On Mar 4, 3:42*pm, "hr(bob) "
wrote:
I have a small battery-operated calculator that I rarely use, but when
I do need it, I want to be sure the battery hasn't run down. *The
button cell can be a LR54, LR1130, D189, RW89, 389, SR54, or one of
several other codes, *Either silver or alkaline. *Does anyone know
which type of battery has the lowest internal self-discharge?

Keep in mind, that a lot of battery chemistries have the following
quirk:

shelf life years!, unless...
measure the battery's voltage under load [in other words, use it once]
and a process starts that runs the battery down very quickly with
shelf life into even the 3 month range. [which means it's not good to
test the batteries in those emergency kits]

Anyone have numbers for this effect?