m Ransley wrote:
George do you mean lead acid is fully charged at 12.7 at 80f. I have one
rated for more but maybe 12.7 is the correct average, Nicads do peak at
1.32-1.35.


Yes, as Rich points out and provide a highly rated
link, the generally accepted figure is 12.65V for
a 12V lead acid battery, but not all sources use
that number and certainly most people can't
measure that accurately.

A new 1.5 alkaline dry cell usually reads 1.60V or
slightly. The NiMH and Nicads are considered to
be 1.2V cells, but a fully charged NiMH gets to
about 1.35V, and the common 7.4V Li-ion battery
reads 8.25V or so at full charge. OTOH, a NiMH
that reads 1.2V or a Li-ion battery that read 7.4V
is essentially depleted.

Using different kinds of batteries can be a bit of
a mess. Stuff made for alkaline cells, sometimes
just won't run on nicads or NiMH cells because the
appliance won't work when the voltage is below
1.25-1.3V. For example my GPS made for alkaline
indicates that freshly charged NiMH cells are half
discharged.