On 11/2/2005 at 12:10 PM Allison wrote:
Why not use a 2032 3V lithium coin cell? They are
cheap and small too.
For that backup use they should last years.
Tangentially OT:
I've got a friend who owns some rental property. When a tenant moves out,
he replaces all of the smoke detectors as a matter of routine. Because he
doesn't want to be bothered with replacing batteries, he equips all of them
with 9v lithiums. I've arranged for him to give me the castoffs, if
they've been installed for only a year or so (which is quite common). I've
got the batteries installed in everything from my garage door openers and
metronomes to my DVM. Great stuff and best when you get it for nothing.
One even serves as backup for my lawn sprinkler system's clock.