[Premium-Rx] Leaky Ni-Cads again.

[GandalfG8 at aol.com]

Hi All

As a follow up to my ealier 1650/9 posting a further problem with this set 
was the usual one of an unchanged Ni-Cad, same type as used in the Racal 1792, 
totally dead and starting to leak.
Fortunately I was able to remove it before it caused any significant damage 
but my thoughts on that lead me to a question.

I'm thinking of replacing this with a Supercap to avoid possible future 
problems but have also considered using three AA cells mounted away from the 
circuit board. I was thinking of potting them in epoxy resin or similar as another 
way of avoiding leakage problems.

Ni-Cad replacement has been discussed before but can't remember seeing any 
comments on potting the cells.
Does anyone know if this is likely to cause problems in normal operation?
Do they need to vent in any way?

They do seem to discharge gas when they've reached the leaking stage, judging 
by the corrosion I've seen that's quite distant from any physical cell 
deposits, so again would be interested to know if potting could cause problems under 
those circumstances.

I know the best answer is to change them regularly but just wanted to cover 
my back:-)

regards

Nigel
G8PZR


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