Electrical: White stuff in the battery tray

[Michidan]

The last few years I've been getting a lot of corrosion in the battery tray. The same white by-product you would see from really old AA batteries. I suppose it means the battery has a leak, but it sure doesn't look like it.
I'm replacing the battery and cables this week. But while I'm at it, would there be any other cause, a problem with the wiring or a drain, that would lead to this kind of problem?

[warrlaw1]

That's pretty common. S.I. sells a pad that goes under the battery and is supposed to neutralize that stuff so it doesn't corrode the tray and inner fender. I have one on mine and the corrosion has been minimal. Good luck, Dan.

[TWChamp]

Some MoPars in the 80's had shallow battery trays under the battery. I pick them up at junk yards and use them to save the metal from corrosion. Overcharging can lead to acid bubbling out the caps. I smear Vaseline or grease around the battery posts to help prevent corrosion.

[Michidan]

To fit in the big motor my battery try is homemade and in the rear passenger corner of the engine compartment. I designed it to hold the battery down by the bottom ridges. (and we all know how important a battery hold down is.) But because of this I have a height limit for putting in a pad of some sort.
I have a thin sheet of plastic down already but it was not helping.

[sweetolbob]

Check alternator output and voltage regulator to be sure it isn't over charging.

[Michidan]

That seems likely. What can you tell me about it ...what's normal? Voltmeter always sits around 15 V running. I put a 94 amp alternator on it thinking I would run an electric fan, which I do not. In fact I run basically no electric accessories at all. Car doesn't even have a radio.

[doofus]

According to a reputed batt rep this is caused by gasses leaking around the batt posts. look for color coded, treated felt washers at your flaps, they have helped. Luck Doofus

[Lynn]

IMHO 15v is too high. 13.8 to 14.2 is what you want with no load.

[Skip Lackie]

According to a reputed batt rep this is caused by gasses leaking around the batt posts. look for color coded, treated felt washers at your flaps, they have helped. Luck Doofus

Yes -- what doofus said. The white powder on the battery post is lead sulfate (mixed in with a bit of sulfuric acid), and is created by the hydrogen gas that is created when the battery is charging (especially when it is overcharging) pushing tiny droplets of sulfuric acid out of the battery, where it reacts with the lead posts. If it's blue-green, it has some copper sulfate in it too. If it's on the battery tray, it's iron sulfate. The GM side post batteries were supposedly designed to reduce this problem, though they created other problems of their own (they're hard to jump). Any FLAPS will have the felt washers (treated with something alkaline and a bit of oil) that should reduce the generation of the powder.

[53commander]

IMHO 15v is too high. 13.8 to 14.2 is what you want with no load.

I agree with this, even a higher amp alternator should limit the charging voltage.

[T.J lavallee]

Don't forget to clean your battery tray with baking soda dissolved in a small amount of water in a bowl and a small scrub brush. Wipe the area dry with paper towels after.

[Michidan]

Thanks all. Working on getting it fixed up.

[Lynn]

Used to be the really good quality batteries rarely had issues as long as they were not being overcharged, and were maintained properly.

Seems about 15 years ago, I couldn't find a battery that didn't either leak or corrode way too fast. Yes, there are some band aids. The mat helps. The green and red rings help if saturated in something that neutralizes battery acid. Most of the time, I just use an Optima when possible. You could mount it upside down, and it won't leak or corrode. I have seen multiple posts in the last couple years complaining about the Optima quality has gone down hill drastically. I have several in service, and just put one in a car a few weeks ago. Fortunately, I have not had any issues with them. No more "fungus garden".

[Hallabutt]

Use an Optima battery and problem will go away!