Weird Battery Post Oxide/Corrosion Build-Up… help!
 

Hey. I have my 325 watt subwoofer amp hooked up to the positive terminal of my battery by way of a 4 gauge wire with a copper or brass connector at the end, which I bolted onto the battery post where all the other wires connect.

After about 5 months now, though, I opened up by battery compartment, and to my surprise, found this:

https://www.rx8club.com/attachment.p...chmentid=97248

https://www.rx8club.com/attachment.p...chmentid=97249

There is a hugeee amount of blue build-up on the battery post. Though it could be unrelated, it seems as though this is caused for some reason by my subwoofer power-cable connection. The “oxide” build-up or whatever it possibly could be, is kind of crystal like, very dry and crumbly. You can see some of the build-up that has crumbled off when I lightly touched it with my fingers.

Does anyone know what this is or what has caused it? I’ve never seen or heard of this before…

I would assume the stuff is solidified battery acid. Or at least it probably has an acid component. Be careful getting rid of it. Baking soda and a little water will neutralize it so that you can get it off.

Remember, acid will eat just about anything it comes in contact with. It can seriously burn skin and eyes, so be careful. Wear the rubber gloves, old clothes and eye protection when messing with this stuff. Might be better to carefully remove the battery from the car to clean it.

could be... and thanks for the warning.

but more important is why... why is this happening to my battery? should i be worried? someone???

It looks like something is leaking, like Go48 said clean it carefully.

They sell some grease thing at autoparts store to prevent this from happening, its freaking cheap like 99 cents, buy it, clean it, sandpaper it, apply it. and be happy with it.

After you clean all connections to both battery posts and make sure they are tight, apply a little Vaseline to the connections/battery posts. The cause of your problem could be venting from an overcharging battery. Or it could have something to do with that funky cable connection you have to the positive post. Check the alternator output to see if it is within spec. At least check the battery posts again in a month of so to see if the material continues to build up.

Those pretty, blue crystals look like Copper Sulfate :). Is there a copper connector under all that?

Anyway, took a good bit of battery acid to do that. I don't think the cable itself is a problem, but in the process of tightening it down you might have placed a strain on the battery post and got a leak where it seals to the case. Other possibilities are that someone overfilled the battery with water when topping off, loose cap, overcharging, cracked case, etc...

Judging from the amount of accumulation, once you get it all cleaned up, it shouldn't take long to discover where the acid is coming from.

Consider getting an AGM battery, like Optima. No leaks! :)

yeah, thats exactly what i was thinking but i had no idea why acid would be leaking from my battery... after all, copper, iron, AND nickel sulfates all form blue-ish green-ish crystals.

and i just remembered that i had to apply a ridiculous amount of pressure to loosen the factory bolt that i used for my positive amp wire connection, and probably twisted or pulled the entire positive battery post in the process...

thanks for the tips everyone!

All non-sealed lead-acid batteries leak acid. Its not liquid when it leakes, its vapors outgassed by charging the battery. Hydrogen, and Sulphuric acid. Those get attracted to the terminal because they are ionized, and form salts (the solid form of the acid). You either have to vent the gasses to the outside with a hose, use a sealed battery, or clean the terminal and coat it with something to keep the vapor away, like dielectric grease or vaseline.


Your problem may be that you are using dissimilar metals to join the connection. This causes a little local battery which makes for corrosion city. Compound that with the gasses that vent out of your battery when it charges and you get a metal salt mess.

I would replace the connections. Then coat with vaseline or dielectric grease. If that doesn't work, either use differant metals to connect to the terminal post or replace the battery with a sealed type, like an optima.

Well said Corners!

hey... so i brought my car to the dealership to have the problem looked at, in hopes that they would get me a new battery...

instead, they called me with a quote and told me that the wiring harness was damaged and is causing the problem... AND that it costs 2900 dollars to replace the wiring harness!! 2900?!?

i realize the terminal is corroded, but is it really possible that the "wiring harness" is causing the problem, and that it's not just a leaky battery?? seems like i can replace my damaged wiring harness, and yet my battery will still leak onto the new harness...

and 2900 dollars? what IS the wiring harness? that little metal thing that is corroded in my pictures? no way is that 2900 dollars...

help!!!

Harness, schmarness!

Get yourself an Optima battery. Here's a picture of the one I installed in April 2005. The connectors are pristine to this day! Clean or replace your corroded connector and replace the battery with an Optima. The Yellow-top has good deep-discharge tolerance, which may be a plus with that stereo of yours :)

By the way, you might want to put a little extra protection/isolation between that fat wire and the tower brace. If that were to rub through you'd have a direct path to ground, capable of a whole lot of current, and fireworks.

https://www.rx8club.com/attachment.p...0&d=1112774651

Check the DIY section.

Optima batteries weigh a ton, well not that much but they're heavy ....

+1

The only bad thing about Optima battery is their weight. they are heavy as HELL. I got one for my brother's altima ser, cuz he was a moron and drain his battery couple of times and its not taking charge anymore(yeah, left the radio on for hours ) the optima battery cost I think 189.99 at pepboys. it really rock.

Im planning to get one for myself too, but Im just gonna wait till the Mazda battery dies .... no point of wasting money right now.

alright, sounds good... i definitely don't think i need a new wiring harness, because the battery is the issue, not the wiring harness...

buttt i do need a new metal connector... the acid has eaten almost entirely through my positive terminal connector thing... should i ask the dealership to get me JUST that part and give it to me or install it for me? or can i buy a "positive battery terminal" from like circuit city and use that?? is that possible? the only issue then would be that the original wiring has that built in 120-amp (i think) fuse right there... what would i do about that??

any suggestions are muchh appreciated!

You can get one of those positive terminal connector at your local parts store for a few bucks each. But you have to cut and slice the wires yourself. Its not that hard.

what about the 120-amp fuse though? or whatever that is...

if u dont have baking soda n water available to clean the battery terminals, get urself some room temperature coca cola soda....drip some on to the terminals with the battery off n itll eat up the corrosion...

My positive battery terminal does the same thing . I have removed it twice in a year and the same blue crystals come back. I cleaned it ,put dialectric grease on it and today it blew apart on startup. It was ate all the way through. I called my dealer and they said the new part was 49 dollars. What a rip off. It is a chincy little piece of copper I went to Advance Auto Parts and got the end connector part for $3.50. Part number A1501142.The little plastic cover wont fit over the supplied wingnut unless you cut the bolt off a little, or just get a shorter bolt. I don't have any amp wires or anything connected to my battery. This seems to be a common problem. Everybody better have a look at their battery . Oh yeah now my DSC is off light is flashing. what do I do now? Thanks

Well, I could say RTFM, but instead I'll tell you what to do. Turn the ignition key to the on position (don't start the car), turn the steering wheel clockwise all the way to lock and then all the way counter clockwise and back to center. Turn off the ignition and the light will be out when you turn the key back on.

cheap factory battery leaks in this area coupled with Mazda using aluminum terminal connectors results in the problem. It's mostly galvanic corrosion from the dissimilar metals accelerated by the sulphur acid gas.

there is a red spray available from most auto parts stores that you can spray it down with to minimize buildup after it has been cleaned. Put some baking soda on it and add some water, may several applications but it will knock that mess down and allow you to take it apart and brush it clean the rest of the way.

I had problems with the factory aluminum connectors and replaced them brass racing terminals having the wingnut holddown. It fit underneath the factory positive terminal cover without modification. They make disconnecting the battery much easier. I just pop the wingnut off the negative terminal and lift the cable loose. I don't have the problem anymore.

Thanks Go48.

They also sell the red and green felt washers that go under your battery connectors. They will prevent corrosion from forming. You can actually get them at Walmart for under a buck.

Get the Optima battery and a set of marine battery terminals at any auto parts store. All your wires hook to the post, no need to splice, and the black cover is tight but fits without cutting the bolt on the new terminal. However, you need to use the negative terminal from the marine set so the OEM wires fit - but the positive post is larger, so you need to open that clamp weider (is lead, so soft, take your time with a screwdriver and pliers).

Nice (or not so nice) to see I'm not the only one with a battery corrosion issue. I didn't take a before pic, but my battery was the same as 1145climber posted. To remove the corrosion:

1- Use a mix of baking soda and water (to make a paste... left mine a little watery) and let the paste sit on the terminals for 5-10 mins. Wear rubber gloves and goggles... it is highly corrosive battery acid after all! You will hear and see the paste react with the battery acid instantly.

2-After about 5-10 mins and no more sign of a reaction, hose off the battery!

Here's some pics of during and after... lools cleaner than off the shelf!

Oh, almost forgot... disconnect the negative terminal from the battery before ANY cleaning of the battery!! (Sorry if this was already mentioned).