It's amazing how some batteries can last so long. I originally posted this a couple of years ago:
Our front doorbell recently stopped working, and on investigation I found that one of the four C cells was open circuit. The remaining three all read slightly under 1.5v. These batteries had never been changed since the doorbell was first fitted in 1996! And not a sign of corrosion or leakage.
At the other end of the scale, my digital micrometer seems to drain the tiny mercury battery stone dead even when not in use....
