# battery cable connectors solder on or press on ?



## kennybobby (Aug 10, 2012)

i wear a belt and suspenders in critical applications--do both and sleep easy.


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## Tesseract (Sep 27, 2008)

Not so fast, kennybobby... Crimping is generally the best method for attaching lugs to cable, especially in high vibration environments. This is mainly because a good crimp is easier to achieve than a good solder joint, but also because it is very difficult to properly solder large diameter cable without seriously damaging its insulation and even if you do, you've turned a flexible, multi-strand cable into an inflexible, single-strand wire. Damaged insulation and stiff wire aren't a good combo in an EV bouncing down the road...

A hydraulic crimper is the absolute best, but the manual or ratcheting types with long (like 1M long) handles that use separate dies for each size of cable also works well. Least preferred, but still capable of making acceptable crimps, is a hammer crimper. For best results with the hammer crimper you need to hit its striking anvil squarely with a 3lb-5lb mallet.


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## mizlplix (May 1, 2011)

I fill my fittings with paste, insert cable, crimp and solder with the lowest temp solder I have and do a clean up before shrink sleeve. *With the cabling secured properly*, there has been no cracking or loosening issues so-far in 3 EV's. A manual crimp tool is best. It can do repeatable same pressure crimps that a hammer type can not.

If crimped properly....the wire should not move inside the crimp.

So, any flexing will be outside the crimp.

OR where the solder stops. (same deal)

Copper is too soft and work hardens too easily to allow it to continually flex. A failure will result. 

Overheating damage is a problem, that can be minimized with low temp solder and moderate heat. 

I always use GOOD shrink sleeving with the goo inside to both keep moisture out plus give more support to the soft copper wire.

Just my $.02

Miz


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## Sunking (Aug 10, 2009)

You can do both, but if you use UL Listed Compression with a system like those made by Burndy or T&B using 14 and 15 ton Hydraulic tooling, solder cannot match the quality or resistance. If you were to solder after the compression would only weaken the connection from thermal expansion. 

I know the NEC does not apply to the Auto Industry, but solder alone is not permitted because it has very POOR Mechanical strength. You have to use both a mechanical method like irreversible compression connectors for mechanical strength, and then solder if you wish. 

As mentioned if you solder large gauge conductors, the insulation is more times then not damaged from the heat. To do it correctly would require an Induction Heating method followed by a fast cooling. I do not think that is within reach of a DIY application. If I were going to do it, I would take th ecables to a Professional cable shop that has both the tooling for compression and induction heating.


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## dragonsgate (May 19, 2012)

My friend and owner of a NAPA store has a hydraulic hose crimping machine. It makes a beautiful looking application and those wires are in there to stay. He said he would do them for me but after the first half dozen he showed me how to work the machine and then let me do the rest of them.


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## evmetro (Apr 9, 2012)

I have not put my build to the test yet, but I have been cutting 3/4" copper pipe and flattening it out with the 0/2 welding cable inside. I have been leaving about 1.5 inches of bare wire so that it can sread out from round to the new flat shape. Once I squash the cable flat, I put the bare area in the vice so that the solder does not make the bare area stiff. The gbs batteries have posts that are square with 5 screws to retain the cable, so I drill the five holes after I solder. If I do not solder, the drill bit rips pieces of wire out. If anybody has any advice or even just some criticisms, please post. This is my first build, so I love to get slapped around a little if I am not doing it right...


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## dragonsgate (May 19, 2012)

The raw copper is likely to oxidize and corrode if it is not coated with a tinning or some kind of suitable sealer.


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## evmetro (Apr 9, 2012)

What is a good sealer? Is the tinning something that can be done diy?


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## EVfun (Mar 14, 2010)

In a good crimp oxygen is excluded from the connection. I have cut apart crimped lugs to find the copper strands have been turned from round into hex shape. You should easily be able to take a good crimp connection and bolt the terminal to a rafter and climb the cable.

Crimped lugs have worked well for years. Short of documented failures of properly crimped connections, or evidence that it is hard to properly crimp connections, I don't see any reason to change. I've had one bad connection in service, but it was a slow increase in resistance. I replaced the cable 2 years later when I replaced the pack. I have had a couple fail on crimping with the lug cracking. Those where never put into service. I've crimped more cables that I can count in a number of EVs.


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## Sunking (Aug 10, 2009)

evmetro said:


> What is a good sealer? Is the tinning something that can be done diy?


I can answer this. The absolute best is NO-OX-ID A Special. This is what every Telecom, Electric Utility, Rail Road Electricians uses to prep their wire skinners, connectors, nuts, terminals washers, and bolts.

I work in the Telecom and utility sector and this stuff is required on every connection and termination. To use it, especially on larger conductors we use a hot plate to set the can on to melt the grease. When the wire is Skinned, it is dipped into the grease then shaken off to remove the excess. The compression terminal is also dipped and shaken to remove excess. 

In addition we require a light coat to be applied to the mating surfaces before termination to the terminal. 

The stuff last forever even in salt air outdoor pad mount applications. There are terminations out the with 30+ years of service. No professional telecom or rail road battery installer would be caught dead with out it. They also make an Iron Workers and Bridge Builders grease used on all bridges used worldwide to prevent rust and corrosion in the rivets and bolt connections.


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