Just to maybe add more fuel to the fire, when I measure the current into the
battery (flooded lead acid) from my fixed voltage (13.3 volts) float
charger, and the float charger has been floating the battery for days on
end, the continuous unchanging current is around 20ma. I guess my battery
is fully charged. The current is not going up or down and the voltage is
not changing. I can then conclude the internal leakage current of the
battery (while on float charge for days) is 20ma.

Also, when I remove the float charger and wait 24 hours for the battery
voltage to settle, it measures around 12.65 - 12.72 volts (depending on
which battery I measure) This is as measured with a DVM.

Have a nice day.....

"Eisboch" wrote in message
. ..

"Jeff Morris" wrote in message
...

A bad battery or a depleted battery may still read a high voltage when
connected
to a charger, and even for a while after being removed. All your
reading
of
13.2 tells you is that your charger decided to go into float mode. This
may be
a strong hint that the battery is fully charged, but it doesn't
necessarily mean
that.


Exactly. The best way to tell (other than checking specific gravity of
the
cells) is to also monitor the charger current delivered to the battery.
If
it is at it's float voltage (13.2v - 13.5v) and is still indicating a
small
current flow, then the battery voltage - which is a reflection of it's
apparent internal resistance - is less than the float voltage. A
difference
of potential must exist in order for current to flow. If the battery
charge
potential were the same as the charger float potential, the current meter
would read zero.

With due respect, I think this is where Gould's understanding is flawed.
The battery behaves like a variable resistance as it is charged, much like
a
large capacitor. For a given charge voltage delivered by the charger, the
current will vary (decrease) as it is charged).

Not to start this debate all over again, but I think Gould might be
surprised that while his voltage meter is reading the float potential of
the
charger, it is almost a certainty that there is still a small amount of
current flow - probably an amp or 2. This can only mean that the battery
has not come up to 13.2 volts.

Eisboch