Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!seismo!ut-sally!husc6!bbn!cc5.bbn.com!denbeste
From: denbeste@cc5.bbn.com.BBN.COM (Steven Den Beste)
Newsgroups: comp.sys.amiga
Subject: Re: Battery-Backed Clock Goes Back
Message-ID: <1@cc5.bbn.com.BBN.COM>
Date: Fri, 4-Sep-87 09:06:11 EDT
Article-I.D.: cc5.1
Posted: Fri Sep  4 09:06:11 1987
Date-Received: Sat, 5-Sep-87 17:30:49 EDT
References: <8708300822.AA20905@cogsci.berkeley.edu> <4410010@hpcvcd.HP> <261@uwslh.UUCP>
Organization: Bolt Beranek and Newman, Cambridge, MA
Lines: 39

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.

The only kind of battery I know of that can stand up to continuous charge and
uncharge is a lead-acid (that's SULPHURIC acid) battery. They are BIG and
CLUNKY and DANGEROUS and let's not and say we did, OK? There are some newer
sealed lead-acid batteries intended for this kind of application, but they are
still substantially larger than a lithium battery (20-fold?).

About the upper limit on NiCads is 100 charge cycles - less if the battery
doesn't totally discharge between charges.

Of course, I could be wrong about this stuff... I just twiddle bits, I don't
grease the electrons...

> 
> -- 
> Chris Lishka                    /lishka@uwslh.uucp
> Wisconsin State Lab of Hygiene <-lishka%uwslh.uucp@rsch.wisc.edu
>                                 \{seismo, harvard,topaz,...}!uwvax!uwslh!lishka

-- 

     Steven C. Den Beste
     Bolt Beranek & Newman, Cambridge MA
     denbeste@bbn.com  (ARPA or CSNET or UUCP)
     harvard!bbn.com!denbeste (UUCP)

I don't think BBN cares what I think about this stuff.