Automotive Battery Terminals

[amgent57]

I always remember the phrase,
"Clean, bright and tight"
when it comes to electrical connections.

Yet some say a very thin film of grease,
preferably dielectric, on the posts of automotive batteries.

Do you put them on dry or with a thin film of dielectric (or Vaseline)?

Vote!

 

[Farmall450]

Neither, I use the aerosol cleaner and protector.

 

[Chuckster in NJ]

X2 ^
I always use the proper product for the application after I clean the terminals with baking soda or battery terminal cleaner. Get the terminals clean and shiny, tighten them up and then apply a proper terminal protector. ALWAYS WEAR EYE PROTECTION when cleaning up battery terminals.

BTW! NO Grease of any kind or sticky products because they attract dust and dirt.

 

[mm08822]

Ummmm, dielectric = non-conductive. NO!

 

[dave*99]

Permatex recommends it be applied to battery terminals before assembly.

 

[Chilliwack Murray]

The dielectric properties of dielectric grease are more relevant at high voltage and low current so it is quite useful on spark plug boots to prevent arcing. The dielectric properties have little impact on a high current connection where it will burn away from the current carrying surfaces and doesn't really interfere with conductivity.

There are lots of different battery terminal sprays but most form a coating that builds up and is hard to remove making a mess over time. On large generators with anywhere from 2 to 12 8D batteries we use Fluid Film after cleaning and reinstalling the terminals. They also get cleaned and the process repeated every 6 months.

 

[Chuckster in NJ]

The dielectric properties of dielectric grease are more relevant at high voltage and low current so it is quite useful on spark plug boots to prevent arcing. The dielectric properties have little impact on a high current connection where it will burn away from the current carrying surfaces and doesn't really interfere with conductivity.

There are lots of different battery terminal sprays but most form a coating that builds up and is hard to remove making a mess over time. On large generators with anywhere from 2 to 12 8D batteries we use Fluid Film after cleaning and reinstalling the terminals. They also get cleaned and the process repeated every 6 months.

Every mechanic should have a can of Fluid Film "at the ready" to use…….. This has multiple uses and if you have snow equipment it is a must have.

 

[mm08822]

I agree with the ability to block moisture between post and terminal but I'd rather use a conductive paste/spray than an insulator. Understood that tightening a lug around the post can become lead-lead contact, but for the areas that don't fit tightly, I'd rely on a conductive media vs. a non-conductive media.

I used to use Penetrox to simply displace air and gas between those two parts. Always worked like a champ for 40+ years.

 

[Chuckster in NJ]

Looks like the OP's poll is DOA.

 

[BonzoHansen]

I've been using this for years

 

[dave*99]

Neither, I use the aerosol cleaner and protector.

Main ingredient is Petrolatum. In other words Vaseline. Grease.

 

[dave*99]

I've been using this for years

Another Petrolatum based product. Vaseline in a spray can. Grease

 

[BonzoHansen]

And zero terminal issues.

 

[dave*99]

Petroleum Jelly and Dielectric grease will have the same results on lead battery connectors and terminals. Unlike petroleum jelly, dielectric grease will not degrade certain rubber/plastic insulating materials.

Dielectric grease is silicone based. Petroleum jelly is hydrocarbon based.

 

[dscheidt]

The dielectric properties of dielectric grease are more relevant at high voltage and low current so it is quite useful on spark plug boots to prevent arcing. The dielectric properties have little impact on a high current connection where it will burn away from the current carrying surfaces and doesn't really interfere with conductivity.

There are lots of different battery terminal sprays but most form a coating that builds up and is hard to remove making a mess over time. On large generators with anywhere from 2 to 12 8D batteries we use Fluid Film after cleaning and reinstalling the terminals. They also get cleaned and the process repeated every 6 months.

The important bit about dielectric grease is that when it burns, it doesn’t leave a conductive carbon soot track. Petroleum greases do, so once arcing starts, the grease makes it worse.

That matters not at all for battery terminals. You only care about corrosion protection, really.

 

[Junkman]

How about KY jelly? It doesn't harm rubber parts!

 

[InsanePyro]

And zero terminal issues.

You're running head first into the point and still missing it

 

[badmatt]

I dont use anything on electrical terminals.

Only time I use dielectric is on seals of connectors.

 

[joe_padavano]

The dielectric grease squeezes out when you tighten the terminal and the resulting squeeze-out forms a barrier that protects the mating surfaces from corrosion. Don't overthink this (oh, sorry, I forgot that this IS the interwebs...). I've been doing this for decades.

 

[theoldwizard1]

Do you put them on dry or with a thin film of dielectric (or Vaseline)?

Old school. Big gob of Vaseline AFTER you install the battery terminal clamp.

Here is why. The "white crusty" stuff that you get around the posts and on the clamps is from gases leaking from inside the battery around the posts. A good "gob" of grease/Vaseline prevents the gases from escaping !

Those fancy felt washers that you put under the clamps do the same thing !

 

[Farmall450]

Main ingredient is Petrolatum. In other words Vaseline. Grease.

Yeah, but it's not sticky and remains clean.

 

[micromind]

I've used those red and green felt battery washers for years, they work well.

I haven't seen them in a long time though, I don't know if they're still made or not.

 

[Jeepster04]

Most of mine are dry, nothing. If I notice any sort of corrosion then I'll address it. On my vehicles, I use the little pad things that go around the post/under the battery terminal. I dont like spraying **** on my batteries.

If its something I dont care about but Im worried about corrosion, I'll use the pads and spray (Noco).

I've never had corrosion issues on my Jeeps but for some reason, my dads Nissan is constantly a science experiment. Both the stock battery and the Costco Interstate battery have caused issues. His car gets the pads and spray. He someway lost one of the pads last time he changed his battery though....

 

[wyliesdiesels]

I use the battery terminal protector spray that several people listed. this prevents battery acid from corroding the battery cable clamps

I also spray it on top of the battery to prevent any seeping acid from travelling on the battery case towards the terminals.

 

[wyliesdiesels]

I've used those red and green felt battery washers for years, they work well.

I haven't seen them in a long time though, I don't know if they're still made or not.

yes theyre still made. Oreilly auto zone and amazon sell them. I keep a baggy of them in my toolbox

 

[wyliesdiesels]

Another Petrolatum based product. Vaseline in a spray can. Grease

but there is an ingredient that causes it to stick to the surface and when dry, does not collect dust unlike grease....

 

[dave*99]

but there is an ingredient that causes it to stick to the surface and when dry, does not collect dust unlike grease....

Understood. But the survey is binary. Choose grease or dry. Or abstain?

 

[mervyn]

I only use the best bacon grease.

 

[mervyn]

But seriously I've never used any kind of grease on battery terminals

 

[whateg01]

BTW! NO Grease of any kind or sticky products because they attract dust and dirt.

What does it matter if there's dirt on the terminal as long as the contact is maintained and corrosion is kept at bay?

 

[Chuckster in NJ]

What does it matter if there's dirt on the terminal as long as the contact is maintained and corrosion is kept at bay?

I agree with you about keeping corrosion at bay but when you start accumulating dirt on a battery terminal it will hold onto moisture and spread onto the battery case on hot summer days. There are so many battery terminal protection products available that will not attract dirt so why use grease………. I like to keep my engine bay clean and a dirty/greasy battery terminal detracts from a clean and well maintained engine bay.

 

[Stuart in MN]

I've put a light coating of whatever grease I had handy on the mating surfaces of the terminal and the clamp with good results, and since those surfaces aren't exposed they don't attract dirt. You don't have to smear it all over, the idea is to prevent corrosion in between the two. However, I think the red and green felt washers are a better solution.

If a person was conscientious, disconnecting, cleaning and reconnecting the terminals would be a good part of regular maintenance.

 

[four.cycle]

Neither.

Clear Krylon.

(Or ANY other product that prevents AIR from coming in contact with the terminal.)

Yes, bacon grease would work. Or lipstick. Or paint. Or fingernail polish. Or red permatex. Your choice.

 

[xjfish]

I use the NAPA aerosol products aforementioned at work. At home I typically do use a light coat of whatever grease is handy post assembly. I have used spray paint previously with good results. Mechanical cleaning first is typically best!

 

[bctexas]

The permanent solution to this problem is using a AGM battery. They do not corrode terminals or the car body surrounding the battery. For example, we bought a new Subaru in 1997 and shortly after we got it, I replaced the battery with an AGM and only used AGM batteries going forward. 20 years and 245,000 miles later when we sold it, it still had the factory battery terminals and hold down hardware in pristine condition, and there was zero rust under or around the battery. And this is without rings under the terminals, grease on the posts or any other preventitive measures. There are other advantages too but that is outside the scope of this thread. The downside is that they are more expensive, but I think the advantages justify the cost.

Happy Motoring!

 

[rlitman]

Old school. Big gob of Vaseline AFTER you install the battery terminal clamp.

Here is why. The "white crusty" stuff that you get around the posts and on the clamps is from gases leaking from inside the battery around the posts. A good "gob" of grease/Vaseline prevents the gases from escaping !

Those fancy felt washers that you put under the clamps do the same thing !

That's the right old-school answer, and there's nothing wrong with any of this (I do the same myself). But on sealed non-serviceable batteries, there SHOULDN'T be a need for any of this, because battery gases shouldn't be escaping. In theory, the posts get epoxied to the case, and maintaining a pressure tight seal is critical for battery life (once acidic gases escape, the battery starts to rapidly sulfate).

To that end, the best advice I can add is to never use one of those stupid battery carriers that lift the battery by the posts, and be gentle on the posts. If you have screw terminal posts, carefully follow the torque guidelines, because over-torquing the posts or moving the battery by the posts can break the epoxy seal (epoxy does not bond well to polypropylene battery cases).

And feel free to slather on the grease. If the acidic gases do escape, they'll protect your wiring. I like Fluid Film, and I also treat the threads on the J hooks to be kind to future me.

 

[theoldwizard1]

But on sealed non-serviceable batteries, there SHOULDN'T be a need for any of this, because battery gases shouldn't be escaping. In theory, the posts get epoxied to the case, and maintaining a pressure tight seal is critical for battery life...

I agre with you but ... they do seem to leak after a several years !

 

[rlitman]

I agre with you but ... they do seem to leak after a several years !

Yeah, it's a problem for sure. Remember that even if you protect the battery wires from corrosion (since they're the most exposed, they show the signs of corrosion first and take the brunt of the damage), acidic gases under your hood are no joke. If the battery is venting, it's time to replace it. Battery fumes are known to damage ground wires, your electrical harness and even head gaskets. All of those get expensive fast.

I tend to spray my batteries down with an indicating battery cleaner at least once a year, and if I'm seeing lots of acid, I know that battery's going to be replaced within the year.

 

[nadogail]

70 years ago, I was show #3 Permatex works well.