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Path: utzoo!watmath!sunybcs!palisano
From: palisano@sunybcs.UUCP (Tom Palisano)
Newsgroups: net.consumers,net.physics,net.analog
Subject: Re: lifetime of rechargeable batteries
Message-ID: <888@sunybcs.UUCP>
Date: Wed, 28-Nov-84 02:26:39 EST
Article-I.D.: sunybcs.888
Posted: Wed Nov 28 02:26:39 1984
Date-Received: Wed, 28-Nov-84 07:41:59 EST
References: <1789@garfield.UUCP>, <150@geowhiz.UUCP> <284@cadovax.UUCP>
Organization: State University of New York @ Buffalo,NY
Lines: 35

> >>         I have recently bought a set of GE size  'D' rechargeable
> >> batteries  and  have had to recharge them twice in the past month
> >> and a half.  When I first bought them, I charged  them  up,  used
> 
> >  I just bought a 9 volt nicad battery and found out that 9 volt 
> >nicads really only produce 7.2 volts.  Thats fine for my application,
> >but are there some common appliances which won't work with 7.2 volt
> >nicads, but will work with regular 9 volt transistor batteries.
> 
> It's obvious that the battery manufacturers just can't bring themselves
> to produce a product that would effectively obsolete their disposable
> battery products.  I remember some battery packs in some of the Tektronix
> scopes that seemed to last for years. 

		The problem with NiCads is that by nature they only
produce ~1.25 volts/cell as opposed to carbon cells @ 1.5 V/cell.
NiCads also tend to have 'memory' with regard to how they were/are used.
A battery that is recharged before it is fully exhausted will remember this
and give limited service once charged. In addition NiCads are not ment
to be used in a parallel combination due to their low internal resistance.
		These factors lead to problems when batteries of this type
are used as replacements for standard non-rechargeable cells.
		Perhaps a better solution would be to use Lead-Acid 
cells that produce about 1.7-2.0 V/cell and have none of the quirks that
a NiCad exhibits.

				Tom Palisano



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Tom Palisano       uucp:[bbncca,decvax,dual,rocksanne,watmath]!sunybcs!palisano
csnet:palisano@buffalo 
arpanet:palisano.buffalo@csnet-relay
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