Trojan short T105 terminals

[Wotname]

Originally Posted by Wotname

Well Ron is entitled ...etc

Opps, my bad, I meant to type Rod -

[ramblinrod]

Originally Posted by Wotname

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)

Shucks, you referenced the post before I decided to take it down.

Hint: Don’t forget about the load.

[daletournier]

Originally Posted by 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.

Hang on, you must live in the real world!

[DotDun]

Rod,

Why don’t you test your theory!

Put a fiber washer between the nut and lug. Add a 100A load, measure the voltage at the load. Remove the fiber washer, retest. Let us know the voltage at the load with washer/no washer.

[transmitterdan]

A fiber washer will most likely get crushed by the pressure and you won’t get an accurate result. The only way to make the right pressure is to use steel or something with the same properties as steel. Nothing made of fiber I know of will do that.

BTW, this is another somewhat common thing i see where someone uses a piece of fiberglass as one side of a high current connection. It won’t last because the fiberglass creeps and relieves the pressure on the joint. Then heating goes way up. Sometimes it takes weeks or months for it to happen.

[transmitterdan]

Look back at the most recent picture in this thread of the binding post. Notice it has 2 nuts and lugs go between them. The nuts press the lugs together. No current in the nuts or the threaded rod.

Question: Why don’t battery studs come with 2 nuts like that?

Answer: Because the small threaded post cannot handle the high battery current. It would have to be much larger in diameter. Plus the battery would take more vertical space.

[DotDun]

It’s for a test. A fiber washer should take 30-40lbs of torque. Same torque with/without the washer. The point of the test is to see the voltage drop difference with zero current flowing thru the nut.

[ramblinrod]

Originally Posted by DotDun

Rod,

Why don’t you test your theory!

Put a fiber washer between the nut and lug. Add a 100A load, measure the voltage at the load. Remove the fiber washer, retest. Let us know the voltage at the load with washer/no washer.

Yeah, that would work. Go for it.

[Wotname]

Originally Posted by transmitterdan

Look back at the most recent picture in this thread of the binding post. Notice it has 2 nuts and lugs go between them. The nuts press the lugs together. No current in the nuts or the threaded rod.

Question: Why don’t battery studs come with 2 nuts like that?

Answer: Because the small threaded post cannot handle the high battery current. It would have to be much larger in diameter. Plus the battery would take more vertical space.

Presumably you are referring to the picture in post #43 rather than the most recent picture, if so I don't see any insulating material that would prevent current from flowing though the nuts or threaded rod.

If it isn't the picture in post #43, which post are you referring to?

[Wotname]

Originally Posted by DotDun

Rod,

Why don’t you test your theory!

Put a fiber washer between the nut and lug. Add a 100A load, measure the voltage at the load. Remove the fiber washer, retest. Let us know the voltage at the load with washer/no washer.

Originally Posted by DotDun

It’s for a test. A fiber washer should take 30-40lbs of torque. Same torque with/without the washer. The point of the test is to see the voltage drop difference with zero current flowing thru the nut.

Circuit analysis of this proposed test is straightforward and it tells us the voltage to the load will decrease, i.e. the voltage drop across the terminal will increase with the fibre washer inserted. This is due to the small increase in resistance of the terminal junction once the fibre washer is added.

The only thing a test will do is give us the relative change in values and I think we all agree that the changes will be very very small unless there is an unwanted high resistance component in the terminal to lug junction.

Please recall the determining factors are known as Kirchhoff's voltage and current laws, not Kirchhoff's voltage and current theory. There is a huge difference in the science community between a law and a theory.

[Wotname]

Now back to the OP .
Hey Dale, don't know if this makes you feel any better but I just saw this thread from some months back.
http://www.cruisersforum.com/forums/...ls-194028.html

[ramblinrod]

Originally Posted by john61ct

The*first*law of*holes in action.

Now is that the most intelligent thing you have to say?

[transmitterdan]

Originally Posted by Wotname

If it isn't the picture in post #43, which post are you referring to?

It was post 43. Sorry for misremembering.

[DotDun]

Originally Posted by Wotname

Circuit analysis of this proposed test is straightforward and it tells us the voltage to the load will decrease, i.e. the voltage drop across the terminal will increase with the fibre washer inserted. This is due to the small increase in resistance of the terminal junction once the fibre washer is added.

The only thing a test will do is give us the relative change in values and I think we all agree that the changes will be very very small unless there is an unwanted high resistance component in the terminal to lug junction.

Please recall the determining factors are known as Kirchhoff's voltage and current laws, not Kirchhoff's voltage and current theory. There is a huge difference in the science community between a law and a theory.

So, in real world applications, that very very small difference, that most DVMs would be challenged to measure, doesn’t have any impact. But some like to make it out as a Armageddon for nothing more than egotistical reasons.

[john61ct]

Originally Posted by ramblinrod

Now is that the most intelligent thing you have to say?

Sorry didn't see the asterisks, apparently the space characters converted to that, and some thought obscenities were implied.

I just meant, "if you find yourself in a hole, stop digging".

Too clever by half I see now, so again, sincere apologies.