Choosing 4/0 welding wire or fine strand wire

scheek

I am going to make my own battery cables and I need some advice. Which wire is better and which is easier to work with to hold ends.

I am looking at welding wire vs the copper stand. If the out come is about the same I will go the cheaper route. I have found some for as low as (welding) $4.00 per foot vs $9.00 per foot for the copper fine strand.

Thanks,

Blackcherry04

Re: Choosing 4/0 welding wire or fine strand wire

Welding Cable works fine, using the proper crimp, using Tinned Lugs that fit the post your going to attach them to, using adhesive lined Heat Shrink all come into play on how good the cable is. As simple as it sounds, for some folks they do not turn out so good.

Wrong size lug for Post

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Wrong Heat Shrink, allowed wicking and destroyed cable

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scheek

Re: Choosing 4/0 welding wire or fine strand wire

What is a good crimper to use? Any other advice?

Blackcherry04

Re: Choosing 4/0 welding wire or fine strand wire

scheek wrote: »

What is a good crimper to use? Any other advice?

Thats a problem if it's for a one time use to do 4/0. There are all kinds of Hydraulic on E-bay, $50-$70 , make sure they have a 70MM die ( that'll do 4/0 ). I am not a fan of the hammer type, but they work ok.

http://www.solar-electric.com/nsearch.html?catalog=wind-sun&x=0&y=0&query=crimper

Sometimes you can search around town and get someone to do them.

zoneblue

Re: Choosing 4/0 welding wire or fine strand wire

If its just this one occasion, go to your local auto electrician and get him too crimp them, for a few beers. If theres even a vague chance youll need to make a second visit... the ebay import hydraulics will last your system out no worrys. I dont know about you, but bowing to the man with the tool sometimes just doesnt sit right

H2SO4_guy

Re: Choosing 4/0 welding wire or fine strand wire

I am using 4/0 for most of the battery cable (All of the bigger cells) and ends purchased from our sponsor (and some from evil-bay) and a similar shrink wrap that is sold by our sponsor. I have made cables for all 89 of the batteries in the electrical room. I have the hammer-crimper purchased from our sponsor, but I tend to like to solder them better. Off grid 100% of the time for 9 months so far and have never been without power since the system went in. It has expanded however. ;-)

mike95490

Re: Choosing 4/0 welding wire or fine strand wire

H2SO4_guy wrote: »

..... I tend to like to solder them better. ......

Bad choice. If there is ever a high current fault, solder joints can soften, melt and blow apart, making a wonderful mess.

Best is to use a hydraulic crimp tool in the 6-12 ton range. Around $100 on flea bay. Or the 36" handle crimpers from Greenlee, for $600. A good crimp fuses the copper strands together and into the metal of the barrel of the lug. A hammer/anvil crimper may only fuse 10% of the copper.

Solder wicks up into the wire, and makes a stiff point, where all the flex motion (even a few years of hot/cold cycles will flex wires) is forced to occur, and the strands will begin to break at that point.

There is still some controversy about this, and even though I am a solder guy, I bought a crimper for my battery wires.

https://www.highpowermedia.com/blog/3199/solder-or-crimp

zoneblue

Re: Choosing 4/0 welding wire or fine strand wire

There is a thread here where crimps and soldered lugs were tested:

http://forum.solar-electric.com/showthread.php?7629-Battery-interconnections&p=54715#post54715

Although he appears to have used the long handled crimper not a hydraulic crimper.

keyturbocars

Re: Choosing 4/0 welding wire or fine strand wire

I made quite a few 4/0 cables using the hammer type lug crimper. I tried the hammer method a couple of times, but I didn't like the way they turned out. I ended up using the crimp tool in a large, heavy duty vise to crimp the lugs and it was much easier to control and get more consistent and tighter crimps. The downside was that I needed to go to the shop to use the vise to make the cables. Measure, go to the shop to cut the cable and crimp the lugs, go back and install. A handheld hydraulic type crimper would be more convenient to use right at the site of the installation.

YehoshuaAgapao

Re: Choosing 4/0 welding wire or fine strand wire

I just bought pre-lugged wires. They were THHN (stiff). More than double the cost but unless you/installer has great tools and experience putting on these ends, you'll save overall (labor costs/time).

Cariboocoot

Re: Choosing 4/0 welding wire or fine strand wire

Might have missed something here but ...

Welding wire is fine strand (as opposed to multistrand) and is technically not allowed under code.

Be sure you know what your are getting and how it will be used.

Timinator

Re: Choosing 4/0 welding wire or fine strand wire

I took my 4/0 wire and ends to the local Welding supplier store. They put all my ends on for free.

zoneblue

Re: Choosing 4/0 welding wire or fine strand wire

The proper wire may be expensive, but it is double insulated, and you dont need much usually. Remember that battery cables are genreallly unfused so the more protection the better. Conduit definately recomended!