Newsgroups: sci.electronics
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: Long-Life battery and clock
Message-ID: <1988Dec10.234303.26780@utzoo.uucp>
Organization: U of Toronto Zoology
References: <1310017@hpcilzb.HP.COM>
Date: Sat, 10 Dec 88 23:43:03 GMT

In article <1310017@hpcilzb.HP.COM> doug@hpcilzb.HP.COM (Doug Hendricks) writes:
>1.  A battery that can be trusted after 100 years of storage,

100 years of *storage*, or 100 years of low-level *use*?  If it's not
required to produce current during those 100 years, almost any of the
schemes which separate solid and liquid components until activation
would do.  For example, an ordinary lead-acid battery with the acid
stored in a glass container until activation time.  Actually providing
current for 100 years would be much trickier; better would be to have
a set of good separate-component batteries activated in succession, so
an individual battery isn't required to be active that long.

>2.  A clock of some sort to alarm after 100 years.

This should not be hard if you can supply power.  I'd guess that high-
reliability digital electronics should last that long, especially if you
make it triple-redundant against minor failures.
-- 
SunOSish, adj:  requiring      |     Henry Spencer at U of Toronto Zoology
32-bit bug numbers.            | uunet!attcan!utzoo!henry henry@zoo.toronto.edu