Reddit mentions: The best boat electric wires

Thank you all for the constructive comments! I apologize for having confusing information. It even took me a minute to compile it with what I thought to be an understandable manner because it even confuses me if I don't go through it in one breath. I'm going to do my best to clear things up.

u/velaazul , Here is a schematic I drew. - http://imgur.com/a/Zldos
Not the best drawing but I did it as I pieced it together, I could try to do another to clean it up a bit.

HouseBatt is the car battery. Batt1/Batt2 are deep cycle batteries. Currently this draft is a two 12v deep cycle battery operation. I still need to spend some time calculating (and understanding) what my daily/weekly power consumption would look like to see if two batteries will be sufficient for my lifestyle. I'm also trying to figure out how long I will have to run my car to charge these.

I don't necessarily plan on doing this under my current build for more than a year so there is room for improvement beyond this. With that said I know it may not be the most efficient setup possible, but I need to get my feet moving forward and make this happen.

Fuses are something I am conflicted about. I've seen instructionals that incorporate fuses, and I've seen builds that don't. I've heard people say you need them and heard people tell me I don't. If I do indeed need fuses put in place I would put a fuse between the Small Solenoid terminal to the alternator. and the 2nd fuse would be from the House Battery positive wire to the Deep Cycle Battery 2.

u/Y_BOT , am I misunderstanding the function of the solenoid? From what I understood it would function independently and control the flow of electricity from the alternator to the car battery and then to the deep cycle. When I turn the key in the car that should activate the solenoid switch to charge my car battery and deep cycle. When I draw power from the deep cycle the solenoid should act as the barrier between the deep cycle and the car battery so I never drain my cars battery when using the deep cycles. In the schematic I drew I have included the solenoid and an alternative- an isolator switch. If possible I'd prefer to wire the solenoid so I don't have to manually disconnect batteries.

u/MythicalMover , I plan on purchasing 8 guage wire, however I have not purchased any of the materials yet. I have written out a list of necessary equipment for this project with rough cost estimates. I'm trying to square away my setup before I move forward with buying what I need. I plan on going to auto parts stores and Lowe's to browse wires, lugs, batteries, ect. Also you've hit on another point that I need to flesh out. That being the load capacity for the solenoid connected to my alternator and then potentially the fuses and their load capacities.

Every time I come back to work on all this power planning it alternates between seeming simpler than I previously thought to more complicated and back and forth between the two.


Again, thank you all for the direction and the help! I will also attach links to a few products I am looking at buying for this project. I use most of these as visual representations though. I want to go to a store to actually see and hold a tool before I buy it to ensure I feel right about what I need.

Might need these: https://www.amazon.com/Plated-Battery-Terminal-Positive-Nagative/dp/B00ORH1W2W/ref=sr_1_3?s=hi&ie=UTF8&qid=1486148779&sr=1-3&keywords=car+battery+terminal

This is the solenoid that I have in mind. https://www.amazon.com/gp/product/B0064MX7US/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B0064MX7US&linkCode=as2&tag=rvlifenetwork-20&linkId=TL56E2B62BVKAEKJ

2nd considered solenoid: https://www.amazon.com/Intellitec-Battery-Disconnect-Relay-Prevents-Batteries/dp/B00KPR8QAO/ref=pd_bxgy_263_img_2?_encoding=UTF8&psc=1&refRID=4S939F2G73BZBDQ6JZA9

Inverter (though I might up it if I need more watt handling if need be): https://www.amazon.com/Cobra-400-Watt-12-Volt-120-Volt-Inverter/dp/B001RNOHBC/ref=sr_1_7?m=A2VVWG2KXGK6N2&s=merchant-items&ie=UTF8&qid=1485455953&sr=1-7

Deep cycle battery consideration: https://www.batteriesplus.com/battery/marine-and-boat/deep-cycle/bci-group-27m/sli27mdc

8 guage wire: https://www.amazon.com/Ancor-Marine-Grade-Duplex-Cables/dp/B000NV0BNM/ref=sr_1_1?s=sporting-goods&ie=UTF8&qid=1486225382&sr=1-1&keywords=8+gauge+wire

(optional) Isolator switch: https://www.amazon.com/Marine-Battery-Disconnect-Switch-Isolator/dp/B00EBQOKEQ/ref=sr_1_2?s=sporting-goods&ie=UTF8&qid=1486225429&sr=1-2&keywords=isolator+switch

I also intend to protect my wires with conduits. If necessary I will need to buy lugs and shrink insulation to "make" my own wires for this project. Crimping is something I would imagine I could find a friend to help with or get done at a store.

Hopefully I covered everything, let me know if I am still missing any information and again sorry this was all not included in my original post!

1. Wire wise - Amazon - look up Anchor Tinned Wire and get a 25' section of 8ga 2 wire red/black at biggest (radio, plus lights, plus accessories ) but 12ga with 2 wires should be fine for small electronics.
   
   
   Example:
   
   https://www.amazon.com/Ancor-121510-Marine-Duplex-Cables/dp/B000NUYBW0/
   
   
2. Lack of a Switch or Disconnect - don't do this. A) Danger Will Robinson ! B) is not approved by coasties/inspection most places. Get a proper battery switch. Put this switch between the battery Positive and the motor positive and your accessories positive. The ground/black from the motor, from the accessories etc can all go right to the negative terminal on the battery. We're only switching the 12+ Positive side.
   
   
   Example:
   
   
   https://www.amazon.com/Perko-8501DP-Marine-Battery-Selector/dp/B00144B6AE
   
   
   
   
   I say these things for the following reasons:
   
   
3. you'll eventually wanna sell the boat and upgrade to something bigger. When I as a buyer see things like accessory wiring going right to the battery instead of a battery switch - I use items like that to lowball the fuck out of the seller. It also says "if they did this janky to save $20, what else did they do janky" ?
   
   
   
4. Safety - you always need a way to 100% disconnect electronics. This can be because of a fire, a mystery battery drain, long term storage etc. We want a disconnect from the battery. Now that said - plugging and unplugging a quick connect/ disconnect versus a proper battery switch is a GREAT way to blow yourself up depending where the gas fumes are, where your gas tank is, etc. It's one more possible thing to corrode as well as ignite. Make sure when you do your charging etc you are careful (connect the tender first THEN plug it into the wall outlet)
   
   
   
5. Long term usage - the more correct you do it now, the more money you save in the long run making small repairs later.
   
   
   
   Wiring Example:
   
   
   https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRrykWkGL7Y6N6zwAiDNcYPNvgQglOC4aJx0ntB9qn2Iv_INk1TUQ

Just some things to think about from someone who has never worked with romex cable and has no idea of the US electric code.

From experience if you cut it once, you or someone else will cut it again in the future. You might know where it is and remember from your mishap but others even after being warned won't have your experience and the same thing eventually will happen.

If you are not going to rerun the cable at a more robust way at the least you should dig and plant something like pavement bricks over the whole run of the cable. This would make someone stop and think before continuing digging with a pickaxe or running an earth tiller over it.

If you want to repair the cable there are some specialty repair kits for cable from cheap to very expensive. Depending how much you pay a kit will bring the cable as close to its former tensile strength and electric insulation. Go too cheap and moisture/water will eventually go in the connection which can corrode the terminal blocks and leak electricity to the surrounding area or between the cut cables.

I am from europe where round cables are the norm so don't really know about weatherizing something like a mostly flat romex cable so I can't recommend any commercial product. From what you have in Amazon the nearest I would get is something like this one, the gel would keep moisture/water out but there is very little tensile strengthening. For me electric insulation is very important as in my country everything is run after a RCD(GFCI) so any electrical leakage would trip it.

A DIY kit would be to get something like 2 watertight romex fittings and a waterproof junction box. Drill appropriate holes for the fittings and attach the fittings. Pass the cables, tighten them and do the electrical connections inside the box with some terminal blocks. Fill the box with some kind of electrical insulation gel and close it.

Whatever repair you do put at least something on top of the connection to protect it and mark it for future troubleshooting.

Yes, just a day sailor.

I found the book on Amazon so I'll definitely order it and give it a good read.

This wire is about $90 for 100ft of 12awg triplex wire.
https://www.amazon.com/Ancor-Marine-Grade-Duplex-Cables/dp/B000NV2AVS

And would a single 100Ah battery like this one be sufficient with a 50W solar panel for what I'm trying to do?
https://www.amazon.com/Universal-UB121000-45978-100AH-Cycle-Battery/dp/B00S1RT58C/

Everything's so professionally done and then the hole for the wires to pass through is covered in tape (doesn't look good). IMO rubber grommets should have been used.

Either THIS or
THIS

Ancor Marine makes tinned copper wire.