"Gould 0738" wrote in message
...


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.


So what was the full charge standard before the advent of smart chargers?
Answer: 12.6v

Not to kick a dead horse, because if you're happy with 13.2v and I am happy
with 12.6v, then we're both happy -- but:

A charger has to develop a higher voltage than the battery voltage,
otherwise it won't charge. (Basic electrical rule of difference of potential
required for current flow).

Smart chargers in the bulk charge mode usually try to run in a constant
current mode with the voltage set at 14.4 volts for flooded batteries. The
absorption mode drops the voltage to 13.5 typically. Flood maintains the
charge at 13.5 volts (depending on charger manufacturer - I happen to be
looking at a Prosine unit manual at the moment) at very low current to
minimize electrolyte evaporation, but it is still charging. Remove the
charger and a flooded battery will return to it's normal state of 12.6v
within a hour or so. Try it. I just tested three known good batteries. I
charged each one with a smart charger that finished with a float charge
potential of 13.3 volts on each.
When I removed the charger, each battery read as follows within a couple of
hours:

Group 24 Marine Deep Cycle/Start Combination battery (flooded) --- 12.6v
AGM Deep Cycle Battery --- 12.8v
Two, U2400 six volt batteries in series (flooded, RV house batteries) ---
12.6v

According to your position on full charge, I must have three batteries that
are going bad which is not the case.


Eisboch

According to your position on full charge, I must have three batteries that
are going bad which is not the case.



You do not have batteries going bad because they can be charged to 13.2.

The fact that they then partially discharge to 12.6 doesn't make them bad
batteries.

If your batteries could not be charged above 12.6, they would be starting to
fail.
As you noted, they can be charged to 13.2.