[TriLUG] Linux laptop battery

[al johson]

The NASA engineer's article was published in QST magazine and discussed
whether or not the NiCad's used by ham radio operators ever suffered from
NiCad memory. He does a lot of mathematical calculations and basically
concluded that NiCad memory occurs in satellite batteries because they go
through very regular charging and discharging cycles (due to whether or not
there was sunlight on the "bird"). This never happens when people use
ni-cads because they are not that "mechanistic" in the way they use their
Ni-Cads. HE ALSO CONCLUDES THAT WHAT PEOPLE THINK IS NICAD "MEMORY" (which
is observed by the battery being unable to be charged to its normal voltage
and current)  IS ACTUALLY DUE TO POLARITY REVERSAL!!! The article is
available online at the ARRL website. Find a ham who's an ARRL member and
look it up, if you're really interested.
----- Original Message -----
From: Chris Merrill <cmerrill at nc.rr.com>
To: <trilug at trilug.org>
Sent: Wednesday, February 06, 2002 7:53 AM
Subject: Re: [TriLUG] Linux laptop battery


> al johson wrote:
>
> > You should also NEVER run Ni-cad or NI-MH batteries until they are dead
> > either!! If you do, you will risk reversing the polarity of one of the
cells
> > and the battery will never recharge properly again. (a battery is
composed
>
>
> Either this is not true, or the chance of it happening is very,
> very small.  I have always fully drained my NiCad batteries after
> use prior to storage or charging.  A few particular sets (used in
> a walkman during college) went through literally _hundreds_ of
> cycles - most of which had a _full_ discharge: which (for me)
> meant discharge to the point where they would not even warm
> the filament of a 3W light bulb.  I have NiCads that have been
> used in this manner for >10 years - and they work fine.
>
> I have never heard of 'reversing the polarity' of a dry cell,
> or any other battery, for that matter.  From what little I
> remember from chemistry 101 it is not chemically possible in
> wet cells.  I am very interested in this 'reversing polarity'
> concept - Do you have some sources of information on this?
>
> I'd also like to see the NASA research paper...since I have
> seen research to the contrary (I wish I had a copy...).
>
> *********************************
> Chris Merrill
> cmerrill at nc.rr.com
> *********************************
>
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