Tips to Remove Alkaline Battery Contact Corrosion?

The first thing to try when removing battery snot is plain old water. If the plating is gone, you'll either have to replate or replace the contacts for reliable contact.

As has been suggested in a previous thread: (concentrated) white vinegar.

HTH

Reinhard

Dry corrosion/residue is best removed mechanically - once its clean enough for reliable contact, give it a squirt of silicone spray.

Don't try rebuilding contact surfaces with solder, oxidisation makes unreliable contact - sometimes its possible to graft on a strip of clean metal - solder it on, but don't get any on the contact surface.

Per KenO:

White vinegar applied with a Q-Tip worked for me the one time I had a similar situation.

Actually the EverReady battery engineer I spoke to back in the late 80s recommended white vinegar:water with a 50:50 ratio, not pure or concentrated white vinegar.

A weak acid to neutralize a weak base.

And as Peter W. so correctly pointed out, the common zinc/carbon battery leaks a mild acid and so you use baking soda (a mild base).

So be sure to identify the type of battery before attempting corrective measures.

John :-#)#

My experience: concentrated white vinegar achieves best results. But YMMV ...

FACK!

Best regards

Reinhard

Thanks everyone for your suggestions!!!

Will try to combine any questions.

"...identify the type of battery before attempting corrective measures" Unfortunately the person I received the electronic device from removed the batteries and does not remember if the batteries were zinc/carbon or alkaline.

Question: Can baking soda if used on the residue left by alkaline batteries cause additional damage?

Your initial post said alkaline batteries.

es cause additional damage?

For the most part, none of the items suggested here will cause damage, even if not the "ideal" solution. Vinegar at household strength is quite mild a nd will not cause horrendous damage to much of anything if used judiciously . Baking Soda is similarly fairly inert. Both have indirect virtues inasmuc h as they are effective anti-odorants as well as being reasonably effective germicides and fungicides. The key with using any water-based cleaning met hods on electronics is the complete removal of same at the end of the proce ss.

Peter Wieck Melrose Park, PA

"white vinegar" search

checked the top Google results but did not find any mention to either dilute with water or use full strength.

John and Reinhard do you have any references for your recommendations?

John-Del,

"The first thing to try when removing battery snot is plain old water. If the plating is gone, you'll either have to replate or replace the contacts for reliable contact"

I hope the plating is OK

Will plain water cause additional damage if the plating is damaged?

Ian,

"Dry corrosion/residue is best removed mechanically - once its clean enough for reliable contact, give it a squirt of silicone spray"

What do you suggest to mechanically remove the dry residue? It seems to be adherent to the contact surface (not loose and flakey).

Simple really. Alkaline batteries leave what looks like white fuzzy crystals. Some times with bluish green tint.

Zinc Carbon batteries leave what looks like rusty brown sludge. That is also spread about more and not confined to just the terminals.

Replace them with shiny new contacts:

If you plan to keep your "electronics unit", consider replacing the alkaline cells with rechargeable NiMH LSD (low self discharge) cells such as Eneloop. These types of cells can also leak, but in my experience much less often.

Terry,

"Your initial post said alkaline batteries" Agree, only when questioned found out unfortunately the person I received the electronic device from does not remember if the batteries were zinc/carbon or alkaline.

Jeff,

"Simple really. Alkaline batteries leave what looks like white fuzzy crystals. Some times with bluish green tint.

Zinc Carbon batteries leave what looks like rusty brown sludge. That is also spread about more and not confined to just the terminals."

Thanks for the clarification.

closer to 2nd Zinc Carbon

Any way it can attach a color photo? If yes please tell max size (will try to keep as small as possible).

Jeff Liebermann,

"consider replacing the alkaline cells with rechargeable NiMH LSD (low self discharge) cells such as Eneloop. These types of cells can also leak, but in my experience much less often." Agree have never had problems with either NiCd or NiMH.

You could test a small portion of the corrosion crystals with a drop of vinegar - if it fizzes then it is alkaline. For certainly test another bit with a drop of backing soda dissolved in water, this time it shouldn't fizz if the vinegar did.

John :-#)#

I'm afraid my information was in a telephone conversation back in the early 90s when I was investigating the best way to deal with ni-cad and other alkaline battery corrosion and called a number of battery companies (this was prior to the Internet). The advice given has been tested subsequently on countless pinball and video game MPU boards by many people and the results are positive. I wrote several articles in our industry trade magazines to get the word out, and have subsequently posted on my web site more info.

First posted in 1997:

It doesn't always work, the corrosion can be too extensive for economical repairs, but boards that have been treated as advised have rarely failed if they worked after cleaning (and corroded IC sockets, etc. replaced). Boards where traces are missing are normally too far gone, but have been saved with extensive repairs.

John :-#)#

What is the memory device? Some sort of CMOS RAM? Most are available in NVRAM these days...

John :-#)#