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From: parnass@cbnewse.att.com (Bob Parnass, AJ9S)
Newsgroups: sci.electronics
Subject: Re: NiCad "Deep Discharger"
Summary: NiCds lose about 1% charge per day at 70 degrees F
Keywords: NiCad Discharge Memory
Message-ID: <1990Jun27.122406.26912@cbnewse.att.com>
Date: 27 Jun 90 12:24:06 GMT
References: <1990Jun15.154259.2666@ux1.cso.uiuc.edu> <9634@pt.cs.cmu.edu> <1990Jun26.194638.12467@vicorp.com>
Organization: AT&T Bell Laboratories, Naperville, IL
Lines: 20

In article <1990Jun26.194638.12467@vicorp.com>, ron@vicorp.com (Ron
Peterson) writes:

	> What is the shelf life of a nicad battery?
	> Are there any ways to improve it? (Store
	> in refridgerator, store charged/discharged,
	> store it in helium, store in a vacuum, ???)

No NiCd battery is perfect -- all have a finite shelf life.
NiCd batteries will discharge by themselves, through spontaneous
chemical decomposition, even when not connected to a load.
The General Electric Company indicates that the average
NiCd will lose about 1% of its capacity per day at 70 degrees F.

Average self discharge at 100 degrees is about double (2% per day)
the discharge at 70 degrees, which is a good reason to avoid
storing NiCd batteries in a warm automobile.
-- 
============================================================================
Bob Parnass, AJ9S - AT&T Bell Laboratories - att!ihuxz!parnass (708)979-5414