter]

I forgot to mention, I used 2 gauge cable and these connectors:

Connector

And even those cables get warm when running the air conditioning in the trailer all day.

[Kenny kustom]

I know this is Lazarus...
But Doug, my inverter powers almost the whole coach, no need to run wires all the way back. Just tie into a few circuits from the main panel.

I used four. That includes one main second ac. So, three other ones powers almost everything.

I run both fridges ( on ac) while on the road.


2016 Sabre 36QBOK
2015 Ram 3500 CUMMINS