Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!mcdchg!chinet!ignatz
From: ignatz@chinet.chi.il.us (Dave Ihnat)
Newsgroups: comp.sys.laptops
Subject: Re: Zenith supersport 286 battery
Summary: Could be bad...
Message-ID: <1990Jul19.165921.24576@chinet.chi.il.us>
Date: 19 Jul 90 16:59:21 GMT
References: <1990Jul17.131027.1976@vaxa.cc.uwa.oz.au>
Organization: Chinet - Public Access UNIX
Lines: 44

In article <1990Jul17.131027.1976@vaxa.cc.uwa.oz.au> a_schwartz@vaxa.cc.uwa.oz.au writes:
>I am having difficulty in getting a full charge into the battery
>which comes with my Zenith Supersport 286(20 mb hard disc).  ...
>on, which involves no hard disc use after initial connection.
> ...
>Can any Zenith or laptop mavens out there tell me:
>(a)What have I been doing wrong?

Probably not a lot.  You shouldn't charge over about 12 hours, however.

>(b)Can this battery be restored to taking a full charge, and if so, how?

If you go through three full charge-deep discharge cycles (all the battery
watch program is doing is activating all the peripherals it can to maximize
current drain), and it doesn't recover, accept that you've a fatality.  It
happens...

>(c)Is the battery harmed by leaving it on the 286 and hooking up to mains
>   power through it?

I've never had a battery go bad by doing that--and I've had a Z-171, Z-181,
and now a Supersport 286 20Mb.  It *does* take a trickle charge while in
use, though, so it's probably not a bad idea to drop it out of the circuit
if you're using the machine all day, every day (or at least often.)

>(d)Just what is meant by "memory-effect" problems with nicads?

This is, believe it or not, a somewhat shaky assertion that has *not*, despite
much rhetoric and "accepted wisdom", been reliably proven.  It had been
observed that some nicad batteries, if taken through a series of shallow
charge-discharge cycles, tended to lose power much sooner than if taken
through a full charge-discharge; and this reduced capacity seemed to reflect
the levels that had been encountered in the shallow cycles.  Thus, the
warnings, and utilities to force deep discharge, etc.  In point of fact, it
was mentioned in an article I read a couple of weeks ago (sorry, I *don't*
remember the 'zine; I read dozens, and it's in a stack at home) that this
assertion has NOT been rigorously tested using a statistically meaningful
sample of commercial batteries.  (But, on the other hand, it costs little
to follow the guidelines, and a lot if it *is* true and you scrag your
battery.)

>(e)Is there a Zenith dealer in Perth?
Gee, sorry, can't help you there.  I could pick one up here in Chicago
and mail it to you...