Path: utzoo!mnetor!tmsoft!torsqnt!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!uunet!shelby!msi.umn.edu!noc.MR.NET!gacvx2.gac.edu!hhdist
From: jsims@vuse.vanderbilt.edu (J. Robert Sims)
Newsgroups: comp.sys.handhelds
Subject: RE:  New life for NiCd (was Where can I get a battery pack for myTI-59?)
Message-ID: <9102160245.AA20231@vuse.vanderbilt.edu>
Date: 16 Feb 91 02:45:20 GMT
Lines: 21
Return-path: <jsims@vuse.vanderbilt.edu>
To: handhelds@gac.edu

Most of this article is accurate, but I see a few potential problems.  Some of
the charge/discharge rates are quite high.  Unless a NiCd is designed for a
quick charge, the charge rate should not exceed the amp-hour rating (i.e. 
rapid charging should happen in one hour).  Discharge rates should not exceed
this value by much (for a long period of time).  The internal resistance of
these batteries can cause them to overheat and be destroyed.  I have seen
Nicads catch fire from being overcharged.  

Trickle charge rates are capacity / 10 (what almost all chargers with one
charge rate use) and C/20 for maintaining a battery.

The caution about soldering quickly should also be heeded; Nicad manufacturers
say to never solder, to always spot weld; I haven't had problems (other than
adhesion) with quick soldering.

Digi-Key will make custom battery packs for a reasonable price (I think in
single quantities, too).

If their number isn't 1-800-digikey, it's in the 800 directory.

Rob
jsims@vuse.vanderbilt.edu