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diy solar

Crimp battery and inverter cables without special tools $0

One problem with any hammer type crimp is the crimp is not airtight. Over time, copper oxide is formed. Another problem is surface contact area inside the crimp. A properly crimped terminal will have a cold weld where the strands are bound so tightly the individual strands become one. This is an increase in surface area contact not only between strands but also to the terminal. Higher surface area contact reduces resistance, which results in less voltage drop, less heating of the terminal and higher current transmission thru the terminal.

As for solder, it works until it doesn't. If the terminal becomes hot, the solder may fail resulting in the solder running out and/or the wire could come out of the terminal leading to arc flash/fire. The resistance is higher than a tightly crimped terminal, voltage drop tests across the connection can be quite revealing under higher load conditions.

I've worked in the automotive industry for over 35 years and have seen just about any type of failure you can think of. For the price of this crimper, you can't go wrong. I've owned them all, from the hammer type to the large pliers type, even soldered terminals back in the day. The Temco is by far the best crimper I ever owned.
Thanks for explaining this. In a hot and dry climate such as mine, I don’t expect copper oxide to form quickly if ever. The poor solder job was my issue here.

I now understand why a $175 hydraulic crimp tool is superior, but if it was mission critical, why does Will recommend hammer style crimpers? In a marine environment or for NASA, sure, but for dry climates, is it really that necessary?
 
What’s dangerous about this kind of crimp? I mean there are hammer style crimpers, what’s wrong with this redneck version?
That you have to ask illustrates the issue that I'm trying to point out.

What size are those screws? What hardness are they? Can you repeat it? How many times can you repeat it? What are your test standards? What standards are the instruments you're using to measure calibrated to? How long since thier last calibration? On and on I could go....

Future readers.... you've spent thousands of dollars, maybe tens of thousands of dollars and you're going to trust the most important connection in your entire system to some random screws and a sledge hammer head you found laying around?

So much dangerous hacking on the forum lately. One recent thread from a newby went on for days before someone finally realized the OP didn't know how to use a DVM. Another recent thread has a newby using nothing but green wire. Green for the AC hots, green for the AC neutrals, green for DC negative and green for the DC positive. Why?

I prefer hex crimpers. We have the bench mount "commercial" version of this $33.75 hex crimper.
 
Thanks for explaining this. In a hot and dry climate such as mine, I don’t expect copper oxide to form quickly if ever. The poor solder job was my issue here.

I now understand why a $175 hydraulic crimp tool is superior, but if it was mission critical, why does Will recommend hammer style crimpers? In a marine environment or for NASA, sure, but for dry climates, is it really that necessary?
I've provided the best path forward. You can choose to adopt a standard that is widely accepted as best practice or superior to other practices.

I've run a successful business for 35 years. I belonged to an industry forum for about 20 of those years comprised of 55,000 professionals, engineers, major distributors, educators, manufacturers and researchers where information was freely shared including theory, standards and operating procedures. It was referred to as the University. One thing I have learned over that time is that if best practices are followed and SOP (standard operating procedure) is put in place for a company and it's employees, the quality and success rate of the procedure/product is superior in all aspects including safety, longevity, customer satisfaction, and long term economic value.

The choice is yours. While you can justify it to yourself to not accept a standard, SOP or best practice; the end result may not be safe, have longevity, satisfaction and long term economic value.
 
Crimper are like wire strippers... yeah, you can DIY, but the tools that are designed for the job are, in fact, better/cleaner/time saving. In a pinch, I'd use your method to crimp a wire ( or a razor blade to strip it). Long term, though, a hammer or hex crimper is relatively cheap compared to the cost of the project and the safety of the installation.
 
You can use some shrink tube to make it air tight.
Standard heatshrink is great for a lot of things - reducing fatigue, identification, insulation etc. But if you want it to be waterproof, the you need the glue lined heatshrink. This stuff is tough and provides a lot of protection above standard heatshrink.

An alternative is 'liquid insulation tape' that can be painted on.

 
You can use some shrink tube to make it air tight.
This is a great idea! I was planning on doing so anyways, but I never thought about (marine grade/glue lined) heat shrink helping keep moisture and air out.

Update to my original post. While my redneck crimp job got the job done, I won't be doing it again. I borrowed a type of hydraulic crimp tool, the thing was massive, but it wasn't the right kind for making good crimps. So I have a hammer crimper coming in the mail. Which to the pros on this thread, is far inferior to a hex-style crimper, and I agree, but it's far superior to any of the soldering or crimping I've done so far. If I were wiring up for my home I lived in, I would certainly just buy the $37-70 tool to do it the best way.

But if you want it to be waterproof, the you need the glue lined heatshrink. This stuff is tough and provides a lot of protection above standard heatshrink.
Yes. I am finding that it depends upon the application. If it's a situation where I think I might want to remove the heat shrink, I use the regular non-gluey stuff. That glue leaves a sticky mess behind (not to mention being much more expensive).
 
Standard heatshrink is great for a lot of things - reducing fatigue, identification, insulation etc. But if you want it to be waterproof, the you need the glue lined heatshrink. This stuff is tough and provides a lot of protection above standard heatshrink.

An alternative is 'liquid insulation tape' that can be painted on.


amalgam tape is what we used for satellite work.
 
I have a ratchet crimping tool which works very good. Im struggling with the thought that a soldered joint isnt as good as a crimp. More contact area with solder.
 
I have a ratchet crimping tool which works very good. Im struggling with the thought that a soldered joint isnt as good as a crimp. More contact area with solder.
A "good" crimp is significantly better than soldering as described above, but a gotcha for soldering is the solder wicks up the filaments making it very stiff. The point the solder stops acts as a sharp stress concentrator that can easily become the fracture point.

amalgam tape is what we used for satellite work.
Also good!
I've used my share on antenna feed lines too.
It's a lovely sight when you pull apart an antenna feed that's been out in the weather for 20 years and the connectors are still dry and bright.
 
A "good" crimp is significantly better than soldering as described above, but a gotcha for soldering is the solder wicks up the filaments making it very stiff. The point the solder stops acts as a sharp stress concentrator that can easily become the fracture point.


Also good!
I've used my share on antenna feed lines too.
It's a lovely sight when you pull apart an antenna feed that's been out in the weather for 20 years and the connectors are still dry and bright.

PV, has this actually been proven? Don’t get me wrong, I’m not calling you guys out, just that to me there is complete contact area with a soldered joint. I struggle to see that a crimp would have the same contact area as say the wire itself.
 
Ok, so I did some research. The consensus is crimp is better if the right crimp tool is used. Whith that said, I couldn’t find anywhere a statement made that said a crimp had the same or lower resistance to solder!

Cheers guys.
 
I have to admit I was also skeptical when I was first told crimping was better, but when you realise all automotive, aviation and military connections require crimp connections in most applications, it does look convincing.
The consensus is crimp is better if the right crimp tool is used.
That of course is a problem - I've lost count of the different crimping tools I have. From very fine ribbon cable though MC4's up to 70mm ^2
 
I have to admit I was also skeptical when I was first told crimping was better, but when you realise all automotive, aviation and military connections require crimp connections in most applications, it does look convincing.

That of course is a problem - I've lost count of the different crimping tools I have. From very fine ribbon cable though MC4's up to 70mm ^2

PV, has anyone done a resistance test between the two?

When it comes down to the likes of the automotive field, from what I understand, its more about durability.
 
This^^^^^ Especially for large cables.
Which was my problem in this case! I have only a little soldering experience, usually with 14-22AWG, not pretty, but it worked and no oxidation. With 1AWG, I had to use a torch and I may have had the wrong flux and I think I over heated the cable and well what happened is we were getting inverter shutdowns and bad voltage sags in the battery. Not sure if the sags were all due to a bad cable, but when I removed the 1AWG cables that had been solders, I cut off the oxidized part. And kept cutting and kept cutting. I cut off about 3 inches before I gave up and deemed that there was no good cable left in it. Never again!
 
Which was my problem in this case! I have only a little soldering experience, usually with 14-22AWG, not pretty, but it worked and no oxidation. With 1AWG, I had to use a torch and I may have had the wrong flux and I think I over heated the cable and well what happened is we were getting inverter shutdowns and bad voltage sags in the battery. Not sure if the sags were all due to a bad cable, but when I removed the 1AWG cables that had been solders, I cut off the oxidized part. And kept cutting and kept cutting. I cut off about 3 inches before I gave up and deemed that there was no good cable left in it. Never again!

So you actually saw black residue on the copper cable, maybe from acid flux?
 
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