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Battery Terminal Corrosion...


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1990 Legacy LS, Auto, AWD

 

Had to disconnect the battery about a week ago -swapped out the rear hatch & had to do some wiring work.

 

The Positive terminal had a bit of corrosion buildup on it - cleaned it up before hooking it back up.

 

less than a week later - had to jump start my moms car so we could move it - popped the hood, pulled back the pos. cover & the terminal is covered in corrosion again! (possibly even worse than it was before)

 

What causes this??? is my battery going bad?? alt?? connections are all tight...car starts easily...

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What works for me...

1) Thoroughly cleaning the top part of the battery. Electrolyte there can make an electrical path from one post to the other. Small but enough...

2) Buying felt doghnuts that slide on the posts and rest under the connector impeding electrical leaks acroos the posts.

3) Smearing the posts with spark plug boot grease.

YMMV.

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Well all wet-cell batterys leak acid once in a while (Just normal) and if you don't open your hood check/clean things on a ragular basis that does get built up and can also couse corrosion on a terminal. Is your battery maintenance free or can you pop off the covers? Check the levels and see if its running low, then you'll know that is whats causing your corrosion.

 

-Tom

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Thanks for the replies guys.

 

I was just amazed at the amount of crud build up in less than a week!

 

Pretty sure it is a maintenance free battery, but not sure of the age - was in the car when i got it & i've had it for 2 years now - might be time for a new one, regardless...

 

Will definitely do a voltage check on both the battery and the alternator - dont need either one failing on me with cold weather coming in. :-\

 

I do check things on a fairly regular basis and the corrosion buildup is something pretty recent (less than a month) :confused:

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Clean the battery with baking soda and water solution.

 

Check the Alt output, an overcharge can cause this.

 

Check to make sure the clamps are truly tight.

 

test the battery.

 

What amazed me about this method is how long it keeps the corrosion from re-forming, even after rinsing the area thoroughly.

 

 

 

Dave

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Just as a side note to the OP...You could always pop a penny or two or 3 under the battery hold down...Ive heard that the copper will attract corrosion instead of the battery posts...Ive seen it before and It has seemed to work...Just and Idea..:)

 

AKA "sacrificial anodes". I have not seen those pennies used for that since battery tops were real soft, almost like a thick tar that the pennies could easily be pushed into.

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Well, stopped at the parts store while I was in town today and had battery & alternator checked out - the good news is the alt. is still good - bad news, battery is on its way to failing - will be replaced asap - we have another, newer one on hand, just need to make sure it has a full charge before i put it in & get the terminals cleaned up good. :)

 

Thanks again for all the info guys!

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Well, stopped at the parts store while I was in town today and had battery & alternator checked out - the good news is the alt. is still good - bad news, battery is on its way to failing - will be replaced asap - we have another, newer one on hand, just need to make sure it has a full charge before i put it in & get the terminals cleaned up good. :)

 

Thanks again for all the info guys!

 

there are various products out there to reduce / prevent the corrosion. i use one by CRC i think, comes in a spray can like paint has a slight tint to it and works pretty good. i didn't really expect it to but it has.

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Yeah - I use the battery terminal spray as well after deactivating the acid in the area with baking soda and water. I try to wire brush any rust and throw down some semi-gloss black on the battery shelf to keep the rust at bay.

 

I never seem to have issues with corrosion and my batteries last nearly forever - only on cars that I've just bought or one's that come into the shop do I see this. Never on my own rigs. I always wipe the battery down when I'm working in the area to keep dirt and dust from shorting the terminals.

 

GD

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What amazed me about this method is how long it keeps the corrosion from re-forming, even after rinsing the area thoroughly.

 

 

 

Dave

 

Service free batteries are still vented, so you do get battery acid around the vents. This goo doesnt wash off, but mix and acid and a base, they neutralize and it easily becomes clean :).

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Yeah - I use the battery terminal spray as well after deactivating the acid in the area with baking soda and water. I try to wire brush any rust and throw down some semi-gloss black on the battery shelf to keep the rust at bay.

 

I never seem to have issues with corrosion and my batteries last nearly forever - only on cars that I've just bought or one's that come into the shop do I see this. Never on my own rigs. I always wipe the battery down when I'm working in the area to keep dirt and dust from shorting the terminals.

 

GD

 

is this spray readily available at the various parts outlets?? might have to grab a can of that.

 

and the battery is the one that was in the car when i got it, so no idea of its real age...

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Service free batteries are still vented, so you do get battery acid around the vents. This goo doesnt wash off, but mix and acid and a base, they neutralize and it easily becomes clean :).

 

It stays clean longer than you'd expect, is what I'm saying, even if you rinse all the baking soda off.

 

It's as though it takes a fair bit of buildup to start the corrosion process, and if you get rid of all the acid-y buildup, you won't get any corrosion for a while, without using any spray or goop.

 

 

Dave

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well, got the corrosion all cleaned up - was pretty nasty - very damp & turning blue - ended up taking the cable ends completely apart to get at it all - a pain, but worth it i think.

 

the 'new' battery is just over a year old - 10/08 - and has a full charge now - was down a little from sitting unused - hooked it up to the charger overnight and it should be golden now.

 

cable ends have a coating of dielectric grease, and will smear a little on the battery posts, too, before hooking it up.

 

and just to be sure, will take it in to have it checked/tested again...

 

when i had the old battery tested - supposed to be 580 CCA - tested out at only 467 CCA :eek: (ambient temp about 45 degrees F)

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Im having the same problems. I replaced my battery last year. Used some vasoline (recomended) on the terminals. And i have corosion this year. On the same note, the battery in my wifes van failed the same time last year

(-37). I bought a diehard from sears and got there instalation kit which included a brush to clean everything up, the red and green felt stuff to go undernieth the terminals and the spray. No corrosion for that one. I do however on my car have the corosion heading back into the cable so more then likelly i will need to hack some off or replace the whole thing.

 

Ben

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Im having the same problems. I replaced my battery last year. Used some vasoline (recomended) on the terminals. And i have corosion this year. On the same note, the battery in my wifes van failed the same time last year

(-37). I bought a diehard from sears and got there instalation kit which included a brush to clean everything up, the red and green felt stuff to go undernieth the terminals and the spray. No corrosion for that one. I do however on my car have the corosion heading back into the cable so more then likelly i will need to hack some off or replace the whole thing.

 

Ben

 

Dont go hacking your cables up - will pull the ones from Hildy & send them to you with the other stuff. Never had a corrosion problem with her. The Legacy is a little different...

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One of the Subaru repair shops out west claims this is a factor in the Ej25 head gasket failures, so I guess your head gasket is about to blow :lol::lol::-\

 

 

Its a little bit early to be hitting the ol eggnog. Maybe they have been sniffing the carb cleaner.

 

 

nipper

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