In Dan Master's Electrical Maintenance handbook he points out that, while
driving, the alternator
supplies a constant 14.6 volts to the battery, and once fully charged the
resistance prevents further charging. He also points out that in some
situation's, for example large
trucks, the engine is almost never turned off. That is, the alternator may be
supplying 14.6 volts
to that battery for days.
He puts out a disclaimer that he is no battery expert, but extrapolates from
his observations that
you probably can't over charge a battery with a battery charger.
Any comments out there?