Battery Cable Butt Connectors

[jleonard]

Were I used to work as an engineer we used Molex connectors and had crimp machines. I had to teach operators how to inspect their work so I got the guide (because I didn't know squat about it).
I have a copy of their crimping guide which had some nice illustrations of what good and bad crimps look like.
While I do not really want to post it here I will send the file to anyone interested .
They only go up to size 8 wire but the principles are still the same.
Send me your e mail addy in a PM if interested.

 

[CharlieJ]

@Barking Sands #54

The better crimp is the box crimp whereas the crimping dies are either hexagonal or are round in shape. This type of crimping die produces much more uniform contact area in the ring terminal barrel. The 12 ton quality built (not an eBay knock off), hydraulic crimper that I use compresses the tinned wire so tightly that I cannot see the interstitials between the individual strands with the naked eye.

Regarding welding cable:
1. I have removed many, many feet of failed welding cable from 80's vintage Chinese and Taiwanese built boats.
2. For those of you that care about the voluntaryABYC Standards and the liability the equipment installer assumes by not adhering to these minimum standards, here is an excerpt from the ABYC Electrical Standard:
11.14.1.2.1. Conductors and flexible cords shall have a minimum rating of the nominal system voltage.
11.14.1.2.1.1 The construction of insulated cables and conductors shall conform with the requirements of:
11.14.1.2.1.1.1 UL 1426, Cables for Boats, or
11.14.1.2.1.1.2 the insulating material temperature rating requirements of:
11.14.1.2.1.1.2.1 SAE J378, Marine Engine Wiring, and
11.14.1.2.1.1.2.2 SAE J1127, Battery Cable, or SAE J1128, Low-Tension Primary Cable.

Welding cable does not meet any of these requirements save for the voltage limit. UL 1426 Boat Cable meets all of these requirements.

As I tell my clients, IYB (It's Your Boat.)

 

[FlyWright]

I broke the tinned cable cardinal rule when I rebuilt the big cable supply side of my electrical system years ago. I had access to a discarded aviation grade ground power unit (GPU) cable that had the insulation sliced into at the mount. It's capable of starting jets with hair thin wires in a cable capable of carrying 5000A at 30V. Under FAA rules, the part could not be repaired; it had to be replaced.



OK, maybe it's a bit overkill for a 34 footer but I have next to no voltage drop in my cables...

 

[psneeld]

Proper cable standards are a good idea

Tinned wire/cables can be debated.

Pay what you want, think of just what you really need....or as many say....for a little more you get xxx.

 

[Barking Sands]

@Barking Sands #54

The better crimp is the box crimp whereas the crimping dies are either hexagonal or are round in shape. This type of crimping die produces much more uniform contact area in the ring terminal barrel. The 12 ton quality built (not an eBay knock off), hydraulic crimper that I use compresses the tinned wire so tightly that I cannot see the interstitials between the individual strands with the naked eye.

I agree. To properly do large cable you need some very good equipment, the right process and compatible parts/tooling/wire and a means of testing. In my 35 years as an aircraft tech I have seen the best of the best crimps still fail with time. I am not anti crimp though. I would probably make the connections the OP was asking about. But I would just caution that you need a plan for that size cable. Its VERY difficult for average Joe's to make that crimp properly.

I have picture after picture of failed crimps on large wires on aircraft. Some of these were very difficult to troubleshoot and some were near catastrophic.

As a side note...we use crimps in the field for smaller wires and we still use solder connections as well. I am sure I have crimped thousands of wires and soldered just as many. But we no longer make large wires in the field due the the unreliability of the process and liability concerns. If you notice the short failed wire in the pictures, it has a part number and was made by people who specialize in wire manufacturing. I had some other pictures from a failed ground crimp that damaged the surrounding aluminum fuselage structure that were just terrible. Ill have to find those.

 

[Brent Hodges]

As for the OP's original question, I think the latching relay type of remote battery switch is a much better solution than extending the cables. I've done that several times, including on my own boat, and it just makes sense. Doesn't add more cable run to high amperage circuits, and makes a very clean switch panel. A lot of new boat builders now use these.
The other comment I'll reply to is this, Welding Cable has NO PLACE on a boat! I don't care how cheap it it! It's not just the fact that it's not tinned, or that the extremely fine wires will wick moisture like a candle wick, but the insulation will not hold up! Like Charlie said, I've pulled a ton of welding cable out of older trawlers (even Kady Krogen used it in the early 80's) where the insulation was literally falling off of the wire. Don't ever use welding cable in a boat!

 

[Frank Tew]

Have you considered a Blue Sea #ML-RBS Remote Battery Switch, 500amp disconnect? I installed one Saturday for my bow thruster and windless. It works great with a console mounted switch or you can manually operate it from the engine room. my solution to not having to enter the engine room every time I need to operate these options.

 

[Tom.B]

Have you considered a Blue Sea #ML-RBS Remote Battery Switch, 500amp disconnect? I installed one Saturday for my bow thruster and windless. It works great with a console mounted switch or you can manually operate it from the engine room. my solution to not having to enter the engine room every time I need to operate these options.

One of the underlying issues is that I would need at least two, but probably four to switch my rig (because they don’t make a 1/2/off/both version). At $200 a pop, I might as well just replace all the cable lengths. I am trying to avoid that, not only because it would be a huge PITA, but the price of wire is it the clouds. While I don’t want to compromise safety (much), I also don’t want this to take several weeks to complete.

 

[seabreez]

Rather curious how batteries are safer in a living space? Especially when cables would exist in both.

In Canada... batteries are not allowed in a passenger compartment... whether it be in a wheel house, pilot house or living space. The batteries have to be in an engine room with proper ventilation and emergency batteries have to be outside, in a locker, vented and a with a main fuse.

 

[RT Firefly]

Greetings,
Welcome aboard eh?

 

[ORIF]

One of the underlying issues is that I would need at least two, but probably four to switch my rig (because they don’t make a 1/2/off/both version). At $200 a pop, I might as well just replace all the cable lengths. I am trying to avoid that, not only because it would be a huge PITA, but the price of wire is it the clouds. While I don’t want to compromise safety (much), I also don’t want this to take several weeks to complete.

I think you said you have shore runs for this project.
Pacer has 2/0 cable that you can buy by the foot.
About $6/foot and would eliminate the need for any interval connector/potential failure point

https://www.pacergroup.net/products/cable/marine-battery-cable/

 

[ORIF]

Never mind, reread your post.
Pacer makes quality cable though.

 

[dutch-barge]

why not use remote battery switches....I use them on both my boats...Blueseas systems

 

[BDofMSP]

Mr DB,
If you go back and read the thread, adding remote battery switches is exactly what the OP is doing here.

 

[rolomart3]

I am planning another electrical system upgrade, including moving the battery switches out of the engine room and up to the living space for better access (safer too). I have seven or eight wires to move about two or three feet up to the new location, however, some of these wires and 0/2 gauge and are already kinda long and secured into some tight places. It would be a TON cheaper and a TON easier to use butt connectors to tack a few more feet onto the end to get the to reach their final destination. Assuming I make properly crimped connections, is there any significant line loss that would have me reconsider?
View attachment 98542
View attachment 98543

There should be no problem. A good idea after the butt connector of the red wire is crimped is to practically bath the connector in silicon grease an then shrink grap it. This way there is no need to worry if the wire accidentally is submerged in the bilge. To avoid induced stray current corrosion it is desirable to prevent at all times positive voltages in contact with water.
Rolo

 

[Tom.B]

Mr DB,
If you go back and read the thread, adding remote battery switches is exactly what the OP is doing here.

Not going to remote switches... this is a RELOCATION of existing ones.

 

[Tom.B]

why not use remote battery switches....I use them on both my boats...Blueseas systems

Expense mainly... plus they don't have 1/2/both/off options.

 

[Tom.B]

In Canada... batteries are not allowed in a passenger compartment... whether it be in a wheel house, pilot house or living space. The batteries have to be in an engine room with proper ventilation and emergency batteries have to be outside, in a locker, vented and a with a main fuse.

I am NOT planning on relocating the batteries. Only the switches, charging, and some fusing.

 

[CMS]

Regarding welding cable:
1. I have removed many, many feet of failed welding cable from 80's vintage Chinese and Taiwanese built boats.

Same here...

 

[castellah22]

Not a problem put in a junction box and rewire to your old switch, at a position in your in your boat, good luck.