[FARC] ni-cad cells

[Ernest Hansen]

Hey Rolan I will be interrested in them.
Check out my web page. It is still under
construction:  
http://erniehansen.tripod.com/index.html
Ernie 

--- On Thu, 3/4/10, Rolan O. Clark <rolan.clark at comcast.net> wrote:


From: Rolan O. Clark <rolan.clark at comcast.net>
Subject: [FARC] ni-cad cells
To: "FARC reflector" <farc at mailman.qth.net>
Date: Thursday, March 4, 2010, 7:17 AM


All,

I have 50 plus 10Ah  Ni-Cad  cells that anyone can have.   They still have the shorting wire across the terminals and the recommend way to restore them is to charge at 1/100 the normal AH rate until initial  charge is reached.  Each cell is about 4 x 6 x 1 inches.  Each cell should be in clamp to keep them from expanding while  charging.

The initial charge rate would be .1 amps till  charged.  

Then the normal  charge is Ah/10  rate, or in this case 1 amp, till they reach the full  charge V and like all Ni-cads it is recommend that they be close to fully discharged before recharging so  they don't  exhibit  the 'memory' problem.

I will take them to the special collection by the county on May 22, I think it is,  if no one wants them. 

They may be 20 Ah cells but I think to be safe treat them as 10 Ah cells until they have charged and you can discharge them to see what their capacity is.  One rule of the thumb for Ni-Cads is the Ah capacity should be   .75 Ah rating for  .75 hr so,  if  a fully charged cell will go from full charge   to  1.1 V  with a 7.5A load for 45 minutes then it is at least 10 AH.

You could discharge a fully charged cell at 15A  (20Ah X .75 = 15A) and see how long it  takes to reach discharge, probably 1.1 would be discharged, and if the charges  lasts 45 minutes then it is  a 20Ah cell. 

Take care,

73 de rolan w3fdk 
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