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Technical Battery terminal grease

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Technical Battery terminal grease

oldmanhouse

oldmanhouse

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I'm swapping the battery in my GP later today, and following the write-up in the guides section.

One thing I'm not clear on is where you put the grease/petroleum jelly? Do you put a layer on the battery terminals and then attach the clamps so the grease sits between terminal & clamp? Or do you put it on the outside/exterior of the clamps?
 
DGPunto said:
Easy answer - both. Stope the terminals corroding

Personally I use petroleum jelly
Click to expand...

I wouldn't go that fast !

Connection should be metal to metal after good cleaning, THEN apply generously oil jelly or vaseline (which is neutral: no acid nor base) to insulate the terminal and clamp from acid vapours that cause the lead sulfatation...

BRs, Bernie

If someone here helped You fix -or better- understand your issue, hit the thanks button @ bottom right corner, it's free and makes us feel helpy ;-)
 
Thanks both, I have fitted the battery today

The only issue is that the positive terminal clamp is loose. If you pull it up, it comes right off. I have fully tightened the nut with a ratchet. Strangely, the negative clamp is very secure.

This is the battery I got. I was pretty sure it was the right one for my car (GP 1.4 16v 2008) when I bought it: http://www.exide.info/spec/eb500.html
 
Last edited:
Bernievarian said:
I wouldn't go that fast !

Connection should be metal to metal after good cleaning, THEN apply generously oil jelly or vaseline (which is neutral: no acid nor base) to insulate the terminal and clamp from acid vapours that cause the lead sulfatation...

BRs, Bernie

If someone here helped You fix -or better- understand your issue, hit the thanks button @ bottom right corner, it's free and makes us feel helpy ;-)
Click to expand...

Sorry Bernie, I have to disagree with you on this one. A thin layer of petroeum jelly (Vaselene) on the post and clamp before tighting the clamp is good practice. it does not stop metal to metal contact and ensures there is no air space between post and clamp. You would have to put a huge blob of jelly on the outside of the clamp to seal it fully.
Don't use Silicone grease, it can react with fumes or arcing to form a hard insulating layer.

Robert G8RPI.
 
oldmanhouse said:
Thanks both, I have fitted the battery today

The only issue is that the positive terminal clamp is loose. If you pull it up, it comes right off. I have fully tightened the nut with a ratchet. Strangely, the negative clamp is very secure.

This is the battery I got. I was pretty sure it was the right one for my car (GP 1.4 16v 2008) when I bought it: http://www.exide.info/spec/eb500.html
Click to expand...

Clamp should be tight. Can you post a picture of it?
It may have been overtightned in the past and damaged or it could be cracked.
Also make sure the clamp bolt is loose before pushing the clamp on to the post. It shold start to grip the post before you tighten the clamp (apart from quick release types).
If it was the negative that was loose I say maybe someone fitted a positive clamp (they are 1.6mm bigger)

Robert G8RPI.
 
g8rpi said:
Clamp should be tight. Can you post a picture of it?
It may have been overtightned in the past and damaged or it could be cracked.
Also make sure the clamp bolt is loose before pushing the clamp on to the post. It shold start to grip the post before you tighten the clamp (apart from quick release types).
If it was the negative that was loose I say maybe someone fitted a positive clamp (they are 1.6mm bigger)

Robert G8RPI.
Click to expand...


Possibly the post on the new battery is slightly smaller.
 
oldmanhouse said:
Thanks both, I have fitted the battery today

The only issue is that the positive terminal clamp is loose. If you pull it up, it comes right off. I have fully tightened the nut with a ratchet. Strangely, the negative clamp is very secure.

This is the battery I got. I was pretty sure it was the right one for my car (GP 1.4 16v 2008) when I bought it: http://www.exide.info/spec/eb500.html
Click to expand...

got a photo..??

in my experience the old-style LEAD clamps stay pinched,
I slacken off the nut and "gently with a socket / tube" tap the lead collar down over the battery post.. it's TAPERED so will spread a little on it's journey..;)

IDEA - I've recently bought a couple of battery isolators from ebay.. they are a poor fit ( hole too big).. I have sliced off a piece of copper tubing ( water pipe) to use as a sleeve - with a slit along it's length - between the 2..seems to work well as "conductive packing"
 
Last edited:
g8rpi said:
Sorry Bernie, I have to disagree with you on this one. A thin layer of petroeum jelly (Vaselene) on the post and clamp before tighting the clamp is good practice. it does not stop metal to metal contact and ensures there is no air space between post and clamp. You would have to put a huge blob of jelly on the outside of the clamp to seal it fully.
Don't use Silicone grease, it can react with fumes or arcing to form a hard insulating layer.

Robert G8RPI.
Click to expand...

Hi Robert and All,

one continuously try to get the best as possible electrical connections on our cars, mainly because of the low voltage the amps are quite high and the smallest lost in a resisting point can (and will) create trouble.
So why on earth would one put insulating jelly (unless vaseline is better conductive than copper ?) at the very source of the power ??

Lead sulfatation is actually an indicator of something going wrong !! Either someone spilled electrolyth and didn't clean the battery cover, or the battery is over-charing (bad voltage regulation) and exhausts massive gases thru its vents...
So that white/blue-ish powder should NOT be there in normal condition.

Maybe you put jelly on the post and it works, fine with me, but personnaly I've always clamped the connector DRY and put the vaseline on top. 45 years driving and taking care of my cars and my battery posts are still clean as new...

Best Regards, Bernie



If someone here helped You fix -or better- understand your issue, hit the thanks icon @ bottom right corner, it's free and makes us feel helpy ;-)
 
Bernievarian said:
Hi Robert and All,

one continuously try to get the best as possible electrical connections on our cars, mainly because of the low voltage the amps are quite high and the smallest lost in a resisting point can (and will) create trouble.
So why on earth would one put insulating jelly (unless vaseline is better conductive than copper ?) at the very source of the power ??

Lead sulfatation is actually an indicator of something going wrong !! Either someone spilled electrolyth and didn't clean the battery cover, or the battery is over-charing (bad voltage regulation) and exhausts massive gases thru its vents...
So that white/blue-ish powder should NOT be there in normal condition.

Maybe you put jelly on the post and it works, fine with me, but personnaly I've always clamped the connector DRY and put the vaseline on top. 45 years driving and taking care of my cars and my battery posts are still clean as new...

Best Regards, Bernie



If someone here helped You fix -or better- understand your issue, hit the thanks icon @ bottom right corner, it's free and makes us feel helpy ;-)
Click to expand...

Hi Bernie,
No, PJ is not more conductive than copper (the posts are lead and clamps plated brass or steel), but it's not making the conductive path. At a microscopic level both the post and clamp surfaces are rough. It the points of the roughness that make contact and they displace the PJ. The PJ fills the valleys and imperfections forming a gas tight seal. Remember we are talking about a thin layer, just a wipe of PJ. It also helps lubricate the joint during assembly allowing a higher contact pressure. This is standard practice on aircraft batteries and a bad contact is a bigger problem when flying, you can't pull over and call the breakdown service. Quote from Concord battery handbook http://www.batteryshop.com/manuals/nicadmanual.pdf
" E. Coat cell terminals and connector links lightly with neutral, non-acid, petroleum jelly, using a small brush".
( I'm a licenced aircraft engineer).
 PJ filled connectors are also standard on telephone systems Google jelly crimp.
Exterior application is better than nothing but a thin layer on the post before clamping is best practice.


Robert G8RPI.
 
Hi Robert, will follow your advice next time, shouldn't hurt as you describbed it a microscopic level ;-)

Cheers, Bernie
 
Just to come back with an update on my positive clamp issue (was very loose). One time my car started OK but the battery light came on and PAS died, so I decided to take some action as I thought it was probably related to my positive clamp.

I just tapped the ring down a bit gently with a small hammer and it now sits much more snug. The terminal gets wider toward the bottom, so it just needed to go down a bit more. No more battery light so far... alternator was supposedly OK when I first got the car checked, so hoping this holds true!

Thanks all for your useful contributions, great to have so many knowledgable members on the site :)
 
Hi All,

both terminal and clamp are conical, the right way to connect them is to lose the clamp, install on terminal and force it down (gently) and then tight the clamp. Of course the parts need to be clean of any oxydation and debris: the more surface in contact, the better the connexion, with less resistive loss...
And remember always disconnect ground first and reconnect last !

BRs, Bernie

If someone here helped You fix -or better- understand your issue, hit the thanks icon @ bottom right corner, it's free and makes us feel helpy ;-)
 
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