Crimp battery and inverter cables without special tools $0

[Tomthumb62]

UPDATE: DON'T DO THIS! While this redneck crimp was cheap and worked in a pinch (ha ha), y'all have convinced me this is a bad idea. For a very short-term fix under low loads, probably no problem. But if you intend to push the limit of amps through such a cable and especially if you plan to use this cable/lug over a long term, you risk fire or electrical gremlins. Without all the air gaps inside the lug and cable, oxidation can creep in and compromise the ability for amps to get from point A to B. Don't do what I did. This post was originally under a different forum, but a mod wisely moved it to the Up in Smoke one.

The consensus of this thread to do a crimp the best way is to use a $40-80 hex-style hydraulic crimp tool. They come with different dies, use the correct size for the size of cabling you're doing. HF has one for about $70 and this $50 one was recommended on this thread. Or go pro for the $174 one.

Now back to my original low-budget route, I bet with a good heavy bench vice and this $16 die set, you could do it. But it might be more challenging to get it all to fit properly in a bench vice, something could easily slip - some tape or a helper set of hands would do the trick. In fact, I just ordered these dies and will be returning the hammer crimper. I'll update my post after I try it out. Business opportunity here - someone could make a hammer crimper but uses these kind of dies instead, cost could be what? $20-25? For someone like me who is only going to occasionally make such crimps, it makes more sense than having a more expensive tool.

Original post:
I didn’t need to buy another $40 tool for two crimps, so I made my own hammer crimper. Cost $0.

I needed to crimp new copper lugs to 1AWG cable, so I did this:


Slid heat shrink on first. Placed lug onto cable. Taped two small screws onto top and bottom of lug using electrical tape. Placed this jig onto a flat rock and used a sledgehammer head I had sitting around but a heavy rock would do or a hammer. One or two solid taps on each side put a nice crimp on. Tap right onto the top screw. Make sure the two screws are aligned with each other so you get an even crimp.




Did a good crimp

 

[Don B. Cilly]

I do the same, actually. First I solder. I'm quite good at it, and I believe I do it properly.
Then I give the lug (quite) a few bangs with a cold chisel. I use a piece of wood as anvil. Dent it in two places, at slight angles.
-

 

[Tomthumb62]

I do the same, actually. First I solder. I'm quite good at it, and I believe I do it properly.
Then I give the lug (quite) a few bangs with a cold chisel. I use a piece of wood as anvil. Dent it in two places, at slight angles.
-

Yeah my solder job was horrendous. I don’t think I’ll ever do that again for larger gauge cable.

 

[Risky Rob]

Yeah my solder job was horrendous. I don’t think I’ll ever do that again for larger gauge cable.

I used lots of flux and a propane torch to heat the lug. It seemed fine.

 

[Tomthumb62]

I used lots of flux and a propane torch to heat the lug. It seemed fine.

That’s exactly what I did. TONS of black and green oxidation. Maybe it was cheap cable or something.

Anyways I heard Will say to never solder these joints, always crimp. I’m sure it can be done properly but is probably difficult to do for the average person.

Edit to say that I heard Will criticize a battery maker for using solder for the large main terminal connections. He prefers crimps.

 

[PVorBust]

I do the same, actually. First I solder. I'm quite good at it, and I believe I do it properly.
Then I give the lug (quite) a few bangs with a cold chisel. I use a piece of wood as anvil. Dent it in two places, at slight angles.
-

A good crimp has better mechanical strength and lower resistance than a solder joint, but hammering a solder joint will fracture the solder and degrade it's performance.
If you must do both, hammer first, then solder.

 

[Risky Rob]

That’s exactly what I did. TONS of black and green oxidation. Maybe it was cheap cable or something.

Anyways I heard Will say to never solder these joints, always crimp. I’m sure it can be done properly but is probably difficult to do for the average person.

Edit to say that I heard Will criticize a battery maker for using solder for the large main terminal connections. He prefers crimps.

There are differing opinions. Some lead free solder does a poor job. I have a 24V system with 2 gauge wire, so maybe that makes it easier. I use a round punch to start, rather than a direct hammer, and the vise to crimp. After that I heat the lug, and the flux seems to draw solder into the lug.

 

[PVorBust]

That’s exactly what I did. TONS of black and green oxidation. Maybe it was cheap cable or something.

Sounds like you used an acid flux. (not from our grandfathers toolshed was it?)

Flux is great, but you need to choose carefully.

A modern Rosin flux will give excellent results.
I suggest RMA223 intended for surface mount components



for more info on fluxes:

SMT Types Of Solder Fluxes And Its Requirements

The basic mechanism of soldering is controlled by the solubility of one metal into the other. For the formation of a inter-metallic bond, the metallic surfaces must be free of any contaminants

www.tutorialsweb.com

 

[Zwy]

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.

 

[Tomthumb62]

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.

Good info, thanks. My efficiency after repairing these cables was a night and day difference. I’ll retest every year to see if that changes. If I ever solder again, I’ll do it right and crimp first and solder second and use the correct flux.

 

[Tomthumb62]

Sounds like you used an acid flux. (not from our grandfathers toolshed was it?)

Flux is great, but you need to choose carefully.

A modern Rosin flux will give excellent results.
I suggest RMA223 intended for surface mount components

View attachment 114712

for more info on fluxes:

SMT Types Of Solder Fluxes And Its Requirements

The basic mechanism of soldering is controlled by the solubility of one metal into the other. For the formation of a inter-metallic bond, the metallic surfaces must be free of any contaminants

www.tutorialsweb.com

Thank you. I had no idea there are different fluxes. I can’t even recall which one I used. And it very well may have been from my 90 year old friend’s garage, which is where I did the soldering.

If I ever try again, I’ll use the right stuff.

 

[740GLE]

Also most flux is an acid, and if left on copper will cause green death. This is why everyone says crimping is the way to go.

 

[SolarRich]

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.

I use the same crimper. There are other brands that look the same and perhaps they are.
Works great!
Airtight connections are extremely important. It may take years but the copper in poorly crimped connections will corrode. Resistance will increase and now, years later, you are not looking at the connections any longer so you don't see the problem. That's when those poorly crimped connections get hot and the system will fail.

 

[rhino]

A lot of "accidents"/fires we've seen posted here are likely due to poor connections. Not using proper tool for this critical area seems unwise.

 

[Tomthumb62]

I use the same crimper. There are other brands that look the same and perhaps they are.
Works great!
Airtight connections are extremely important. It may take years but the copper in poorly crimped connections will corrode. Resistance will increase and now, years later, you are not looking at the connections any longer so you don't see the problem. That's when those poorly crimped connections get hot and the system will fail.

What about coating the bare strands with some oil or other anti corrosive treatment and just crimp no solder? Would dielectric grease be useful in this case?

 

[SolarRich]

What about coating the bare strands with some oil or other anti corrosive treatment and just crimp no solder? Would dielectric grease be useful in this case?

Wondered about using an oil as an oxygen barrier myself. On cars, yes I put oil on all connections that are exposed. Since I drive old beaters
I've seen huge 'ground lugs' used as wire to battery terminal connections(2/0) - and pass code inspection.

 

[time2roll]

I give in to about any excuse for a new tool.

 

[OzSolar]

I didn’t need to buy another $40 tool for two crimps, so I made my own hammer crimper. Cost $0.

I needed to crimp new copper lugs to 1AWG cable, so I did this:

To future readers of this post: Please don't follow this advice. You are messing with things could burn your house down and kill your family. Do it right or don't do it.

Tom I appreciate that you're trying to help but please understand that what you are suggesting is dangerous and should not be done.

 

[PVorBust]

For the price of this crimper, you can't go wrong.

I decided I didn't need the larger sizes and went for the smaller (cheaper) 10/12t version.
I payed considerably less than the current price, but they are still good value.

Edit: This is the tool I use - cost me less than $40

What about coating the bare strands with some oil or other anti corrosive treatment and just crimp no solder? Would dielectric grease be useful in this case?

You could do that after you have crimped - as @Zwy says, the crimp provides such high pressure the contact surfaces are welded together. Adding oil before the crimp will just degrade the performance.

 

[Tomthumb62]

To future readers of this post: Please don't follow this advice. You are messing with things could burn your house down and kill your family. Do it right or don't do it.

Tom I appreciate that you're trying to help but please understand that what you are suggesting is dangerous and should not be done.

What’s dangerous about this kind of crimp? I mean there are hammer style crimpers, what’s wrong with this redneck version?

The hardware store had the $40 crimp tool next to their bulk wire. They use it to also cut wire. I used their tool to make the first crimp. Then went home and did the second with my redneck method. I can’t see a difference, other than aesthetics. And the cable conducts 75-90 amps continuously, which is within the rating of 1AWG.

 

[Tomthumb62]

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?

 

[OzSolar]

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.

 

[Zwy]

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.

 

[rdhood]

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.

 

[AlanH]

You can use some shrink tube to make it air tight.