Thread: Replacing battery terminals/leads - what best to replace with?

I used 4B&S cable, as that's what the second hand DBS came with as a complete kit.
For lug ends I got the correct sized lugs for each cable, cut cables to length, and soldered the lugs to the cable(I think solder is much stronger than crimping over the long term).

To solder the lugs I heated them up with a cheap gas torch($5).
Held the lug in one hand with long nose pliers while heating the lug itself. The lug gets hot and stays hot, so it gives you a fair while to 'fill it' with solder and remain hot.
Once the solder fills up to the cutout on the lug, insert the cable, and the moment you insert the (colder)cable, the heat transfer between cold cable and hot lug/solder immediately sets the solder the moment you insert the cable and the cable has stuck.
I weigh 105Kg and it can easily take my weight. I stuffed the first two up and forgot to insert the heat shrink before I soldered the lugs, and the only way to get the lugs off is lots of heat and force at the same time.
So I'm 100% confident that the connection is strong. I used to coats of heat shrink on the power connections and just the one for the earth cable connections.
I reckon it's the cheapest way to get a good strong cable/lug connection.

I don't trust those bolt down type clamps, my D1 had one on the earth when I got it, and part of the reason I decided to add the DBS too, as I was going to have to red the crappy bolt on crimp and the positive leads crimped connector ... so I may as well do it all as a single job lot.

I found some nice looking multi connection battery terminals that I though would be handy:

Projecta Three Way battery Terminal on ebay.

I've bought a few items from that autoelecau now and their service is very good.

Both my batteries(in engine bay) use these three way terminals.
I hate having to trace some electrical issue and needing to remove all the accessory wires at the same time. These allow you to remove(or add) as you please.
The only issue to watch for with that type of terminal is on the drivers side post. The size of the connector comes 'perilously' close to the fuse box. It does eventually fit, but you need to watch for it if you want to use them.
That ebayer has a great range in their store, and also has a two way terminal as well, but having these three way types now, I'd never use anything else.

Actually...soldering is not as good as a proper crimp

When you get high current draw and the joint heats up the solder actually flows out. This is why high current terminations are never soldered, always mechanically crimped

Was one of the very first things taught to me as an apprentice

In saying that, a soldered joint should not get hot enough with general use ( excluding large amounts of winching etc )

As always, everyone is fully entitled to their opinion on what's best for them .. but! ...

Originally Posted by Morry948

....

When you get high current draw and the joint heats up the solder actually flows out. This is why high current terminations are never soldered, always mechanically crimped

.....

I measured the temp(IR temp gun) at which the solder hardened which was a touch over 300°C once the 4B&S wire was fully adhered to the lug.

I'm thinking that if you're current usage is heating up the wire to over 300°C with such heavy gauge wiring .. the loosening of the solder would be a good thing!
Can't see that the protective jacket on the wire would last more than a few seconds at that temp before it self-combusts and burns down the vehicle.
So if the solder liquefies and breaks the connection .. think of it as a good breaker circuit to eliminate runaway heat generation!

At first I couldn't work out how to heat the wire to get solder onto it without stripping the jacket too far back as the heat of the solder iron would just melt the jacket.

Under the bonnet with the Aux on the passengers side I use all 4B&S cable, max continuous length from the aux to the Redarc isolator was about 2m(less, but close enough).
For the power to the rear D1 I had a long length of 8B&S to use, so went with that. About 5m in length.
For the last two connections I made for the long 8B&S cable to the rear of the D1, I pre soldered the cable using the heated up lugs method.
Heat the lugs and fill with solder insert the cable. Cable would take solder. Then heat the lug again to remove the cable and the cable was then nicely soldered, and redo the connection but now with a nice even coat of solder on the cable.

I have always been told that a good crimp is better that solder, The secret is getting a GOOD crimp done.
Those flat crimpers/wire strippers that come in the little kits you can buy are totally useless and the best place for those is in the bin, Buy yourself a Good set of crimping plyers or even one of those hydraulically operated jobbies so that you can easily create a good sound crimp.

Cant beat good old utilux style ratchet crimpers for upto 6mm :-)

Most people use the wrong size lug for the wire which creates even more issues ( which is why they are colour coded )

For battery terminals, I would suggest lead coated brass. A proper crimp is meant to be better than solder. With the right amount of force, the copper is meant to cold weld to the terminal. All of my added fittings are soldered. I use a large iron to get both the terminal and cable hot enough to solder. Plunging a cold cable into a hot terminal full of solder can result in a cold joint. One problem that can result from soldering, is that solder flows up the cable making it rigid. The cable is then prone to breaking.

Aaron.

Originally Posted by Morry948

I prefer these type, but they are not perfect. Gives better high current performance for started motors and winches with 10mm+ cable

Lugs/clamps/post/connectors are only as good as the surface area they make contact with. More surface area means less resistance and heat where they join ( used to work on 50v battery systems capable of a few hundred amps )

You can also use longer bolts and turn them upside down ( ie feed them from underneath ) with a nut on top over the clamp plate, then just use the bolt as a terminal post

And use wool fat ( Chemist --> baby aisle ) on the terminals to stop corrosion. Its much better than petroleum jelly.

I had those on my D1 and found them very good.

Originally Posted by Aaron IIA

One problem that can result from soldering, is that solder flows up the cable making it rigid. The cable is then prone to breaking.

Aaron.

This because people use wwwaaayyyy to much solder. Less is best