Long-term OEM Battery owners - any corrosion?

my neg did once, cleaned with baking soda and water, took some of the silver paint? off the end, shows the copper now but never enough to cause a connection prob, must be the batt venting acid vapors, positive has the cover and never affected......needs a cover on the neg possibly

 

I went with an Odyssey AGM and diddn't look back.

 

Sorry... But that does not happen unless the battery is tipped over on its side or the case is squeezed/deformed (or the battery being seriously overcharged, such as from a bad alternator whose VR has full-fielded it). The vents have baffles inside them that prevents the acid from simply sloshing out.

Excepting for a crack in the case, this almost universally is from acid seepage that comes from under the caps (their seals are just hard plastic plugs pushed against the hard plastic case, there are no rubber o-rings or the like). I've had good success stopping it by wrapping the cap plugs with teflon plumbers tape then pushing them back down onto the battery (acid doesn't affect the teflon). Just make sure the tape isn't blocking the vent holes on the inside of the cap.

 

Inform me

What design feature of an absorbed glass mat battery provides immunity from terminal corrosion?

Wishful thinking is the only detail I can see.

 

Batteries need to breathe.

It can not be stopped. Call it a Chem-Mystery Hydrogen evolution and all that.

Acid vapor is real!

 

Mine leaked within the first year. It spilled forward down the inner fender behind the headlight, and also took off the coating on the battery hold down bracket. I went to a sealed battery after that.

 

Acid that gets on the top of the battery case is what causes corrosion of the terminals and other metal parts it comes in contact with.
AGM batteries generally do not leak acid because (1), they don't have these plastic caps with mediocre plastic-against-plastic seals on their cases (the cases are hermetically sealed and the vents have valves that will only open under pressure), (2), the acid is contained in glass-fiber sponges so it is not sloshing around.

That same battery over a year later:


It's been bounced around on at least a dozen offroading trips. No terminal grease, no terminal (felt) washers, no sign of acid exiting the vents (or from under them), no corrosion.

Again, the vents have internal baffles that prevent splashed acid/acid vapors coming through (I think they call it 'recombinent' IIRC, which returns the vapor as acid back into the cell).