Powder on battery terminal

[Olly75]

Would anyone hazard a guess as to what the white/greenish powder is around the positive of my Genny starter battery?

I've hopefully attached a photo of it.

[Bleemus]

Either someone tried to neutralize battery acid with baking soda or it's corrosion. Pull the red tape off should should show if it's corrosion.

[Wotname]

Corrosion and probably due to overcharging as it is mainly on the positive terminal. Clean with hot water and apply a simple low pressure grease like Dow Corning #4 (DC4).

A good explanation can be found here https://mechanics.stackexchange.com/...inal-corrosion

[john61ct]

Also check for any electrolyte seepage, micro-cracks in the casing around the post.

If you do use baking powder with the hot water to neutralize the acid when cleaning, make **very** sure none gets into the electrolyte.

[Dave22q]

On automobiles my experience was that coke worked well. Just pour on and after an hour or two rinse with fresh water.

[hellosailor]

Looks like a "maintenance free" aka "maintenance is not possible" battery. Which is good in that you can't get garbage into the cells while cleaning it. Close up that looks like someone dumped baking soda on it to neutralize acid, and acid shouldn't be an issue with sealed batteries anyway.

So, plain tap water and a toothbrush to clean it all off. (If it isn't sealed, make sure it doesn't get into the cells.) When it is all clean shiny and dry, reassemble the cables to the terminals using just a dab of antiseize or grease, preferably silicon grease because that doesn't migrate, and tighten up.

To prevent future corrosion (copper in salt air) you can coat them with a vinyl dip, or apply a little grease, or get a "battery spray" aerosol can, which applies a protective coating. Many ways to skin the cat, but that kitty litter box needs to be cleaned up first.

[Olly75]

Thanks all

Yes, its a maintenance free battery, so that should make it slightly safer to clean up. Its not currently cranking the genny so will give it a good clean and see if that makes a difference......

[john61ct]

Look for cracks, wiggle the posts

[Mistress Sirena]

I was hoping for a more detailed explanation I also have some crud on my 2 year old Trojan batteries. any more technical advise? yes there seems to be a little seepage around posts.

[john61ct]

What sort of more details?

The case is cracked, seeping electrolyte fluid.

I would replace, but others may tell you how to patch them up get a couple more years.

Are they firmly fixed in place or maybe been tossed around a bit?

For prevention, should be no stresses on the posts nor their connections.

[boatpoker]

Get rid of the wing nut on the negative post and put a fuse on the positive post.

[DockDoc]

This a base substance, likely baking powder. I t has been applied and is not the result of electron transfer, electroplating or otherwise. The fact that it has accumulated on the rubber insulation of the cable coming in confirms this, as does the "splatter pattern". Someone has tried to abate acidic corrosion by apply a base powder. Clean it off and observe for hydrogen gas generation (bubbles) when charging.
You can use coke ( a mild carbonic acid) to clean, soda water would work just as well, or any carbonated not citric soda.

[Uncle Bob]

Originally Posted by DockDoc

This a base substance, likely baking powder. I t has been applied and is not the result of electron transfer, electroplating or otherwise. The fact that it has accumulated on the rubber insulation of the cable coming in confirms this, as does the "splatter pattern". Someone has tried to abate acidic corrosion by apply a base powder. Clean it off and observe for hydrogen gas generation (bubbles) when charging.
You can use coke ( a mild carbonic acid) to clean, soda water would work just as well, or any carbonated not citric soda.

Interesting, how does one check for bubbles when charging a sealed battery?

[Bleemus]

Originally Posted by Uncle Bob

Interesting, how does one check for bubbles when charging a sealed battery?

You are looking for cracks around the post. The bubbles will be apparent if they are cracked.

[john61ct]

I've had that powder from electrolyte seepage then evaporation only.