-=> Andy Ball said to Greg Mayman
 -=> about "SILICON CHIP ON LINE" on 05-19-04  21:14.....

 AB> For low-current, long-life applications I tend to go for Zinc/Carbon
 AB> cells.  Was there a reason that you chose Alkaline ones (convenience?)?

There sure was a good reason.

Carbon/Zinc cells age even when they are not being used, and
most times they don't last more than a couple of years.

I have had new ones (unused) that were useless in less than 12
months at room temperature, and these were a reputable brand, not
supermarket cheapies.

You _can_ make them last longer if you keep them in the
refrigerator, but that's not practical for a CMOS backup battery.

Alkaline cells have a much longer shelf life. I have seen figures
quoting less than 10% loss after ten years at room temperature.

That's the reason why I recommend them for CMOS backup.

   ,-./\
  /     \ From Greg Mayman, in beautiful Adelaide, South Australia
  \_,-*_/    "Queen City of The South"    34:55 S  138:36 E
       v

... A beer doesn't get jealous when you grab another beer.
___ Blue Wave/386 v2.30

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