Solder Battery Cable to Lug?

[powerscol]

Note to the Forum: I created this new thread from posts in the "Show Me Your Battery Box" thread as I thought the topic of soldering deserves it's own conversation. -Howard

Strange folks say not to solder. On my old unit I soldered up all the lugs with no issue. I used shrink wrap over the soldered connection (color coded).

To solder I used a vice to hold the cable vertical with the fitting on the lower end against a piece of cement board, This minimized the amount of solder running along the cable as would happen if soldered sideways. I cleaned and fluxed the inside if the lug fitting (all brass) with emery cloth, and just the tip of the marine grade cable. Used map gas in a portable torch. Used proper electric solder an filled the fitting to the top.

Never had an issue. Might be good to have more of a discussion on why I should not have done this for the future.

[J&G garage]

Crimp and solder is good. But relying on solder only not so much. An over heated connection can cause the solder to melt and release the cable from the terminal possibly creating a short circuit. If also crimped the connection will remain intact.

[Chiefblueman]

Strange folks say not to solder. On my old unit I soldered up all the lugs with no issue. I used shrink wrap over the soldered connection (color coded).

To solder I used a vice to hold the cable vertical with the fitting on the lower end against a piece of cement board, This minimized the amount of solder running along the cable as would happen if soldered sideways. I cleaned and fluxed the inside if the lug fitting (all brass) with emery cloth, and just the tip of the marine grade cable. Used map gas in a portable torch. Used proper electric solder an filled the fitting to the top.

Never had an issue. Might be good to have more of a discussion on why I should not have done this for the future.

The main purpose of solder is to fill all the tiny voids in an electrical connection, decreasing resistance and "sealing" the connection, not mechanical strength.

[powerscol]

Learned something new - Thanks

Now at my age that means I will forget something now

[J&G garage]

Got same problem. Something goes in, something else has to go out🙂

[Cate&Rob]

Crimp and solder is good. But relying on solder only not so much. An over heated connection can cause the solder to melt and release the cable from the terminal possibly creating a short circuit. If also crimped the connection will remain intact.

The problem with a soldered connection is not the solder . . . it is the remaining flux. You end up with a connection coated in a corrosive acid. I have seen the situation where the remaining flux corroded the terminal to battery post connection. This caused resistive heating and the solder melted. The cable literally fell out of the terminal.

Rob

[powerscol]

Maybe I have missed something. There are too fluxes out there. The typical pluming one is highly acidic to etch the brass piping and you must use the pluming grade solder -AND- the electrical one that I use is not (at least I think so) and is compatible with the rosin core electrical solder. On must be careful to not mix the two as things tend to fall apart as Rob has mentioned. The other thing is most marine electrical wiring is pre-tinned to minimize corrosion so less flux is needed.

Just my thought on this
Keith

[phonemannn]

First of all, Do NOT solder the lugs on. Heat (current flow through the wires) can be your enemy with soldered lugs. Crimping is the accepted standard! Here is a link to Amazon where there are a lot of crimping tools available. Just be careful though and make sure that the ones you consider are large enough to handle the size wire/lug combination that you will need to crimp. I normally recommend a high quality tool in most instances, but for very occasional use, some of the cheaper one would probably serve you well.....

https://www.amazon.com/s?k=wire+crim...f=nb_sb_noss_1

Dont know where you are coming from, soldering on terminals is the best way to go.
https://www.google.com/search?source...31.jl8vB-0HDV4

[xrated]

Dont know where you are coming from, soldering on terminals is the best way to go.
https://www.google.com/search?source...31.jl8vB-0HDV4

Where I'm coming from is being a Journeyman Electrician for the past 39 years with lots and lots of experience working with everything from 20ga wires all the way up to 1000 MCM high voltage cables. A properly crimped connection is the preferred method of joining the lug/connector to the cable or wire, especially in an environment that is subject to vibration and or movement....as in a travel trailer going down the road.

[phonemannn]

Where I'm coming from is being a Journeyman Electrician for the past 39 years with lots and lots of experience working with everything from 20ga wires all the way up to 1000 MCM high voltage cables. A properly crimped connection is the preferred method of joining the lug/connector to the cable or wire, especially in an environment that is subject to vibration and or movement....as in a travel trailer going down the road.

A lot less resistance with a soldered connection. I guess if both done correctly, Either is good. I am an retired electrical engineer, so similar resume. I guess the big variable here is "done correctly" I always liked soldering over crimps, but some mili spec stuff demands crimps.. but must be done correctly. At this voltage/ amperage I don't see heat being an issue using either method. IMO.