Path: utzoo!attcan!uunet!husc6!ogccse!blake!uw-beaver!fluke!strong
From: strong@tc.fluke.COM (Norm Strong)
Newsgroups: sci.electronics
Subject: Re: Long-Life battery and clock
Message-ID: <6288@fluke.COM>
Date: 12 Dec 88 18:50:38 GMT
References: <1310017@hpcilzb.HP.COM>
Sender: news@tc.fluke.COM
Organization: John Fluke Mfg. Co., Inc., Everett, WA
Lines: 21

In article <1310017@hpcilzb.HP.COM> doug@hpcilzb.HP.COM (Doug Hendricks) writes:
}A friend of a brother of mine is an artist who is interested in two items:
}
}1.  A battery that can be trusted after 100 years of storage,
}
}2.  A clock of some sort to alarm after 100 years.
}
}Obviously, shelf-life is the primary concern.
}
}I thought of NASA-type fuel cells for number one, but am not sure
}if they would truly be appropriate.

I would recommend lithium-iodide cells--lots of them.  The shelf life is 20
years to 80% of capacity.  After 100 years, the capacity will be down to 30%.
That's plenty good enough for a CMOS clock.

If you don't like that one, try a radio isotope battery.  These are available
for a variety of lifetimes, depending on current drain.
-- 

Norm   (strong@tc.fluke.com)