Trojan short T105 terminals

[Uncle Bob]

Originally Posted by daletournier

Of course it can but that it's not the path the current takes, it runs from the lugs to the cables. If there's a problem this isn't due to nylocs or loctite, this is due to poor maintenance at the terminals or loose connections . As mentioned by John the nuts could be completely non conductive. Their job is to fasten the conductive lugs to the battery not act as conductors (a path) for current to run through.
We are now going around in circles.

Dale, FFS will you please stop being so damn logical, you need to get with the program.

[john61ct]

Originally Posted by ramblinrod

the purpose of the test was to prove that Loctite between the threads increased contact resistance. The protocol was adequate for that purpose.

No one questioned that it would.

Just that, the fact it does is irrelevant.

> significant current can be passed between a threaded post and nut, which confirms my hypothesis and rejects any notion that current cannot follow this path as a number of you have posted.

I never noticed anyone claiming "cannot".

Simply that it does not.

Conductivity is simply not needed wrt the nut. It's role is simply as a fastener.

[john61ct]

Originally Posted by ramblinrod

if there is corrosion under the lug

then the owner is not properly maintaining their system.

All kinds of bad things happen when that is the case, not least a higher risk of battery explosions.

Fact that both CALB and Maine Sail think it's OK, and especially in the context of the OP's need, IMO we've definitely gotten into very silly digging in of heels to not admit a minor error.

If your desire is to recover/maintain your overall credibility, other approaches would be more helpful.

______
Do you still stand by your statements made when first joining here, along the lines of:

big-box 12V batts are just as good as 2V/6V units designed for deep cycling

in fact, no such thing as true deep cycling batts, one's just as good as another

lots of big-box 12V batts paralleled are better than serialing 2V/6V batts in building up large house banks

?

[ramblinrod]

Originally Posted by hzcruiser

That doesn't make John's and .Dun's statement about the "possibility" of the stud being made of non-conductive material wrong, though.

Never said it was.

[ramblinrod]

Originally Posted by john61ct

> significant current can be passed between a threaded post and nut, which confirms my hypothesis and rejects any notion that current cannot follow this path as a number of you have posted.

I never noticed anyone claiming "cannot".

Simply that it does not.

Conductivity is simply not needed wrt the nut. It's role is simply as a fastener.

1. Marine battery posts are conductors, not insulators.

2. Current DOES flow through the stud and nut in every normal circumstance.

3. This can be important to operation, in the event of a high impedance connection, which is quite common.

4. I believe that all marine battery posts are made of conducting materials for this very reason.

Anyone wishing to buy a battery with insulating posts, if they could find one, is free to do so.

However, I wouldn't recommend it, for reasons stated.

[Sailmonkey]

Originally Posted by ramblinrod

1. Marine battery posts are conductors, not insulators.

2. Current DOES flow through the stud and nut in every normal circumstance.

3. This can be important to operation, in the event of a high impedance connection, which is quite common.

4. I believe that all marine battery posts are made of conducting materials for this very reason.

Anyone wishing to buy a battery with insulating posts, if they could find one, is free to do so.

However, I wouldn't recommend it, for reasons stated.

I have these on all of my battery posts. The stud is not a conductor.

[john61ct]

Too much dude, really beating that dead horse huh!

I never claimed posts are actually non-conductive.

As already stated above, the "post may as well be non-conductive" idea

is simply to illustrate the point that the couple of threads' nylon or a schmear of loctite won't cause problems, if an owner feels she has good reason to use them.

[ramblinrod]

Originally Posted by john61ct

Too much dude, really beating that dead horse huh!

I never claimed posts are actually non-conductive.

As already stated above, the "post may as well be non-conductive" idea

is simply to illustrate the point that the couple of threads' nylon or a schmear of loctite won't cause problems, if an owner feels she has good reason to use them.

You claimed there is no current flow through the post.

That was wrong.

[ramblinrod]

Originally Posted by john61ct

IMO we've definitely gotten into very silly digging in of heels to not admit a minor error.

Agreed 100%.

Let’s drop it?

FWIW, I don’t believe I’ve made any error or inaccurate statement in this thread.

[ramblinrod]

Originally Posted by Sailmonkey

I have these on all of my battery posts. The stud is not a conductor.

Correct!

It can’t be, else it would short circuit and negate any benefit of the fuse it is designed to carry.

In this case, an insulated post is a benefit.

But note that the battery terminal post it is connected to is not insulated, for good reason.

[john61ct]

Originally Posted by ramblinrod

You claimed there is no current flow through the post.

That was wrong.

Read more carefully

Originally Posted by john61ct

We're not attaching devices with alligator clamps to the outside of the nut.

Again, the contact area is between the flat "donut" surface at the batt body at the bottom of the post, and the wide surface of the lug.

The role of the post/bolts' and nuts' threading is simply to torque down and hold the lug tightly with maximum area against that surface.

There isn't current flowing "through" where the nylon is.

The post and nut could be completely non-conductive.

Originally Posted by ramblinrod

Agreed 100%.

Let’s drop it?

OK, if I get the last word. 8-)

You stop posting to this thread completely, so will I.

[ramblinrod]

I am posting responses to questions or statements I feel are incorrect, in accordance with forum rules, in my attempt to help fellow sailors improve safety and performance on their vessels.

Originally Posted by john61ct

I never noticed anyone claiming "cannot".

Simply that it does not.

WRT current passing through the threaded post and nut...

It "can", therefore it "does".

Originally Posted by john61ct

Conductivity is simply not needed wrt the nut. It's role is simply as a fastener.

In my opinion, post conductivity is "needed" if one desires to retain the design benefit of electrical circuits working when there is a high impedance connection between the battery lug and terminal base.

Many design elements perform more than one role.

In my opinion, the role of the threaded post and nut is to:

1. Enable lug connection to the battery.

2. Retain the lug in intimate electrical contact with the battery terminal base.

3. Conduct current to the top of the lug if it is not effective in role 2.

4. Enable lug removal from the battery.

If the nut supplied with the battery (millions if not billions sold) is adequately capable of performing these roles, modifying the design by the use of Nylocs or thread locker, may introduce problems (predicted and unforeseen) for no benefit.

Anyone wishing to do so may proceed. There is certainly no law against it.

However, I recommend reading your battery warranty carefully, regarding limitations based on actions of the user, especially the "no modification", clause.

Back to the OP.

The issue was insufficient thread engagement due to the thickness of lugs used.

Some solutions suggested were to use Nylocs or threadlocker.

The may work. Then again, maybe they won't.

The Nylon insert of the Nyloc may not become engaged with the thread and will serve no purpose.

The Nylon insert may soften and or melt with temperature increase, rendering it less effective.

The thread locker may not provide sufficient turning resistance as compared to threads that should be engaged and aren't.

Then again, the thread locker may work so well that when the nut is removed it breaks the battery terminal post internal connection.

Again, I don't fault the OP for doing what he did, if it was truly an emergency, and no better solution was available.

If the correct solution (in my opinion, and as recommended by another "pro", and as supported by ABYC) was available, then the applied solution may have needlessly risked safety and performance.

That a different "pro" recommends use, or a single manufacturer provides a pre-doped Loctite (which is not likely the Loctite formula in question), is pretty much a moot point, in my opinion.

Again, no law against it, but one should always be aware of the risks associated with any electrical system modification they perform.

There is a certain assurance, the system will be safe, if one follows the appropriate electrical standards.

This is potentially lost, whenever one deviates, even if it seems to the common person, to be perfectly alright.

So in conclusion, my recommendation to the OP, and anyone still following is, always follow the appropriate electrical standards.

If you chose not, it is your skin, not mine.

[Wotname]

Originally Posted by ramblinrod

I am posting responses to questions or statements I feel are incorrect, in accordance with forum rules, in my attempt to help fellow sailors improve safety and performance on their vessels.



WRT current passing through the threaded post and nut...

It "can", therefore it "does".



In my opinion, post conductivity is "needed" if one desires to retain the design benefit of electrical circuits working when there is a high impedance connection between the battery lug and terminal base.

...................

Well Ron is entitled to his opinion but for anyone who has a different opinion on this subject should revisit their knowledge of Kirchhoff's voltage and current laws.

They will find that Ron and Kirchhoff are in complete agreement regarding this matter. If after reviewing what Kirchhoff has to say, they still want to voice their opinion that current doesn't flow though the post and nut, well IMO, their opinion doesn't matter.

Of course the relative values of current will determined by the relative resistances of the parallel current paths. Now you need to involve Ohm's law.

All of this is a long winded way that Ron is right about his claims of this aspect and he is supported by the masters of electrical understanding.



And oh, by me as well

[transmitterdan]

I have seen lots of battery terminal connections that were "corroded" between the lug and battery. In every single case it was corroded between the lug and the nut too. I have never seen a case where the lug/battery interface was corroded and the lug/nut interface was pristine and happily carrying all the current as is being suggested. Also, when corrosion happens invariably the overall joint becomes loose due to erosion of the metal layers. That's mainly what gets them hot.

Rod is right that some current flows in the nut. But it is such a small percentage as to not make any practical difference. So all this rambling about nuts carrying current is so much hogwash Kirchhoff is turning in his grave. Yes the nut can carry some current. It can carry about 10% of the lug/battery connection before it overheats. Even so, the nut is not needed to carry the battery current. It may as well be an insulator for all the good it does. It's job is to put pressure on the connection and nothing more than that. So long as it does that the joint will be as good as it can be.

[Wotname]

Originally Posted by ramblinrod

Sometimes even pros disagree.

Can you please site your evidence that the post only carries 10% of the load?

What happens if the lug to terminal contact resistance is 0.10 ohms, and the lug to nut contact resistance plus nut to post resistance is 0.10 ohms?

(PS, I already know the answer.)

You will get 2.5 V drop across connection and 125 watts of heating if you have a current flow of 50 amps and a nominal 12 V battery.


And yes, I know you know that (so does TxDan I reckon)