Where do you get this nonsense? "Open Circuit Voltage" is not the same thing
as
"Float Voltage." Did you even look at the link I provided, or are you
claiming
to know more about batteries than Trojan?


No I don't know more about batteries than Trojan.

However, if you test the batteries on your boat and you think that 12.6 means
the batteries are fully charged, that means I know more about batteries than
you.

I won't dispute that if a battery is removed from a charging system and allowed
to sit around in your garage, or languish on a retailer's shelf, the voltage
will drop. The initial drop may well be rapid, and 12.6 could be considered OK
for a partially discharged, idle battery. Put that battery back in a working
environment where it has access to charge from an alternator or a 110 charger,
and it will be "fully charged" when it achieves 2.2 volts per cell, or 13.2
volts total.

Rather obviously, the battery would not accept additional voltage if it was
"fully charged" at 12.6.

Since a "smart" charger will maintain a 13.2 voltage on a flooded, 12-volt
batery in good condition, that is the standard for full charge. If that same
charger cannot bring the voltage above 12.6, that's a likely sign that the
battery is beginning to fail.