[Premium-Rx] Leaky Ni-Cads again.

[Carcia, Frank A. HS]

    Take a look at portable phone batteries is shrink sleeve with
wire leads. You just have to cut off the connector and solder the leads to
the board. I would not pot a battery. Sneak in the kitchen
   and look for the correct plastic container while the XYL isn't
looking. I think they come in 1 to 4 cell packs. Each cell is around
is just above 2 volts. Radio Shack has lots of them  fc

-----Original Message-----
From: GandalfG8 at aol.com [mailto:GandalfG8 at aol.com]
Sent: Wednesday, August 06, 2003 3:18 PM
To: premium-rx at ml.skirrow.org
Subject: [Premium-Rx] Leaky Ni-Cads again.


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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