Making Battery Cables for Inverters

[MtnDon]

Bruce,

I thought the #2 would work as my calculator came up with 3.56% on an 11 foot distance. But the inverter sure did not like it.

The wire was salvaged from an old arc welder. I don't recall the brand and the cable markings only indicate voltage rating and wire gauge. Thinking real hard it might have been a Century... red like Lincoln and made in USA. Anyhow the 2/0 works like a champ! I'll hang onto the #2 for some lesser demand someday.

[Dale M.]

Need special crimping tool? Nah, just a copper connector, sledge and hammer. Shove the wire all the way into the connector, tape the connection together. Place on the sledge head, tap the copper connector with the hammer until it crimps the wire good. Remove damaged tape, check connection, and re-tape.

Always, always use a fuse or breaker sized for the lesser of the wire or equipment. That way, the worse thing you can do is let the smoke out of the breaker or fuse... Not the wire or equipment.

If that is only method you have then don't bother.... It's the poorest thing one can do and will only cause you grief later, at worst possible moment....

At least spend a few dollars and get something like this...



It will give you better crimp integrity similar to image below...



And use good silicone dielectric grease inside connection to prevent oxidation and corrosion...



Dale

[citylights]

Dale

Hey! My vice has a groove on the back of it just like that shape. No built in punch though. I bet that is what the groove was intended for, and now that all my leads are made up, I know.

[MtnDon]

Groove shape in a vice jaw is more likely for use with holding something round like a length of pipe

[bdosborn]

I couldn't find anyone on the internet (that seemed to know what they were talking about) with anything good to say about hammer crimps when I was looking at lugs to make cables with. Yes it will work but it doesn't seem to be much better than beating on it with a hammer. However, I did find that the subject of crimps to be a pretty volatile topic, kind of like how often you should change your oil.

Big RV Forum Arguing about lugs

A real compression tool for cable lugs is expensive:


and makes a connection like this, one solid lump of copper:


Making up Crimp Lugs

That's why I posted links to the Magna compression and solder lugs in the OP; I was hoping is was a better alternative to using a tool that doesn't seem to work well for a lot of people:





That being said, I did have one of the solder lugs pull apart so I'm not sure what I would use now that it's been a couple of years later. I had a spare solder lug that I replaced it with and haven't had any problems since.

Bruce

[MtnDon]

I've used the Magna type compression lugs once and they do seem to work well.

I don't really like soldering large gauge wires as getting the copper wires hot enough to accept solder properly melts/burns the insulation. I cover it with shrink wrap but then I also don't like using solder in critical connections as solder has a higher resistance than the copper.

I have a tool similar to the one at the end of this link.
My tool goes to AWG 0, and was about $100 years and years ago. That one goes to 2/0 and is $75 with shipping.

Is it affordable/reasonable? That is a matter of perspective. I think the usefulness of a decent tool for up to $75 can pay for itself over time.

For larger wires I had some dies made for use in a hydraulic press; AWG 2/0 and 4/0. It's just not very portable.