I am replacing my OEM battery cables and terminal clamps. I've got the negatives done but need some help on the passenger side positive. I'm using "military" type terminal clamps to allow me to wire a winch up to the battery. I have had a new crossover positive made with 3/8" lugs on each end and will crimp new 3/8" lugs on the existing starter lead on the passenger side batt and alternator charge wires as well as the driver positive that runs to the relay box. The problem I have is getting the starter lead up and over the top of the battery to attach the 3/8 lug to the terminal clamp. I think the starter cable is at least 2/0 and it isn't going to bend. It worked great for the Ford terminal clamp that dives over the back of the battery at a 90 degree angle but isn't conducive to wiring my military type terminal clamp.

My plan is to fabricate a copper bar with 3/8 holes in both ends about 2 inches long so it will extend over the edge of the battery case. Attach one end to the terminal clamp and the other to the starter cable that can now remain in it's vertical orientation. I'll wrap the exposed copper bar in adhesive lined heavy wall heat shrink save for the attachment points. My question is how thick should the copper bar be if it is 3/4-7/8 wide and 2 inches long. Should I "tin" the exposed copper beyond each end of the heat shrink. I'm running a Diehard Platinum with 930 CCA. I'm open to better suggestions. I would like something rigid versus just a cable extension and I don't want thickness I don't need on the copper bar as it would take up available length of the stud on the clamp. I could make the bar wider if I need with the extra width sticking up a bit above the battery but I don't know what the calculations would be to ensure I don't melt something. Any help is very much appreciated. I've been monkeying with how to go about this for months and just want to get it set up.
Eric

 

I am not sure what a solution to your problem would be, but there are two things in your post I do not like.

1.This doesn't sound right. If you are using 2/0 cable, it should be welding lead cable, and that has plenty of flexibility to it. Using a stiff cable in a automotive application is not good with all the movement and vibration.

2.I again see warning flags popping up in my mind. I do not recommend "hanging" a lot of rigid bar off the battery terminal, and then a very stiff cable on the end of that. Vibration and flexing can eventually cause it to fail and possibly crack the case of the battery. You also do not want a bunch of un-insulated metal under the hood at battery potiental. If you are in a accident, the hood can come down, or the battery pop up and short this stuff out and cause a fire.

 

I haven't replaced the starter to battery cable, it's OEM from Ford, 2/0 and stiff. Ford did a good job supporting it and I'm not planning on changing any of their support points on the cable. As far as welding cable, I looked into that and actually bought the cable to make the new negatives and positive crossover cable only to find out that welding cable insulation is not oil resistant and not recommended for underhood/automotive installation. It's great for jumper or inverter cable from what I understand. I was able to return it and spent the extra for STX automotive cable from custombatterycables.com. Cost a bit, but very happy with their product. What you mentioned about having stuff hanging out there ready to short in the event of hood collapse or something of that sort was something I was worrying about. I thought the heat shrink around everything not necessary for making a connection would protect against that as much as I could. As it is right now there is a fair amount of terminal clamp hanging down the side of the battery. It is an odd looking clamp, crimped to the starter cable on one end and the crossover cable on the other. The starter side of the clamp actually lays flush on the top of the battery and then folds over the back of the battery and down to the crimp. I appreciate letting me know of the concerns but like you said I can't think of another way to facilitate wiring my winch. I imagine I will double thickness the heat shrink tubing around the copper bar, I'm not sure what it's insulating properties are but I bought it from the guy that made my cables as he uses it to seal his crimps on the cables he uses. The only additional exposure would be where I make the connection of the copper bar to the 3/8 ring terminal I'll crimp on the 2/0 starter cable. I've gotten some guidance in the superduty forum as to the size of the bar I will need so I'll probably give it a try and see how it looks/functions unless I have some type of epiphany as to a better way of doing it. I honestly have no idea how guys wire their winches in a diesel superduty with the OEM terminal clamps and I wasn't able to get any good answers either. I came up with this from a Jeep forum. They didn't use a copper bar like I'm planning but the military type clamps were their choice as far as ease of wiring accessories. I'm hoping this all works. Thanks for the response.
Eric

 

Check Boating Stores or NAPA's catalog, they'll have what you need ready made.

 

There is a difference between welding cables and batterie cables becarefull useing welding cables on positive side as alot are not oil resistent and the caseing will swell up and come off . Choose Wisely

 

Check out my album at Ford Truck Enthusiasts Forums - artfd's Album: Buss bar
Brass is much cheaper than copper. I have not needed to attach such a thick cable as you propose, but it would be easy to do with my setup. Use brass nuts & bolts to avoid galvanic corrosion. I bought a dirt cheap seat of taps & dies from Harbor Freight & tapped threads in the holes of my buss bar, it was easy doing that with brass. The wing nut has corrosion around it since it's iron & not brass.
I showed my creation to an electrical engineer, he thought I could draw at least 200 amps through all this metal without overheating or excessive resistive loss. (This is more than the battery can tolerate). Brass has more resistance than copper, but it doesn't matter in a structure of this size. Copper would be nice, but very expensive and unnecessary.
I have been running this system for 5 years & 50,000+ miles with no problem. I think if you hang a 2/0 cable off this buss, you should put a supportive bracket on the cable or lash it to the battery to prevent vibration.

 

Thanks for the reply. I hadn't thought about using brass. I ended up buying a piece of 3/4x3/8 copper bar from an online metal store. I got about a foot of it for $12. With shipping it came in at about $20. It has worked out really nice. I have to admit I haven't gotten the winch wiring pulled for it yet. Been very hot here in Louisville and too much other stuff going on. The installation went pretty smoothly and it all looks really nice. The only part that casued any problem was running the crossover cable where I had to disconnect the radiator upper supports to allow enough wiggle room to feed it across the truck. I heat shrinked the bus bar between the contact points for protection and everything is very solid. When I get around to it I will have plenty of room to attach the winch wiring using some ring terminals.
Eric.

 

I'm lucky I live fairly close to a McMaster Carr supply warehouse. They have some astounding deals on materials of all kinds, no minimum order. I can drive to their Will Call office sometimes as soon as an hour after placing an order online. That's where I got my brass bar, a fraction of the cost of most other places I looked. Brass bars slightly thicker and slightly thinner are much more expensive, don't know why the 1/4" material was the cheapest. Always check them first if you are going to have something shipped to you.