Author Topic: Using 3/8 inch copper tube for battery connections  (Read 7327 times)

0 Members and 1 Guest are viewing this topic.

madlabs

  • Hero Member
  • *****
  • Posts: 686
  • Country: us
Using 3/8 inch copper tube for battery connections
« on: April 24, 2009, 02:21:54 PM »
Hi again All,


Sorry to post so much, I don't want to bug y'all, but I have so many questions....


Any problem with using 3/8" copper tubing to connect up my battery bank? I am on a serious budget and have some of the tube kicking around. It's already been would into a tight spiral for a beer making wort chiller that I no longer use. So it's not like it's nice new tube or anything. I would solder lugs on the end.


Thanks!

« Last Edit: April 24, 2009, 02:21:54 PM by (unknown) »

TomW

  • Super Hero Member Plus
  • *******
  • Posts: 5130
  • Country: us
It works but...
« Reply #1 on: April 24, 2009, 08:56:12 AM »
mad;


In my first battery bank I used copper tube as interconnects. Trojan 105 batteries have a stud terminal so I used half inch tube, hammered flat with a hole for the stud.


It worked but I would not do it that way again. A bit dangerous if you have those big areas of conductor exposed and a wrench or other metal object gets across them.


Again, it works but I would recommend you avoid it for several reasons.


Good luck with it.


Tom

« Last Edit: April 24, 2009, 08:56:12 AM by TomW »

AbyssUnderground

  • Sr. Member
  • ****
  • Posts: 461
Re: It works but...
« Reply #2 on: April 24, 2009, 09:13:00 AM »
You could always cover it with rubber/plastic of some sort if its a large area, couldn't you? If its convenient of course.
« Last Edit: April 24, 2009, 09:13:00 AM by AbyssUnderground »

deloiter

  • Newbie
  • *
  • Posts: 43
Re: It works but...
« Reply #3 on: April 24, 2009, 10:34:45 AM »
I did the same thing with my 105s and for insulation I used heat shrink that I had purchased surplus in a large quantity.  It was cost effective at the price I paid but I don't about cost in small quantities.
« Last Edit: April 24, 2009, 10:34:45 AM by deloiter »

ClintonC

  • Newbie
  • *
  • Posts: 1
Re: Using 3/8 inch copper tube for battery connect
« Reply #4 on: April 24, 2009, 12:09:00 PM »
I used a couple of old garden hoses as the insulator. I cut the pieces longer than the pipe and split the ends to make a flap to cover the terminals.
« Last Edit: April 24, 2009, 12:09:00 PM by ClintonC »

scottsAI

  • Hero Member
  • *****
  • Posts: 884
Re: 3/8 inch copper tube for battery connections
« Reply #5 on: April 24, 2009, 01:55:14 PM »
madlabs,


Consider using Adhesive Lined Heat Shrink, costs more, keeps the acid from crawling up the tubing.

Now if you can keep if off the terminals then maybe you don't need it.


Drill hold in pipe, not use spade connector. Like Tom said.


**Make sure you coat the terminal end with solder**

want similar metals in contact with each other. No copper and lead mechanical interface.

Soldering it's chemically bonded to the copper. No dissimilar metal interface.


Have fun,

Scott.

« Last Edit: April 24, 2009, 01:55:14 PM by scottsAI »

TomW

  • Super Hero Member Plus
  • *******
  • Posts: 5130
  • Country: us
Re: 3/8 inch copper tube for battery connections
« Reply #6 on: April 24, 2009, 04:34:14 PM »
Scott;


I picked up a bunch of tubes of ox-gard terminal grease and now I use it on all connections inside or out, similar or dissimilar metals it seems to work very well keeping oxidation in check.

Bought a whole box of them from an industrial surplus place for dirt cheap. quarter a tube or something. Doesn't take long for copper on lead to go nasty and then you have all kinds of resistance in your connections eating power and causing thermal issues. As someone else pointed out, expansion and contraction of solid interconnects can actually damage the cells from the movement.


Tom

« Last Edit: April 24, 2009, 04:34:14 PM by TomW »

scottsAI

  • Hero Member
  • *****
  • Posts: 884
Re: 3/8 inch copper tube for battery connections
« Reply #7 on: April 24, 2009, 05:42:23 PM »
TomW,


That's a very good idea!

Following NEC code requires the battery terminals to be of the same metal. Not hard to coat with solder and use the ox-guard. Thanks.


Scott.

« Last Edit: April 24, 2009, 05:42:23 PM by scottsAI »

madlabs

  • Hero Member
  • *****
  • Posts: 686
  • Country: us
Re: Using 3/8 inch copper tube for battery
« Reply #8 on: April 25, 2009, 08:52:20 AM »
For some reason my last two posts didn't show up. Weird. Maybe this one will.


Would 1/4" tube be large enough? I have some of that laying around and have the heat shrink to cover it. Is there anything I can use as adhesive to prevent acid creep? Would shaping the tubes into arcs help in terms of expansion and contraction? At least then the expansion pressure would be downwards.


Such amazing practical info! Thanks for all the lengthy replies!


Jonathan

« Last Edit: April 25, 2009, 08:52:20 AM by madlabs »

ghurd

  • Super Hero Member Plus
  • *******
  • Posts: 8059
Re: Using 3/8 inch copper tube for battery
« Reply #9 on: April 25, 2009, 08:59:13 AM »
That 1/4" stuff won't leave much copper beside the holes.

G-
« Last Edit: April 25, 2009, 08:59:13 AM by ghurd »
www.ghurd.info<<<-----Information on my Controller