Wet cell battery stand-by longevity is longest when the battery is not held at peak charge. That means bringing the battery up to 13.8-14.1 volts, holding it there for a few minutes to a few hours for equalization and plate surface conditioning. Then the battery is maintained at a float voltage of 13.2 or 13.4 volts, adjusted for temperature.
Batteries in cycle service (e.g. golf carts, sailboats) are best charged hard to a higher level (even 14.4V), and then held at 13.8V or so. Only a few chargers are "smart" enough to allow the voltage to drop back to 13.2V if the battery isn't used for a week or two.
The magic in the charging is during plate equalization and conditioning. Pulsing the voltage, even to the point of a little discharge, can improve the usable capacity of a degraded battery.