Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!husc6!psuvax1!vu-vlsi!cbmvax!grr
From: grr@cbmvax.UUCP (George Robbins)
Newsgroups: comp.sys.amiga
Subject: Re: Battery-Backed Clock Goes Back
Message-ID: <2307@cbmvax.UUCP>
Date: Fri, 4-Sep-87 22:27:20 EDT
Article-I.D.: cbmvax.2307
Posted: Fri Sep  4 22:27:20 1987
Date-Received: Sun, 6-Sep-87 02:02:59 EDT
References: <8708300822.AA20905@cogsci.berkeley.edu> <4410010@hpcvcd.HP> <261@uwslh.UUCP> <1@cc5.bbn.com.BBN.COM>
Reply-To: grr@cbmvax.UUCP (George Robbins)
Organization: Commodore Technology, West Chester, PA
Lines: 37

In article <1@cc5.bbn.com.BBN.COM> denbeste@cc5.bbn.com.BBN.COM (Steven Den Beste) writes:
> Chris Lishka writes:
> > 
> > Mr. Brown doubted that a Lithium battery could last 10-30 years,
> > stating that the life would be more like three years...well, I have
> > one of these buggers in a digital watch, and I've had the watch for
> > six years without having to replace the battery.
> 
> Sorry, that's a SILVER battery, not a LITHIUM battery.
> 
> Nonetheless, A project I was on at Tektronix used a large lithium battery
> (two inches diameter by an eighth of an inch thick) to back 4K of CMOS RAM.
> Our spec was guaranteed 7 years.
> 
> About the upper limit on NiCads is 100 charge cycles - less if the battery
> doesn't totally discharge between charges.

Look, batteries are a complicated subject.  If there was one kind that was truly
magic, than we wouldn't have to deal with so many varieties.

Lithium batteries are probably OK for most ultra-low power applications.  They
should last for the time most users are likely to have there equipment, however
some will fail early and some users will expect their equipment to last for
like to forever.

On the A500 I selected a Ni-Cd, because even though the performance might
deteriorate over the years, the cheapest (which is not the smallest) Ni-Cd
provides so much more capacity than the clock chip needs, that it should
work fine a long time from now.

Next time, perhaps we'll use a lithium battery, it really doesn't make that
much of a difference....

-- 
George Robbins - now working for,	uucp: {ihnp4|seismo|rutgers}!cbmvax!grr
but no way officially representing	arpa: cbmvax!grr@seismo.css.GOV
Commodore, Engineering Department	fone: 215-431-9255 (only by moonlite)