Grease vs Anti-oxidant compound

[Cruzer4326]

I'd like to shed some light on a previous discussion about putting grease/conductive grease on battery terminals.
First of all, Grease should never be considered. Period.
What is happening to our battery terminals is an oxidation problem-not a lubrication problem.
There are products available that are designed to inhibit oxidation on electrical terminals.
I have worked in various electrical fields from the rebuilding of starters and alternators, to rewinding electric motors and for the last 29 years I've been an electrician.
I have a Master Electrician license which is irrelevant in this discussion but I want you to know that I have some credibility.
What needs to be applied to our battery terminals is an Anti-Oxidant compound. There are several different types and many manufactureres.
Battery terminals differ slightly from manufacturer to manufacturer. Lead is the most common metal used in the US for top post batteries. I've seen Foreign (to US) manufacturers use a different alloy for their terminal clamp but from my limited experience, it really doesn't matter much the alloy used.

I have driven GM vehilces for over 45 years with the beloved side post batteries. I have had great success with using a product called Noalox, made by iDeal. It's made for terminating copper wires into aluminum terminals. Never a failed start when a small portion was used.
There is another product called Copper Cote, which is actually an anti-sieze compound, but it will do the same job but from my experience with it it will tend to thicken over time.
Please do your own research and find the type of anti-oxidant compound that give you the feel-goods, but PLEASE don't use grease on your electrical terminals.
As far as the torqing/over-torquing of your clamp style terminals, Observe the recommended specs. Having said that, If you can move the terminal with your hand (twist, turn, pull off) it's not tight enough and no anti-oxidant compound will help you. The terminals must be tight to conduct electricity properly.
I hope this will help some of you who are not clear on this issue, I want to help you.

 

[Bailes1992]

Also an electrician here. We use jointing compounds where we are joining dissimilar metals I have too used it on battery terminals with good success.

I clean our engine bays every 6 months, during that clean I visually check the battery terminals for any corrosion and check they are tight before adding a small squirt on each terminal of Bilt Hamber Ferrosol. Never had any issues at all.

 

[kschachn]

Dielectric grease is both adequate and appropriate for the battery terminals. It excludes water from the connection and prevents corrosion.

You do NOT want a conductive compound.

 

[Cruzer4326]

Also an electrician here. We use jointing compounds where we are joining dissimilar metals I have too used it on battery terminals with good success.

I clean our engine bays every 6 months, during that clean I visually check the battery terminals for any corrosion and check they are tight before adding a small squirt on each terminal of Bilt Hamber Ferrosol. Never had any issues at all.

Awesome!! I'm happy that you could suggest some type of product that is available across the pond. I often forget that this forum is world-wide, and I'm a little new here.
It's so cool to hear of a fellow tradesman from the UK! I suspect we would have a lot to talk about out trade. About the similarities and differences in our craft, mostly due to voltage differences and code requirements.

 

[Cruzer4326]

Dielectric grease is both adequate and appropriate for the battery terminals. It excludes water from the connection and prevents corrosion.

You do NOT want a conductive compound.

This is taken from the online encyclopedia Brittanica;
dielectric, insulating material or a very poor conductor of electric current. When dielectrics are placed in an electric field, practically no current flows in them because, unlike metals, they have no loosely bound, or free, electrons that may drift through the material. Instead, electric polarization occurs. The positive charges within the dielectric are displaced minutely in the direction of the electric field, and the negative charges are displaced minutely in the direction opposite to the electric field. This slight separation of charge, or polarization, reduces the electric field within the dielectric.
The presence of dielectric material affects other electrical phenomena. The force between two electric charges in a dielectric medium is less than it would be in a vacuum, while the quantity of energy stored in an electric field per unit volume of a dielectric medium is greater. The capacitance of a capacitor filled with a dielectric is greater than it would be in a vacuum. The effects of the dielectric on electrical phenomena are described on a large, or macroscopic, scale by employing such concepts as dielectric constant, permittivity, and electric polarization.


Are You sure about your comment?

I respectfully disagree with you, sir.

 

[kschachn]

I do know what I’m talking about yes. But you don’t understand how electrical terminations are made. No current flows through a dielectric regardless of whether it is air or grease or any other compound. Current flows through the metal-to-metal contact. Once that is made the dielectric is irrelevant and only exists to exclude contaminates from the joint.

If there isn’t proper metal-to-metal contact then the termination will be poor irrespective of the dielectric. Air is a dielectric and works exactly the same as grease if proper contact isn’t made.

 

[Bailes1992]

I do know what I’m talking about yes. But you don’t understand how electrical terminations are made. No current flows through a dielectric regardless of whether it is air or grease or any other compound. Current flows through the metal-to-metal contact. Once that is made the dielectric is irrelevant and only exists to exclude contaminates from the joint.

If there isn’t proper metal-to-metal contact then the termination will be poor irrespective of the dielectric. Air is a dielectric and works exactly the same as grease if proper contact isn’t made.

Agree with this and missed the point the OP was making.

You make the connection with clean, dry terminals and then apply grease or your chosen product afterwards. This is to suffocate the joint and stop oxygen getting to it. No oxygen, no oxidisation.

 

[kschachn]

Agree with this and missed the point the OP was making.

You make the connection with clean, dry terminals and then apply grease or your chosen product afterwards. This is to suffocate the joint and stop oxygen getting to it. No oxygen, no oxidisation.

Yes but a grease will be displaced from the connection exactly like any other dielectric once proper contact is made. It’s really no different from air or even a vacuum. No contact, no conduction.

Dielectric greases are extensively used in sliding contacts such as a pin and socket to reduce mating friction and fretting. A battery terminal is the same.

 

[Bailes1992]

Yes but a grease will be displaced from the connection exactly like any other dielectric once proper contact is made. It’s really no different from air or even a vacuum. No contact, no conduction.

So you're suggesting applying grease and then making the connection? I actually can't see any issue with that.

I suppose it's no difference to filling any other connector up on the car with some dielectric grease before termination to stop water etc getting in. As I do with every other connection on the car.

 

[wpod]

Agree with this and missed the point the OP was making.

You make the connection with clean, dry terminals and then apply grease or your chosen product afterwards. This is to suffocate the joint and stop oxygen getting to it. No oxygen, no oxidisation.

Cept the corrosion is caused by battery acid in this case not so much the oxidation in the atmosphere

 

[kschachn]

So you're suggesting applying grease and then making the connection? I actually can't see any issue with that.

I suppose it's no difference to filling any other connector up on the car with some dielectric grease before termination to stop water etc getting in. As I do with every other connection on the car.

Yeah. It has the added benefit of filling the interstitial area where there is no contact and can help to exclude moisture or other contaminants from reaching the metal surfaces. If water intrudes it will cause corrosion and generally corrosion compounds are less dense than the base metal, so they tend to force the connection apart causing reduced conduction. I’m sure you know you can have even a clamped joint corrode completely apart.

 

[Cruzer4326]

I do know what I’m talking about yes. But you don’t understand how electrical terminations are made. No current flows through a dielectric regardless of whether it is air or grease or any other compound. Current flows through the metal-to-metal contact. Once that is made the dielectric is irrelevant and only exists to exclude contaminates from the joint.

If there isn’t proper metal-to-metal contact then the termination will be poor irrespective of the dielectric. Air is a dielectric and works exactly the same as grease if proper contact isn’t made.

Perhaps we are splitting hairs here.
Any electrician worth his salt understands clearly that the electrical connection is made with the actual metal to metal connection. That's extremely basic and I admit that I didn't think that would need to be explained. That's not addressing the topic which is corrosion.
Having said that, if you choose to use a dielectric to fill the voids and small gaps to control the corrosion, I hope you are using it quite sparingly.
IF one uses and Anti-Oxidant compound, which addresses the actual problem, the compound will fill all the voids as the connection is tightened, suffocating the oxidation issue as well. Also not needed in large quantities.
I know of an old timer electrician who successfully used a thin bead of RTV just below the cable clamp. (Top post). RTV is quite a good dielectric, I admit. I could not recommend this because human nature often reflects that if some is good and more is better- not so in this instance.
You use your Dielectric grease the way you want to, I'm sticking with my anti-oxidant compound.
That dielectric air will still allow oxidation, which again I say is the issue.
If anti-oxidant compound is used lightly during the assembling of the cable terminal it is Squished out filling possible air voids and, due to it's anti-oxidant properties, keeps the connection from corroding, where dielectric air voids could not.

 

[kschachn]

Most common RTV are acetic acid cure and are inappropriate for electrical connections. I hope your friend was using an oxime or alcohol curing RTV.

And sure you can use a dedicated joint compound if you wish but it’s not necessary here, and neither are the grand warnings you gave in your opening post.

Excess dielectric is irrelevant for the joint. It causes dirt accumulation or other problems due to grease migration but it will not affect the joint.

 

[sk_pete]

Cept the corrosion is caused by battery acid in this case not so much the oxidation in the atmosphere

umm, (sanded) silvery lead goes to grey.
how it´s done? no acid leaks, battery intact.

 

[brianl703]

Most common RTV are acetic acid cuing and are inappropriate for electrical connections. I hope your friend was using an oxeme or alcohol curing RTV.

And sure you can use a dedicated joint compound if you wish but it’s not necessary here and neither are the grand warnings you gave in your opening post.

Excess dielectric is irrelevant for the joint. It causes dirt accumulation or other problems due to grease migration but it will not affect the joint.

This electrican must not have ever seen the wirenuts that come from the factory filled with....silicone dielectric grease.

 

[kschachn]

umm, (sanded) silvery lead goes to grey.
how it´s done? no acid leaks, battery intact.

No leaks is best of course. But you can help to keep the acid away from the joint and terminal body by using a suitable grease.

 

[sk_pete]

lead is not noble metal.

Lead is soft and malleable, and also has a relatively low melting point.
When freshly cut, lead is silvery with a hint of blue; it tarnishes to a dull gray color when exposed to air.

 

[Cruzer4326]

Dielectric grease is both adequate and appropriate for the battery terminals. It excludes water from the connection and prevents corrosion.

You do NOT want a conductive compound.

Please explain why "You do NOT want a conductive compound".

 

[kschachn]

Please explain why "You do NOT want a conductive compound".

Current density is one thing as well as grease migration. You want the starting current to pass through the metal terminal connection itself not some alternate path with unknown conductivity and reliability. You really never want this but at low current density with poorly designed or damaged terminals you can get away with it. You want the starting current to go through the joint as designed.

All greases and lubricants can migrate. You don’t want stray current paths.

 

[kschachn]

lead is not noble metal.

Did someone say that it was?