Off-Topic: Car Battery Corrosion on Battery Hold-Down Bracket

D107

Have a 6 year old fine-working Interstate MTP-35 battery in my 2012 Nissan Sentra. Just had it inspected and oil filter-lube etc. I looked at my battery afterwards and while I was easily able to clean off most of the corrosion powder from the negative side, the powder under the bracket concerns me as my guess is somewhere along the line a service attendant must have overtightened it possibly causing a leak--which I wouldn't want to mess with.
However I think the fact that the white powder appears on the right side of the bracket only--the same side as the powder was on the negative terminal could mean that the dust migrated by wind or vibration. If that's the case, it might be worth cleaning and see if it returns. Any thoughts?

STEVEusaPA

I’d take the bracket off, wire brush wipe down anything affected, put it back together, check it in a few weeks.

D107

Makes sense @STEVEusaPA except as with some rusted fixtures in the plumbing and HVAC fields, sometimes the corrosion is the only thing holding everything together, and looking at that bracket again I wonder if removing it will uncover a gaping leak that I won't be able to handle myself.

mattmia2

Electrolyte leaked out either around a terminal or a cap or someone splashed some while removing the caps to check the level. It isn't leaking because of damage but it is leaking a little, hose it off with some baking soda every once in a while.

I'd clean and paint where it is corroded.

Zman

I don't think I have had a car battery last much longer than 6 or 7 years. If I was going to take the time to pull it apart and clean it, I would just replace the battery.

I cracked battery is pretty rare unless it loses charge and freezes.

bburd

The best thing for that corrosion is a baking soda solution, but don’t get any of it inside the battery since it will neutralize the acid.

Jamie Hall

That's a maintenance free battery, so an acid spill wasn't from that battery. May have been there and going for quite some time. It's also trivial. If you don't care for the looks of it, take the bracket off, wire brush it clean as has been said, if you're really finicky get some black gloss RustOleum and spray it down. Clean up the threads on the J hook and lube them (don't drop the J hook -- easy to do and hare to undo!).

There won't be a leak under that, If were, you'd know it by now (dead battery).

mattmia2

That battery is not "maintenance free". If you grab and wiggle those vent caps they pull off and you can check/fill the electrolyte. It should be somewhere between the little post thing and the top of the slot. It looks like there is an oval of electrolyte that has seeped/sloshed out/been pushed out by evolving hydrogen and is on top of the battery.

Jamie Hall

Well, that is true. Maintenance light might be a better term. And does look as though -- on second look -- there had been a little leakage recently -- though I doubt that it is serious. Worth checking to see if the battery is being overcharged, though, if there is any leakage.

mattmia2

All "maintenance free" means is that they try to alter the chemistry a little so ti boils off a little less of the water and the give it more volume to hold more electrolyte. Ideally you would still remove the caps occasionally and check the level. "Maintenance free" usually has caps that screw in and are hidden under a label instead of that push on like the ones on this battery. Those caps are just little nylon stoppers with a vent in the top hooked together that push in like a cork in a bottle.

reggi

WHAT ↕️  @mattmia2 describes plus overfill runoff...
@Jamie Hall has those j hooks nailed... 

Don't forget to check the Battery Tray for damage and decay....

D107

Thanks all. I always find that hvac guys have a wide range of technical knowledge esp for vehicles--which most of you depend on for your service areas.

MaxMercy

Compared to some of my cars, that looks pretty benign actually. I'd just get a bucket of water and add some baking soda to it. Pour it on and use a paint brush to brush it clean, then rinse.

My Mazda is tough on batteries, but it runs about 14.5-14.7 charging voltage, so I suspect it out-gasses a bit. It always seems to have fuzz growing on it. I replaced the alt several years ago and that one runs on the high side as well. Supposedly, the PCM controls the regulator in this model.