'Frosting' on top of Ni-Cd batteries

[gubavac111]

Just wondering what this "frosting" on the Ni-Cd battery cap could be? How is it created? Is it dangerous? Should it be removed?

Check the pic below.

 

[Harald Kapp]

Looks like these batteries are leaking. You can remove the white stuff, but the batteries are degrading over time.
Are you sure these are NiCd batteries? From the look of it I'd say these are lead acid batteries.

 

[duke37]

Ni-Fe batteries will produce sodium carbonate fuzz.

 

[gubavac111]

Looks like these batteries are leaking. You can remove the white stuff, but the batteries are degrading over time.
Are you sure these are NiCd batteries? From the look of it I'd say these are lead acid batteries.

Definitely Ni-Cd batteries, installed in August 2018, still have a battery brochure.

 

[WHONOES]

Looks like the cells have valves on them to vent gases to atmosphere when they are overcharged or abused in some way. The frost is precipitated from the gas released and represents a loss of electrolyte which means reduced capacity.

 

[Bluejets]

Bit like the formation of corrosion on the positive of a wet lead acid cell.

Similar Ni-Cd were used in a pump station we used to maintain back in the 80-90's.

The difference was the interconnects were "plated" and kept clean to start with.
Then a smear of vaseline kept any terminal/connector corrosion caused by a combination of any escaping gases and use of differential materials (terminal to connector) at bay.

AS with lead acid, usually only the positive.

More info on wet ni-cd cells here.

https://batteryuniversity.com/learn/article/charging_nickel_based_batteries

 

[Warren]

Just wondering what this "frosting" on the Ni-Cd battery cap could be? How is it created? Is it dangerous? Should it be removed?

Check the pic below.

The electrolyte in Ni-Cd batteries is Potassium Hydroxide (KOH) solution. Slight leakage, especially when overcharged, occurs through "venting", after which evaporation of the water from the solution leaves a residue of the KOH. This "frosting" is quite caustic and should be removed with a mildly acidic solution, like vinegar. Avoid contact with the skin, and particularly, the eyes. As other commenters have noted, the deposits indicate loss of electrolyte and a corresponding reduction of the AH capacity of the cell.