On Mon, 7 May 2007 12:29:11 -0400, "Robert11"
wrote:

Have been buying a bunch of those standard 9V batteries (a few different
brands) over the past few months, and have noticed that instead of 9V they
have been measuring out, with a VOM, at around 10.0 to 10.25. This is under
no load.


A battery cell is a chemical cell. The voltage generated varies with
the chemical concentrations and will decrease gradually from its peak
voltage until it is near chemically exhausted at which time there will
be a sharper drop. At exhaustion there will be chemical reaction
products that cause corrosion. The devices you use should be able to
operate at plus or minus 2 volts of the 9 volt nominal rating.