diy solar

diy solar

Crimp battery and inverter cables without special tools $0

Back in my car audio days, I'd only buy the open end copper ring terminals, crimp with a bench vice, solder the very end of the cable to the terminal, then heat shrink and loom all cables. Never had one fail. I don't trust the closed end types. You're better off going to a pawn shop and getting 4 or 1/0 AWG terminals made for audio systems than DIY crap on Amazon.
 
A Temco hammer-crimper is like $25. I consider that the very minimum. Two screws and a hammer isn't it. And you don't know what kind of crimp quality you're getting unless you cut it open, or put into service and measure resistance and heat. I get the shade-tree DIY angle for sure, I'm a master at it. Some things you just don't want to cut corners on, and cable lugs is one of them.

I cut a couple of my test crimps to verify a good cold-weld:



 
So you actually saw black residue on the copper cable, maybe from acid flux?
Yes. Last week I tried to clean the cable, using the vinegar+salt trick followed by a dunking in baking soda water. Lots of green powder came out of the cable. It looked much better and perhaps if I had removed all the insulation and cleaned all the strands better and then re-wrapped, I could've saved it, but not worth it and probably only a short-term fix anyways. Plus the new cables from Current Connected are NICE, extremely flexible for 1/0awg compared to the stiff 1awg I was using before. I only wish I had instead ordered a 2' red and 1' red instead of the 3' red, because then I wouldn't be in this crimping situation to need to cut the 3' and install lugs to install the inline ANL fuse. Wasn't thinking clearly, was reacting to stress instead of thinking it all through.

Like others have said, it might've been acid flux. Someone said it's not common anymore, but you might fight it in grandpa's garage. Which was where I found the flux, lol! Next time I'm over there, I will see if I can find it again and see if it's an acid flux or not.
 
A Temco hammer-crimper is like $25. I consider that the very minimum. Two screws and a hammer isn't it. And you don't know what kind of crimp quality you're getting unless you cut it open, or put into service and measure resistance and heat. I get the shade-tree DIY angle for sure, I'm a master at it. Some things you just don't want to cut corners on, and cable lugs is one of them.

I cut a couple of my test crimps to verify a good cold-weld:



Thanks for the photos and sacrificing at a lug (things aren't cheap lol). That does look nice. Budget is very tight right now, hence cutting corners. I took your advice and others and won't be doing the redneck hammer crimp again. I did borrow a hydraulic crimp tool, but it wasn't the hex style and simple made some pretty poor crimps, compared to yours. So I have one of the real hammer crimp tools coming - won't be as good as a hex crimp and probably won't get a cold weld like yours - but it will be head and tails beyond anything I've crimped so far. And sealed with marine grade adhesive heat shrink.

I'll edit my OP to warn people not to what I did.
 
There are advocates for 'die-less' crimping - because if the die doesn't fit exactly right it could be too tight causing ridges or deformation, or worse - too loose. The exact die, or a die matching your lugs, like you might get from Temco, is sure a great way to go, if not the most costly as well. If I was doing a lot of this type of work I would surely have the fancy Temco one with all the dies and their matching lugs. For a one-off, their hammer crimper does a nice job - hammer the crap out of it, it welds it. LOL And yes on the adhesive lined 3M shrink tubing - the only way to go for this stuff.

I also came to realize that many, if not most, tinned lugs are open, whereas the copper ones were closed. Frankly I like the closed end, and with a shrink wrap on there they are well sealed.

There are advocates for soldering, but there are just too many cons, not to mention the 'work hardening' that happens where the soldered strands meet the unsoldered strands in the wire, in a mobile application. AFAIK aircraft and military assembly requires everything to be crimped.

I did break down and buy a nicer wire terminal crimper - one of those ratcheting ones, and actual 3M terminals. There IS a difference in quality verses the china imports. The plastic insulator (pvc?) is better, and the terminal itself is of very slightly thicker material. They're just a lot nicer terminals. I've been getting by all these years with a cheapo pair of stamped metal crimpers and the cheapest crap terminals available. No more!
 
There are advocates for 'die-less' crimping - because if the die doesn't fit exactly right it could be too tight causing ridges or deformation, or worse - too loose. The exact die, or a die matching your lugs, like you might get from Temco, is sure a great way to go, if not the most costly as well. If I was doing a lot of this type of work I would surely have the fancy Temco one with all the dies and their matching lugs. For a one-off, their hammer crimper does a nice job - hammer the crap out of it, it welds it. LOL And yes on the adhesive lined 3M shrink tubing - the only way to go for this stuff.

I also came to realize that many, if not most, tinned lugs are open, whereas the copper ones were closed. Frankly I like the closed end, and with a shrink wrap on there they are well sealed.

There are advocates for soldering, but there are just too many cons, not to mention the 'work hardening' that happens where the soldered strands meet the unsoldered strands in the wire, in a mobile application. AFAIK aircraft and military assembly requires everything to be crimped.

I did break down and buy a nicer wire terminal crimper - one of those ratcheting ones, and actual 3M terminals. There IS a difference in quality verses the china imports. The plastic insulator (pvc?) is better, and the terminal itself is of very slightly thicker material. They're just a lot nicer terminals. I've been getting by all these years with a cheapo pair of stamped metal crimpers and the cheapest crap terminals available. No more!
I just ordered a set of hex dies for $17 free shipping. I'll use them in my wife's mini hydraulic press (you put a standard 10 ton hydraulic jack in it). One review said he preferred a sledge and anvil approach. I'll post a review once I give them a try.

The closed end lugs I bought from Current Connected are tinned. I really don't have much an opinion either way on open vs closed. It's starting to sound like which is better - Republican or Democrat? LOL. I may have my strong opinion - and it's not as one-sided as you might think, as both versions have pros and cons.
 
I have been twirling my cable to get them into the lug. Yeah, nah?

As with soldering, Ive been soldering all my 50A Anderson plugs. I havent had any failures. They are years old!
 
Big wires, I do. I use a small length of copper tube, soak both the wires and the tube with (proper) solder, insert the ends, give it a few bangs with a cold chisel - on wood, heat with blow torch, give it a few more bangs.
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PV, has anyone done a resistance test between the two?
I've been searching for a paper, but just come up with 'received wisdom' from other forums - it's as bad as twatter!

It does however make sense that cold welding (bonding at the atomic level) gives a better electrical connection than wetting the copper with tin/lead.
 
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I've been searching for a paper, but just come up with received wisdom' from other forums - it's as bad as twatter!

It does however make sense that cold welding (bonding at the atomic level) gives a better electrical connection than wetting the copper with tin/lead.

Why bother. Please crimp your cables and wire terminals, cuz that's what's best.

A quick search revealed:




 
Why bother. Please crimp your cables and wire terminals, cuz that's what's best.

A quick search revealed:





Great article.

Well I’m disappointed. I have many soldering irons and an 80w unit yet to arrive! But really I mostly use them to join two wires. The only soldering I have been doing mostly to crimps is with the Anderson plugs.

So I will crimp and properly. At least I had this right. For crimps exposed to the weather I will still add amalgam tape.

Thanks for the very informative education guys.
 
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.
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Don’t solder crimps. It’s not a good idea. Just do the crimp correctly in the first instance
 
There are advocates for 'die-less' crimping - because if the die doesn't fit exactly right it could be too tight causing ridges or deformation, or worse - too loose. The exact die, or a die matching your lugs, like you might get from Temco, is sure a great way to go, if not the most costly as well. If I was doing a lot of this type of work I would surely have the fancy Temco one with all the dies and their matching lugs. For a one-off, their hammer crimper does a nice job - hammer the crap out of it, it welds it. LOL And yes on the adhesive lined 3M shrink tubing - the only way to go for this stuff.
If I were doing a LOT of crimps, it would make sense to use the best tool reasonably possible, such as the $175 Temco set. But for my needs, a few crimps a year is probably all I will ever do, unless I get into DIY solar big time.

I just received a $17 hex crimp die set, which is for mm2 not AWG and we'll see how well it crimps or not soon. If poor, I also have the Temco hammer crimper as a backup (I will return one tool soon, I don't need both). I certainly won't be using a die that's too big, hence too loose of a crimp, but the worst thing I can see with a die that's just slightly too small is the creation of some 'wings' on the sides of the crimp where the two halves of the die meet. Shrink and perhaps a gentle filing to remove any sharp edges would fix that.
I also came to realize that many, if not most, tinned lugs are open, whereas the copper ones were closed. Frankly I like the closed end, and with a shrink wrap on there they are well sealed.
The lugs I just received from Current Connected are tinned and closed. Compared to the copper non-tinned closed lugs I recently purchased from a NAPA auto parts store, they seem as good if not better in terms of thickness and construction. NAPA charged $4.50 per lug for 1AWG and Current Connected charged $2.75 for 1/0AWG, but you do have to pay for shipping (which was SUPER fast).
There are advocates for soldering, but there are just too many cons, not to mention the 'work hardening' that happens where the soldered strands meet the unsoldered strands in the wire, in a mobile application. AFAIK aircraft and military assembly requires everything to be crimped.
Yeah, I'm just done with ever trying to solder battery and inverter cables again. I clearly had the wrong technique, solder and/or flux and it made a mess oxidation-wise of very expensive cable and lugs. Just not worth it when crimps are considered the gold standard by outfits like the military.
 
This is why everyone says crimping is the way to go.
No not everyone. I say crimping is the way to go because the end result is a low ohm, permanent connection that cannot fail without aggressive destructive intervention.
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?
Dielectric- the “die-“ part means it’s resistive to electrical conductivity. You want clean, dry crimps. Use dielectric grease or fluidfilm after the electrical connection is assured to lock out oxygen on the exposed area
What’s dangerous about this kind of crimp?
It is not 100% contact over the full body of the terminal cavity. Higher ohms; resistance makes heat, heat causes fires. Never mind poor performance- at the price of copper just spend it and do it right.
I mean there are hammer style crimpers, what’s wrong with this redneck version
The hammer-style crimpers are dubiously effective on just one or maybe two sizes of terminals. Plus, the die crimpers have a huge advantage (that is marginally the reason why the hammer crimpers sortof work dubiously for 1ga, 1/0ga, and 2/0(barely)): they swage the fitting barrel smaller than its manufactured shape and size. The hammer crimp crushes the fitting even sometimes stretching it. This is not 100% contact. When I use the hammer crimper I actually crimp in a few ‘stages’ to theoretically force the fitting to fold in itself before finally crushing it shut making a swage-like fit. But it’s not ideal for sure.
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
That is the best summary comment on this thread
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
As above!
struggling with the thought that a soldered joint isnt as good as a crimp. More contact area with solder.
Contact area is great; low resistance is another leg of the three-legged stool
never thought about (marine grade/glue lined) heat shrink helping keep moisture and air out.
Imho that is the primary reason to use it
I like the closed end, and with a shrink wrap on there they are well sealed
Because you like stuff done well
with a die that's just slightly too small is the creation of some 'wings' on the sides of the crimp where the two halves of the die meet. Shrink and perhaps a gentle filing to remove any sharp edges would fix that.
I seldom crimp in one stroke, but I start the swage, and rotate 90* and even ‘odd’ fittings don’t get the wings.

I’ve always been an annoying advocate of 100% contact. A former employer was irritated that I didn’t use the heat-shrink crush crimp terminals but used bare crimps and heat-shrinked over that. But with winter road salt and summer CaCl on dirt roads I learned a long time ago what worked. Years ago a broken spring event wrecked a boat trailer’s wiring and I quick fixed it roadside with a piece of extension cord and bare crimp butt-connectors, and heat shrink over. It’s been 15 years of a lot of wet cycles and it’s still going well-I never “fixed it.”
 
The hammer-style crimpers are dubiously effective on just one or maybe two sizes of terminals. Plus, the die crimpers have a huge advantage (that is marginally the reason why the hammer crimpers sortof work dubiously for 1ga, 1/0ga, and 2/0(barely)):
This is good to know. I ordered a hammer crimper but didn’t end up using it. I ordered also a die set and used my mini hydraulic press (uses a regular 4T jack) and this worked great.

My intent of my OP was that since we spent under $1k on our solar system, we didn’t need the $200 special tool to do 2 crimps. Some of you have built entire off grid homes with tens of thousands of dollars of equipment and dozens of large gauge connections, so higher end fittings makes sense there.

A $16 die set ended up being all I needed, very nice crimp. But the critical replies here helped me realize that while my original redneck two screws, tape, rock and sledge MIGHT be just fine (it did work fine, no heat or other issues) it’s not really a very safe way to do it or recommend to others to do it that way either. So I edited it to correct my mistake.
 
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