Battery corrosion

[Drew99GT]

Critic's battery post made me think: I have about a 4 year old Autolite Titanium battery in my car (Johnson Controls made), and there's a lot of moisture buildup on the top of the battery, and I'm starting to get the white corrosion on the hold down clamp. Non on the terminals or cables thankfully as I use the felt pads, which work great.

My question: is this a sign the battery is on it's way out? I did top off the cells with distilled water this summer. Car seems to crank slower when it's really cold out.

 

[StevieC]

I have seen batteries covered in white corrosion that were fine at the 10 year mark and others that were squeaky clean and gone at 3 years... Can't use this as an indicator. I would clean it up, and the battery connections though.

 

[SZR48207]

What car? Heat is a better determinant of battery life (quality issues aside), so if the engine compartment is cramped or if you live in Florida or Arizona, expect the battery life to be lessened.

I'd check the voltage with a hydrometer and then see if a battery place can do a load test on it.

 

[Drew99GT]

Toyota Corolla in Colorado, so not very hot. Plus, the way the engine compartment is set up, the battery get pretty good airflow when moving.

 

[Propflux01]

But question is, why does this stuff form on the teminals anyhow? I keep mine clean, tight and tidy, yet every oil change, there it is, on the positive teminal...

 

[Ben99GT]

I've been putting a dab of dielectric grease on my battery terminals for the last 1.5 years or so, it seems to totally prevent battery corrosion.

 

[brianl703]

Originally Posted By: Tim H.
But question is, why does this stuff form on the teminals anyhow? I keep mine clean, tight and tidy, yet every oil change, there it is, on the positive teminal...


It's because the seal between the battery case and the terminal is broken.

I'm not sure of the cause. Putting too much force on the battery terminals when tightening the terminal bolts might cause it. After the bolt is tight, all that extra force goes into bending the terminal post sideways, which could break the seal.

 

[SZR48207]

Originally Posted By: brianl703
Originally Posted By: Tim H.
But question is, why does this stuff form on the teminals anyhow? I keep mine clean, tight and tidy, yet every oil change, there it is, on the positive teminal...


It's because the seal between the battery case and the terminal is broken.

I'm not sure of the cause. Putting too much force on the battery terminals when tightening the terminal bolts might cause it. After the bolt is tight, all that extra force goes into bending the terminal post sideways, which could break the seal.




I thought corrosion is just a result of the battery venting hydrogen gas when it processes a current. The OEM ford battery in my vehicle did not cause much corrosion, but now my JC battery causes the positive clamp to corrode after a few thousand miles.

 

[StevieC]

I have never had corrosion on the tops of my battery when the terminals were coated in some sort of lubricant or di-electric grease. Also my car is rust sprayed every year and the over spray coats the battery so maybe that's why too.

 

[brianl703]

Originally Posted By: Reddy45

I thought corrosion is just a result of the battery venting hydrogen gas when it processes a current. The OEM ford battery in my vehicle did not cause much corrosion, but now my JC battery causes the positive clamp to corrode after a few thousand miles.


Hydrogen gas does not cause corrosion. Acid causes corrosion.

The vent caps on Johnson Controls batteries are designed to prevent acid mist from passing through. They have baffles inside. I found a patent number on the bottom of one of them and looked it up. When a battery produces hydrogen gas, the bubble produces a mist of acid when it reaches the surface and pops.

Neither of the deep cycle batteries I have connected to my APC UPS have any corrosion on the terminals, despite the fact that I have to add water to them more often than any car battery (meaning they are producing more hydrogen gas).

If the seal between the battery post and case is broken, acid will leak out and get on the terminal.

I've seen batteries where tightening the battery terminals made the post move. If you can see the post moving as your tightening the bolt..the seal is broken.

 

[mechtech2]

Wetness is not a good sign.
When you dry it off, it should be evident next time as to where it is emanating from.

 

[Drew99GT]

It's coming from the vent caps.

 

[brianl703]

Are the cells overfilled with water?

 

[Donald]

I had the negative terminal on the 7 or 8 year old battery in my Jeep keep getting covered in white corrosion powder. I poured a baking soda/water mixture over it a few times, but it would come back. Cells were not overfilled.

 

[Drew99GT]

Originally Posted By: brianl703
Are the cells overfilled with water?


No, they level is fine.

I'd like to get a maintenance free sealed batter next time, like AC Delco sells.

 

[brianl703]

AC Delco doesn't sell those anymore.

I think your only option might be Exide (some of theirs are "sealed" or East Penn (Deka).

Even the "sealed" batteries really aren't, they have vents.

You could get a European reverse-terminal group 47 or 48 battery with the vent tube connection, if you can fit one in.

I had one of the deep-cycle marine batteries I bought for my UPS fall over while I was taking it home. Nothing leaked out of it.

 

[paulo57509]

The battery in my Legend is at least 8 years old (was in there when I got the car) and the terminals are clean, but the hold down and the long bolts are covered with layers of white stuff and has been like this for the past few years. No electrical problems, but as soon as the new hold down parts come in, I'm replacing it.

I was told by the manufacturer of my battery maintainer through a Q&A e-mail in resonse to a similar fluffy appearance of corrosion on a motorcycle battery, that this corrosion is because battery is sulfated and is pretty much at the end of it's life. Shortly thereafter, this battery stopped taking and holding a charge.

 

[Drew99GT]

Brian, I checked and AC Delco now sells a battery that has deeper reservoirs that allow more electrolyte on top f the plates and claim that makes it maintenance free. But it indeed now has removable vent caps.

I should just take the darn thing in and get it tested - end the speculation!