.... I would have thought that a well built system
would
prevent overcharging even if you had only one battery.


True

He didn't mention having a "well built system", simply a typical 1-2 All
battery selector switch, which does nothing to regulate charge.

Also true, but not necessarily relevant. The usual
"1-2-Both" rotary switch is almost a guarantee that you will
have a dead battery at some point in the use of the boat,
and probably blow up your alternator as well.

.... I would have
thought that if he had a "well built system" he would have nmentioned it and
indeed, probably never have asked the question in the first place, as he
would have had no need to. Which reminds me of the fact that I don't have a
"well built system" on my own boat, possibly a project to tackle this year.


A smart charger is very well worth the money even if you
just overnight occasionally.


OzOne wrote:
John, the regulator regulates charge.


Umm, no. Unless it's a smart charger, all it regulates is
voltage.

Most alternators have the voltage regulator built into the
stator, which means that it sense voltage at the output of
the alternator, not on your battery. This guarantees that it
is not getting charged as much as it could, because the
voltage at the output is higher than what your bettery
actually gets. Then, most regulators work on a resistance
curve that does not bring the amperage down at the right
curve for charging as the battery voltage goes up. Usually
the voltage will go too high, which means it's boiling off
the battery electrolyte.

Fresh Breezes- Doug King