HP Forums
What is that white stuff in the battery compartment? - Printable Version

+- HP Forums (https://archived.hpcalc.org/museumforum)
+-- Forum: HP Museum Forums (https://archived.hpcalc.org/museumforum/forum-1.html)
+--- Forum: Old HP Forum Archives (https://archived.hpcalc.org/museumforum/forum-2.html)
+--- Thread: What is that white stuff in the battery compartment? (/thread-210416.html)



What is that white stuff in the battery compartment? - Kees Bouw - 01-29-2012

A recently acquired HP-65 has white staining in the battery compartment, presumably from a leaked battery. I can't get it off. I tried to remove it with swabs with only water, but after it dried up it seemed worse. Then I used lemon juice, from a small bottle that is normally used for cooking. That did not do much at all. Before I move on to more aggressive solvents, I thought I would ask if anyone here knows what exactly the white stuff is, and how it can be removed.
On the same topic: which chemicals leak from a NiCd battery in general and how toxic or aggressive are they? Is there cadmium or a cadmium compound coming out at some point?


Re: What is that white stuff in the battery compartment? - Lincoln R. - 01-29-2012

Ordinary white vinegar will dissolve that stuff, although you want to make sure you clean off all the vinegar with something (distilled water, isopropanol, etc.) afterwards.


Re: What is that white stuff in the battery compartment? - From Hong Kong - 01-30-2012

Quote:
A recently acquired HP-65 has white staining in the battery compartment, presumably from a leaked battery. I can't get it off. I tried to remove it with swabs with only water, but after it dried up it seemed worse. Then I used lemon juice, from a small bottle that is normally used for cooking. That did not do much at all. Before I move on to more aggressive solvents, I thought I would ask if anyone here knows what exactly the white stuff is, and how it can be removed.
On the same topic: which chemicals leak from a NiCd battery in general and how toxic or aggressive are they? Is there cadmium or a cadmium compound coming out at some point?

I used antiseptic alcohol to remove those stains in three occasions and the results were encouraging. It's because:
1) it isn't corrosive to metal;
2) it dissolves both organic and inorganic compounds; and
3) it evaporates rapidly

I hope my experience can help! :)

The white stuff may be the oxides or hydroxides of cadmium.


Re: What is that white stuff in the battery compartment? - Kees Bouw - 01-31-2012

Quote:
The white stuff may be the oxides or hydroxides of cadmium.

I sure hope not, because cadmium is very poisonous.


Re: What is that white stuff in the battery compartment? - Ed Look - 02-01-2012

If there is a suspected leakage of material from a nickel-cadmium battery, then also suspect that it is toxic. Touching a small amount won't hurt you; but do wash your hands and do not ingest any. This sounds silly, but grown people do lick their fingers when they need a little more grip, for example. Do wear thin latex or nitrile gloves. Water will remove it better than alcohol, but in the case of the former, don't use much, just a damp paper towel.

I would recommend also that you do not dispose of the used paper towels, etc. in the trash, if there is a lot of it. With just a smear or little bit of the "white stuff", then it should not be problem.

Cadmium is an internal organ poison and nickel... well, it's not good for you, either, but it's less of an issue than cadmium.