Which wire to use?

[Wrecit]

After way to many starts and stops I am at the point where I am going to start wiring the Anti-stealth ctc.

The plan is to run a hybrid system based on a 100-200ah lifepo4 battery with a charger hooked up to charge during the day using a generator. (Yea solar is down the road but that's a "please honey can I have the money" discussion for later)
From charger to battery I will be running heavy wire (thinking around 6 gage). I will be running standard 12v wire from my Nilight switch panel to all my fixtures.

My question is what to run from battery to the Nilight panel. I happen to have about 15 ft of standard 3 wire 110 house wire. My thinking is less resistance running to the switch panel should mean cooler temps.

Ok experts tell me everywhere I am going to make mistakes lol

[tony.latham]

From charger to battery I will be running heavy wire (thinking around 6 gage).

It makes no sense to run that heavy of wire from a charger. Use the same gauge wire that the charger has. I'm guessing it's 12 AWG or much less.

I happen to have about 15 ft of standard 3 wire 110 house wire. My thinking is less resistance running to the switch panel should mean cooler temps.

I don't believe a camper should have solid wire. (And why 3 wires for a DC circuit??) I highly recommend copper-stranded. (Not copper-coated aluminum). The RV industry disagrees, but they sure build quality stuff...

This is the cable I would recommend for your DC stuff. It'll handle up to about 12 amps--probably more than your Nilite panel can handle. And using solid copper 12 or 14 gauge with that panel would drive me nuts.

https://www.amazon.com/gp/product/B074DMPH8P/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

Tony

[Wrecit]

Tony I'm curious about your reasoning behind stranded over solid copper wire.

[tony.latham]

Tony I'm curious about your reasoning behind stranded over solid copper wire.

I should have explained. Sold wire vibrates and hardens (work hardening). That's why stranded copper is used in aviation and marine applications.

Tony

[Hubert]

It's not just a question of wire gauge, but also the length of the run. There are online wire gauge calculators to figure out what size wire and fuse to use for your loads.

[philpom]

I used 8 gauge from my battery to the distribution panel and 10 gauge out to each "device". 30amp main breaker before the panel and each device has a dedicate fuse at it's location. I feel good about it and could push 10 amps through the 12v socket adapters without fear. Smaller would probably be ok but the extra cost was minimal and I tend to over build. I agree that 6 gauge from the charger seems extreme unless it's a 40amp charger and that would be extreme.

[bdosborn]

From charger to battery I will be running heavy wire (thinking around 6 gage).

It makes no sense to run that heavy of wire from a charger. Use the same gauge wire that the charger has. I'm guessing it's 12 AWG or much less.

A #12 is going to get pretty hot if he has a plug in RV charger that puts out 40 amps or more. My inverter/charger in the van will put out 80A. How big is the charger?
Bruce

[troubleScottie]

One possible chart:

[Wrecit]

Thanks all. A lot to consider and great info.

To answer a few questions. First the simple concerning using 3 wire house from battery to fuse panel. I got it laying around is the short answer. Just not planning on hooking up the ground.

The trailer won't be a real road warrior (3 20 to 30 mile trips a year) so the solid vs stranded wire issue is probably a non issue.

The charger says it draws 30 amps. As a carpenter by trade I believe in over killing my personal stuff because after spending 40 plus hours a week doing construction I don't want to spend evenings/weekends repairing/fixing stuff. Thinking maybe 8 gage would be the smallest I would feel comfortable with (still probably over kill)

[troubleScottie]

A note worth remembering.


B Find circuit LENGTH IN FEET along the left side of the chart. Note that the total length of the circuit is the roundtrip distance from power source (usually the battery) to the product and back.

[tony.latham]

The charger says it draws 30 amps.

Geeeeze! I couldn't plug that beast in here at the house.

Tony

[bdosborn]

The charger says it draws 30 amps.

Geeeeze! I couldn't plug that beast in here at the house.

Can you post the model number of your charger? I think it has a 30A output instead of 30A input. Tony's right, that's not a charger size you ever see for an RV - it would be around 300A output at 12V if it does draw 30A at 120V. The $1,200 victron chargers only output 120A at 12V.
A 300A charger would need a 4/0 cable to the battery.
Bruce

[RJ Howell]

Tony I'm curious about your reasoning behind stranded over solid copper wire.

I should have explained. Sold wire vibrates and hardens (work hardening). That's why stranded copper is used in aviation and marine applications.

Tony

There's quite a debate on this.. It's more of what (amperage over voltage) that matters. To say those applications prefer, over why they prefer..
In our case of short distance and low amperage, oe it really make a difference?
I have solid wire down to my well at home. Would I change out to twisted?
I've twisted solid wire in my build of conditioning batteries.
Ya, a reason for each, but...

Does it make any real difference in our usages?

I'm curious! Always open minded!

[tony.latham]

There's quite a debate on this.

I, too, have solid wire in my home (and down my well).

Here's from the Experimental Aircraft Association on aircraft wire. (Experimental aircraft can legally use anything.)

The most important consideration in wire selection is that the wire be made up of twisted wire strands... not a single solid wire core. Stranded wire stands up better under vibration and is less likely to break.

That's why I use and recommend stranded wires for campers that travel thousands of miles in their lifetime. It's probably the same reason you won't find solid copper wire in automobiles.

Yes, the RV industry gets away with solid wires, and I assume they do because they have lobbyists and a three-year guarantee.



Tony

[Tom&Shelly]

Tony I'm curious about your reasoning behind stranded over solid copper wire.

I should have explained. Sold wire vibrates and hardens (work hardening). That's why stranded copper is used in aviation and marine applications.

Tony

There's quite a debate on this.. It's more of what (amperage over voltage) that matters.

I'm curious! Always open minded!

With respect, I'm not sure why you think stranded vs solid wire has anything to do with voltage vs current (amperage). Or maybe I misunderstood your post. Stranded wire has to be a little larger than solid to carry a given current a certain distance. It has nothing to do with voltage at all (for the voltages we work with). This is straight forward electrical engineering and there is no debate (among those who understand it.)

As Tony says, stranded wire should be used wherever there is vibration or the likelihood of the wire moving. It won't move in your home, or in the ground down to your well. It will in any vehicle, from teardrop to spacecraft.

If one uses solid wire in their teardrop, they're asking for a break somewhere, probably where they can't access it. I'm saying the first part because I'm an electrical engineer who worked in the aerospace industry, the second part because of Murphy's Law (which all engineers respect.)

This is the first I've heard that commercial camper builders use solid wire. Frankly, that's just incompetent, which is just one more example of many I've heard of about that industry.

Use stranded wire! Whatever extra cost is minimal compared to the headaches you'll save yourself.

As far as wire size, I'd use the wire charts (for stranded wire), and try not to use larger than I had to. Larger costs more, sure, but more important it's much harder to work with, and you're liable to make poor connections that will break over time, leading to the headaches.

Tom