Why is my battery terminal corroding?

[pet575]

I've done a Google search on this but I can't find the answer I'm looking for. I've got a new-ish (less than a year old) battery charger that can do a fast, trickle charge, or maintain. I use it for my two batteries on my boat and they were brand new last season. Everything charges just fine there with no issues.

I've previously used it for my riding lawnmower battery as well. Hooked it up to my riding lawnmower battery this winter and it started corroding the positive terminal on the battery and the positive alligator clip for the charger is now corroded and completely trashed. I understand all of the stuff about gases the battery gives off but this batter is charging in my garage on a wooden workbench with plenty of ventilation. The gases shouldn't be an issue in this case. I keep all of my battery terminals very clean and coated with dielectric grease.

So what the hell is causing this corrosion? Is the lawnmower battery going bad? WTH?!

[Okie Boarder]

I would suspect the battery. It is possible it isn't fully sealing and there is a wicking or leeching effect, I guess. If you leave it off the charger for a while, what happens?

[pet575]

If I just clean the posts and leave it off the charger then nothing happens. No new corrosion.

[Okie Boarder]

Is this battery one you've put on the same charger in years past and not had a problem with?

[augie]

It's strange the corrosion starts on marine batteries and your lawnmower battery. charger is suspect.

This wont' solve the problem, but you can always put these on your batteries. http://www.harborfreight.com/2-piece-battery-terminal-protector-96919.html?utm_medium=cse&utm_source=googlebase&hft_adv=40010&mr:trackingCode=F1780F9E-782A-E011-B31E-001B2163195C&mr:referralID=NA

One of my auto professors swore by them, like he was sponsored

[Suprahunter]

What setting are you charging at? possibly overcharging.

[Wheeler]

I always thought this was a reaction from the sulfuric acid. The old school fix was to clean the terminals and connectors with baking soda and water to neutralize the acid.

I cut the clamps that came on my charger and installed a cigarette lighter plug, then just charge through the lighter. I did this because my battery is difficult to get to. It works great, imposible to connect backwards.

[Okie Boarder]

Something else to think about is there are some theories out there about dissimilar metals, so your charger clamps versus the battery terminals could be contributing to this.

[pet575]

augie, that is not what is happening. It ONLY corrodes when I use it on the riding mower battery.


I'm not sure this is an overcharging condition. I've kept it mostly hooked up on the "maintain" setting except for the one time I suspected it to be discharged and then I put it on the rapid charge.


Okie Boarder, I'm going with your theory. I've seen that as well and thought about it. What confuses me is that the negative terminal is perfect and there is no corrosion on the battery charger's negative clamp. I've always made sure I had a good, tight, clean connection when hooking up the charger so I've eliminated that as a possible cause as well.

I'll probably just replace this battery this coming spring with a new one. These are just the cheap $30 batteries O'Reilly sells and it is a few years old now. Just wanted to make sure there wasn't some type of battery charger Jedi wisdom I was missing out on.

[Okie Boarder]

Ohhhh, you wanted Jedi wisdom?

[Okie Boarder]

[augie]

[kartman]

[pet575]

[Okie Boarder]

kartman, if that was done once, would it have been enough to create a recurring problem?