15 Aug
2006
15 Aug
'06
9:33 a.m.
Allison wrote:
The shelf life (self discharge rate) of most batteries is *MANY*
YEARS. The AAA cells I bought last year for my Visor have a
"expiration date" of 2013.
A low power BBRAM design essentially falls below this self
discharge rate (unless you get sloppy with the design).
The real problem is ensuring that the batteries (i.e. the
equipment that they are stored in) doesn't sit in
temperature extremes, high humidity, etc.
And, if you're storing your '8 in those conditions, I suspect
one of these days you'll be in for an unhappy surprise as
you "suddenly" discover components that have fatigued
Subject: Re:
PDP-8 /e/f/m memory
From: Don <THX1138 at dakotacom.net>
Date: Mon, 14 Aug 2006 20:50:25 -0700
To: General Discussion: On-Topic and Off-Topic Posts <cctalk at
classiccmp.org>
Chuck Guzis wrote:
Because most batteries have shelf life! The average battery dies in
a few years from just sitting. The LI cells are designed for very long life.
I have a few sub-C sized LI cells that are over 15 years old and going strong. On 8/14/2006 at 7:25 PM Bob Rosenbloom wrote:
Why not use a *big* battery/cell...
aren't we talking
about a design that would end up WAY undersized? Even
scaled would leave lots of real estate that you could
install a conventional AA, 9V, etc. battery and forget
about it "forever" How about two Ramtron FM18L08's? Nonvolatile
like core with no battery
to die or leak. Would need level shifters to 3.3 volts
and slightly different timing. Low power, and in DIP or SMT. I'm just
tired of cleaning boards that had batteries that leaked all over them.
How long
will a supercap keep that much SRAM alive?