Battery posts / terminal and Vaseline.....

redgtxdi

Diamond Member
Jun 23, 2004
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So I had a Duralast Gold replaced yesterday (just outside of the 3yr free replacment warranty, of course). The guy helping was installing the new battery and wasn't happy about finding vaseline between the connector and the post itself. I looked at him a little crazy as I've used Vaseline for *about* 20 years. Those green/red felt things suck. Any other tricks suck. I always end up having to use some baking soda & water to clean terminals/connectors when I install new batteries and Vaseline has always worked wonders for me.

He went so far as to say that the Vaseline (I didn't tell him Vaseline, I let him believe Auto Zone installed the battery & probably used some terminal grease) being between the connector and the post is what probably killed the battery.

I'm a car guy so this would surprise me but maybe I'm wrong on this one.
 

Murdoc

Member
Jan 22, 2011
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I use dielectric grease. I doubt the vaseline killed the battery, as long as the wire terminals were on good and tight.
 

jagec

Lifer
Apr 30, 2004
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I would LOVE to hear his reasoning on how vaseline on the terminals (or any other grease, for that matter) would kill a battery.
 

redgtxdi

Diamond Member
Jun 23, 2004
5,464
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After further searching, I did find this thread.......

http://www.ybw.com/forums/showthread.php?t=227473

I only read page 1 but looks like there is some consensus that clean contact followed by Vaseline (or dilectric grease) *AFTER* or *OUTSIDE* of that metal to metal connection was taught as gospel at some point.

I, too, however would be curious as to why. What could possibly be in petroleum jelly that is ok to dress as a covering for the connection, but could possibly harm or degredate the battery as a result of terminal/connector contact???

:confuzzled:
 

WilliamM2

Platinum Member
Jun 14, 2012
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I always clean the terminals and connectors, and then apply whatever is handy. Vaseline, wheel bearing grease, dialectric grease, whatever. A thin coating is all that's needed, and I've never had any issues.

I've also used the green felt pads after Autozone insisted, terminals turned white in less than a month, so I cleaned it up and did it my way. I'm not even sure what the theory is on why the felt pads would stop corrosion.
 

jagec

Lifer
Apr 30, 2004
24,442
6
81
After further searching, I did find this thread.......

http://www.ybw.com/forums/showthread.php?t=227473

I only read page 1 but looks like there is some consensus that clean contact followed by Vaseline (or dilectric grease) *AFTER* or *OUTSIDE* of that metal to metal connection was taught as gospel at some point.

I, too, however would be curious as to why. What could possibly be in petroleum jelly that is ok to dress as a covering for the connection, but could possibly harm or degredate the battery as a result of terminal/connector contact???

:confuzzled:

It's more to make sure that you are making a good metal-to-metal electrical connection before you add the grease. In theory adding the grease first and then tightening will squeeze enough of it out that your connection will be OK, but given that it's just as easy to add it afterwards, why take the risk?
 

franksta

Golden Member
Jun 6, 2001
1,967
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I always clean the terminals and connectors, and then apply whatever is handy. Vaseline, wheel bearing grease, dialectric grease, whatever. A thin coating is all that's needed, and I've never had any issues.

I've also used the green felt pads after Autozone insisted, terminals turned white in less than a month, so I cleaned it up and did it my way. I'm not even sure what the theory is on why the felt pads would stop corrosion.

I always thought the little felt rings were for quick identification of positive vs negative terminal. Are they sold as a corrosion inhibitor?
 

Throckmorton

Lifer
Aug 23, 2007
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Vaseline is an insulator. You aren't supposed to put it BETWEEN the connector and the post. You coat the whole thing to block out oxygen. What made you think insulating the battery from the wire was a good thing? That's the whole reason you don't want corrosion, because it causes connection problems.
 
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phucheneh

Diamond Member
Jun 30, 2012
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Vaseline is an insulator. You aren't supposed to put it BETWEEN the connector and the post. You coat the whole thing to block out oxygen. What made you think insulating the battery from the wire was a good thing? That's the whole reason you don't want corrosion, because it causes connection problems.

While I agree that terminals and posts should be bare and clean when fitted together (apply your choice of sealer after they're tight), I don't think you get the idea of dielectric grease. I'm not sure how similar it is to vaseline...the latter is petroleum based; dielectric is a silicone grease with similar consistency.

Dielectric grease is generally unconductive. I would assume vaseline is, too. Yet you can stuff gobs of it into electric connectors, plug them in and actually fix problems with the stuff. The obvious example being spark plug boots- it's not just to make them easier to pull off (actually makes the boot more prone to sliding while the metal stays on the plug). It's to seal out moisture and to block the high voltage from finding a ground that's not on the other side of the spark plug gap.

It works because these connections rely of pieces of metal fitted in tight contact together. The grease is able to be pushed out of the way by the metal contacts, ultimately not reducing the quality of the connection- the space inside that's filled by goo would have just been filled by air (...not a good conductor) anyhow.
 

Howard

Lifer
Oct 14, 1999
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Vaseline is an insulator. You aren't supposed to put it BETWEEN the connector and the post. You coat the whole thing to block out oxygen. What made you think insulating the battery from the wire was a good thing? That's the whole reason you don't want corrosion, because it causes connection problems.
I am curious about something - do you believe that Faston connectors would not work well if they were liberally coated in vaseline before connection-make?
 

bruceb

Diamond Member
Aug 20, 2004
8,874
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On a top post battery, you should use the special felt washers. They do help. Also be sure to clean the inside of the cable terminals and the post with a special scraper to insure a good clean, connection. Tighten properly (do not overdo it) and then lightly coat the top of terminal with grease. This will keep corrosion to a minimum.
 

redgtxdi

Diamond Member
Jun 23, 2004
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I am curious about something - do you believe that Faston connectors would not work well if they were liberally coated in vaseline before connection-make?

If it wasn't obvious.......Howard's setting up a "curb stomp". ;)

Like saying, "Ok, coat your finger in vaseline & then stick it in the 110 outlet. You'll be fine. Vaseline is an insulator" :lol:

I just kind of wondered what consensus was. I can't imagine that metal to metal contact would not have been made sufficiently (ever notice it's usually rarely "kinda" connected?) with or without Vaseline or any other grease.

What's really funny is that the little packs of grease at the auto store all say "apply liberally" and don't make mention of post/before/after/between/etc. I would think it's good. Vaseline has literally kicked hard-@$$ against anything else I've ever used.

Felt rings ---- (yes, they truly do SUCK and do virtually NOTHING. 20 years & 6 cars later, I can concur)

Silicone Grease ---- (good, but to be honest, still not as good as Vaseline, imho)

And I can't count the number of terminals I've cleaned with baking soda & water. Amazing chemistry experiment in action. My truck will be getting a dose soon.

;)
 

Throckmorton

Lifer
Aug 23, 2007
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I am curious about something - do you believe that Faston connectors would not work well if they were liberally coated in vaseline before connection-make?

Do you believe that corroded connectors would not work well? Obviously metal can contact metal there will be a connection, but it's not going to be as good as a connection without grease...
 

phucheneh

Diamond Member
Jun 30, 2012
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There are good felt rings, they come wetted down in something that I don't touch without gloves. Some kind grease that feels a lot like diesel. Mineral oil, maybe?

Anyway, whatever's on them is what makes them work. The cheap dry ones just absorb a little acid, but don't provide a lasting barrier.

Either way, even with the good pads, you need to change them out periodically. And they're probably as expensive as a whole can of generic 'battery insulator.' The stuff that's close to red paint works fine- it serves the same purpose as the thick grease barrier, just less messy. Arguably not quite as effective as if the terminal is kept coated in a liberal amount of grease...but it sucks dealing with that mess when you need to replace the battery or otherwise disconnect the terminals.

Literal paint will also work. As will a glob of suspension/wheel bearing grease. Anything that forms a barrier around the exposed post and terminal.

edit: grease is different from corrosion. Corrosion isn't scraped and/or squeezed out of the way when a connection is made. As long as you don't pack the connector so much as to put pressure on parts inside it (i.e. forcing weatherproof connectors with too much grease together), dielectric grease isn't going to add resistance to a 12v automotive circuit.
 
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Raizinman

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Sep 7, 2007
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The corrosion in part comes from the electrical leakage across the top of the battery. It's important to keep the top of your battery clean and dry. A tip from an old mechanic is to glue a penny to the top of your battery. When the electrical current starts to go from one post to the other, it will stop at the penny and the penny will take on the corrosion. Yes, you might need to replace the penny after a few years. Just glue the penny somewhere between the POS and NEG posts.
 

Throckmorton

Lifer
Aug 23, 2007
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The corrosion in part comes from the electrical leakage across the top of the battery. It's important to keep the top of your battery clean and dry. A tip from an old mechanic is to glue a penny to the top of your battery. When the electrical current starts to go from one post to the other, it will stop at the penny and the penny will take on the corrosion. Yes, you might need to replace the penny after a few years. Just glue the penny somewhere between the POS and NEG posts.

Sounds like BS... I don't think any electrons are making their way across the plastic top of the battery, and even then the penny would just help them along on their journey.


The simple solution is to get a sealed battery like an Odyssey or Optima and never worry about your battery until it dies in 5 years.
 

phucheneh

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Jun 30, 2012
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Yes, electrons can and do make their way across the surface of the casing. But I don't think copper-coated zinc is going to serve the purpose of a sacrificial anode.
 

Howard

Lifer
Oct 14, 1999
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Do you believe that corroded connectors would not work well? Obviously metal can contact metal there will be a connection, but it's not going to be as good as a connection without grease...
I believe that corroded connectors are a waste of energy, but whether they work well enough is dependent on the application and the type of connector.

A dry connection "obviously" being better is just the immediate observation, true only for some cases. A Faston connection is designed to scrape away corrosion so you damn well better believe I think grease isn't going to matter at all for a connection like that.

EDIT: Wait, are we arguing or agreeing?
 
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SilthDraeth

Platinum Member
Oct 28, 2003
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My dad used to use maple syrup if handy. However, maple syrup is expensive and I would rather be eating it than putting it on a battery terminal.
 

Raizinman

Platinum Member
Sep 7, 2007
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meettomy.site
Sounds like BS... I don't think any electrons are making their way across the plastic top of the battery, and even then the penny would just help them along on their journey.

The simple solution is to get a sealed battery like an Odyssey or Optima and never worry about your battery until it dies in 5 years.


Sounds like BS? Yes, I'm sure the world being round also sounded like BS a few hundred years ago too. When the electrons move across the top of the battery, they attach themselves to the penny and the corrosion happens to the penny, not the terminals. A penny is much cheaper than purchasing an Odyssey or Optima battery. Last I checked an Optima Yellow was around $240. I paid $75 for a 6 year, 36 month free replacement battery at Costco. Well, make the true cost $75.01 less tax.