Connecting thick gauge cables

Submitted: Sunday, Aug 14, 2016 at 09:16
ThreadID: 133216 Views:4942 Replies:9 FollowUps:15
This Thread has been Archived
I have some 3B&S 25mm2 cable that I am using for a dual battery set up. The Redarc BCDC1240 I am using has 8B&S 9mm2 cable coming out of it for the connection. When I was in the US we had stepdown butt splice connectors that I would crimp and use for this but I cannot find them anywhere so I have 3 options. 1 - crimp together 2 butt slice sleeves and insert them into each other. 2 - solder the cables together by inter-twisting the wires and cover in heat shrink. 3 - crimp a lug on each cable and bolt them together. I have all of my own equipment hydraulic crimper, soldering iron etc. I am more interested in safety over money or a slight voltage drop. The cable run is only going 6-7 meters and the reason I am using 3B&S is because I have hundreds of meters of it for free.
Any other options, ides or suggestions would be appreciated.
Back Expand Un-Read 0 Moderator

Reply By: TomH - Sunday, Aug 14, 2016 at 09:33

Sunday, Aug 14, 2016 at 09:33
How about thesehttp://www.larpro.com.au/larpro/category/164
AnswerID: 603373

Follow Up By: Member - John - Sunday, Aug 14, 2016 at 16:56

Sunday, Aug 14, 2016 at 16:56
The link takes me to a "Data Base Error"
John and Jan

Lifetime Member
My Profile  My Position  Send Message

1
FollowupID: 873017

Reply By: Allan B (Member, SunCoast) - Sunday, Aug 14, 2016 at 10:17

Sunday, Aug 14, 2016 at 10:17
.
Hi Ricky,
Technically, there is nothing wrong with reducing the number of strands of the 25mm cable to permit it to fit a crimp sleeve sized to accept the 9mm cable from the Redarc charger. The reduced section of the 25mm cable still has the same current-carrying capacity as the 9mm and there would be immeasurable volt-drop over the centimetre of reduced cable.
Strip 1.5 cm of the 25mm cable then work around the cable with side cutters until it fits the crimp sleeve. Cover the entire sleeve and a couple of centimetres up each cable with heat shrink (maybe two layers) for a secure and neat junction. Somewhat tidier than lugs and bolts.
Cheers
Allan

Member
My Profile  My Blog  My Position  Send Message

AnswerID: 603378

Reply By: blue one - Sunday, Aug 14, 2016 at 10:32

Sunday, Aug 14, 2016 at 10:32
Solder & heat shrink is the go as it is the simple solution. Do it properly and no hot joints.

Cheers
AnswerID: 603379

Reply By: AeolusRicky - Sunday, Aug 14, 2016 at 11:17

Sunday, Aug 14, 2016 at 11:17
Thanks Guys. I think I will go with Allan as I prefer to crimp than solder, hot topic and I hope it does not start up any arguments :)

Cheers,
Ricky
AnswerID: 603382

Follow Up By: Allan B (Member, SunCoast) - Sunday, Aug 14, 2016 at 11:21

Sunday, Aug 14, 2016 at 11:21
Crimping is industry proven and easy with the correct equipment. Soldering is messy and difficult without skill and experience.
Cheers
Allan

Member
My Profile  My Blog  My Position  Send Message

1
FollowupID: 873003

Follow Up By: TomH - Sunday, Aug 14, 2016 at 11:39

Sunday, Aug 14, 2016 at 11:39
Get some of the ones in my link and you possibly wont need to cut anything
2
FollowupID: 873004

Follow Up By: Allan B (Member, SunCoast) - Sunday, Aug 14, 2016 at 11:58

Sunday, Aug 14, 2016 at 11:58
Tom, are you perhaps missing the point that Ricky is joining a 25mm2 cable to a 9mm2 cable? I cannot see anything designed to do that in your link and in fact I don't think such a crimp link is manufactured.
The alternative of soldering into butt links is most difficult, if not impossible, to do reliably.

Cheers
Allan

Member
My Profile  My Blog  My Position  Send Message

1
FollowupID: 873006

Follow Up By: AeolusRicky - Sunday, Aug 14, 2016 at 12:09

Sunday, Aug 14, 2016 at 12:09
Nice supplier Tom, I will be using these guys in the future. I have used step down connectors in the past but I think they may no be made anymore or are unavailable in bigger sizes. No worries, stripping the strands and sliding both cables into a 10mm2 sleeve is easy and effective. I prefer to crimp as there is less chance of air in between strands etc. My soldering skills are alright but certainly not up to pro standards. Thanks again for all of the suggestions.
0
FollowupID: 873007

Follow Up By: Ron N - Sunday, Aug 14, 2016 at 12:28

Sunday, Aug 14, 2016 at 12:28
At the risk of starting arguments, straight crimping is just fine, IF you can totally protect the joint from ingress of moisture, dust and road grime.

If you can't protect the joint 100% from the above, then soldering is the only way to go.

Using Scotchlocks or unprotected crimp connections is a recipe for failure of electrical current transmission, particularly where current transmission levels are low.

I personally hate any crimped wiring joins with a passion - as it seems to me, that half my life has been taken up with chasing up wiring connection failures - that could always be traced to dirty, verdigris-attacked, crimped connections!! GRRRR!!!

Cheers, Ron.
1
FollowupID: 873008

Follow Up By: Member - mark D18 - Sunday, Aug 14, 2016 at 13:09

Sunday, Aug 14, 2016 at 13:09
Ricky

For what it is worth , I would be sticking with Allan's Idea .

Cheers
2
FollowupID: 873010

Follow Up By: Allan B (Member, SunCoast) - Sunday, Aug 14, 2016 at 14:12

Sunday, Aug 14, 2016 at 14:12
.
Hi Ron,
I wouldn't dream of starting an argument with you. I would just say that there seem to be as many arguments in favour and against either crimp or solder. Each to his own!
Of course, crimping has become the electrical engineering standard if for no other reason than economy. But in reality, it is possible to control the quality of a crimped connection easier than a soldered one. Provided that the correct selection of crimp lug and crimping die is made then it is almost impossible to go wrong. Soldering however requires training, skill and experience to reliably make a sound joint, particularly in cable sizes above 16mm2.
On the issue of corrosion, both crimp and solder require sound protection from environmental attacks. The advent of glue-lined heatshrink was a blessing for the industry.
So, you solder your end and I'll crimp mine and I'll wait in the bar for you. lol
Cheers
Allan

Member
My Profile  My Blog  My Position  Send Message

2
FollowupID: 873012

Reply By: Bob R4 - Sunday, Aug 14, 2016 at 13:17

Sunday, Aug 14, 2016 at 13:17
Stripping some wire strands from the larger cable, crimping, and sealing with adhesive lined heat shrink, and then a second layer of the same heat shrink longer than the first layer would surely provide a good electrical connection, and good moisture exclusion.
I've never had an issue with any such connection in my experience, particularly in marine/boat situations, so surely must be more than adequate with auto applications.
Simple too.
Solder can sometime create hard points around the join which would be subject to possible fatigue.


Bob
AnswerID: 603384

Reply By: Nomadic Navara - Sunday, Aug 14, 2016 at 15:44

Sunday, Aug 14, 2016 at 15:44
Have a look at these. They are made for the job.
PeterD
Retired radio and electronics technician

Lifetime Member
My Profile  Send Message

AnswerID: 603387

Follow Up By: Member - John - Sunday, Aug 14, 2016 at 16:55

Sunday, Aug 14, 2016 at 16:55
Peter, that takes me to a "Data Base Error" same as the first link to the site.
John and Jan

Lifetime Member
My Profile  My Position  Send Message

0
FollowupID: 873016

Follow Up By: Member - Roachie - Sunday, Aug 14, 2016 at 16:59

Sunday, Aug 14, 2016 at 16:59
All I get is their website and "DATA BASE ERROR" when I click that link.....same as Tom H's link (above).
0
FollowupID: 873018

Follow Up By: Member - Roachie - Sunday, Aug 14, 2016 at 16:59

Sunday, Aug 14, 2016 at 16:59
SNAP.... John beat me to it!!!. hahaha
0
FollowupID: 873019

Follow Up By: TomH - Sunday, Aug 14, 2016 at 18:22

Sunday, Aug 14, 2016 at 18:22
Try this then
http://www.larpro.com.au/larpro/Home And go down to electrical connectors

Click the first link a couple of times it seems to come right if you do

You can buy those blocks for different size cables at Jaycar I have used them on car stereo instalations
Also using a larger than normal tube can be crimped into a C shape and then squashed in a vice. Did some Clips for a jumper cable last week and they wont pull out in a hurry Was using 3 G welding cable
1
FollowupID: 873021

Follow Up By: Nomadic Navara - Sunday, Aug 14, 2016 at 18:36

Sunday, Aug 14, 2016 at 18:36
Copy and paste this into a new tab:

http://www.larpro.com.au/larpro/product/1553

It worked OK in the preview but after I submitted the message it does not work
PeterD
Retired radio and electronics technician

Lifetime Member
My Profile  Send Message

1
FollowupID: 873022

Reply By: Zippo - Sunday, Aug 14, 2016 at 19:24

Sunday, Aug 14, 2016 at 19:24
I'm with AllanB regarding DECENT crimps (not those pissy Faston/QC types) vs soldering, and I CAN solder!
Soldering creates stress points where flexing loads will be concentrated, far more than crimping. In addition, it is NOT trivial to get the right amount of heat and even heat distribution when soldering bigger cables like those you are faced with.
Rather than pursuing unequal butt splices, a method I often use is to find the splice connector size that will allow BOTH cables to enter (EDIT: from opposite ends) and overlap them for the full length of the splice.
AnswerID: 603393

Reply By: nickb - Sunday, Aug 14, 2016 at 21:39

Sunday, Aug 14, 2016 at 21:39
I have used 50mm-16mm reducing lugs before, they are from Cabac (an electrical wholesaler should be able to help you out), not sure what other sizes they have.

http://www.cabac.com.au/products/lugs-and-links
AnswerID: 603405

Reply By: Member - John (Vic) - Monday, Aug 15, 2016 at 01:42

Monday, Aug 15, 2016 at 01:42
Your other option is to put a fuse such as an ANL or Midi fuse in between the two different gauges of wires and use a suitable crimp lug in and out of the fuse holder.

Aside from the fuse helping to protect the BCDC charger and system as a whole it fixes the issue of trying to connect the two wire gauges.
This is just what I did when mounting my BCDC charger, I put an ANL fuse holder on the positive lead into the BCDC and one on the output to the secondary batteries, bracketing the charger.



VKS737 - Mobile 6352 (Selcall 6352)

Lifetime Member
My Profile  My Position  Send Message
Classifieds: Water Tank 55 Litre

AnswerID: 603409

Follow Up By: Nomadic Navara - Monday, Aug 15, 2016 at 09:35

Monday, Aug 15, 2016 at 09:35
Unless you have a battery (or other high current voltage source) on each end of the wire you should have only one fuse in the line. Every fuse in line causes a voltage drop. The extra fuses also are an extra potential source of problems.

I think Zippo's method is the best way to go.
PeterD
Retired radio and electronics technician

Lifetime Member
My Profile  Send Message

0
FollowupID: 873041

Follow Up By: Member - John (Vic) - Monday, Aug 15, 2016 at 13:42

Monday, Aug 15, 2016 at 13:42
Umm you do have a battery on each end of the wire.
Input current comes from the start battery whilst being charged by the alternator, up to 14.2v, in my case the ANL fuse has almost zero impact on voltage drop.
On the output side the BCDC raises the voltage to suit my AGM's 14.5v so certainly no voltage drop there either.
It's also the way Redarc recommend you wire the unit to protect the system as a whole.

Redarc BCDC wiring diagram

VKS737 - Mobile 6352 (Selcall 6352)

Lifetime Member
My Profile  My Position  Send Message
Classifieds: Water Tank 55 Litre

1
FollowupID: 873043

Sponsored Links

Popular Products (13)