"Steve" wrote in message
om...
I think complex electronic regulators is a step in the wrong direction.
The whole idea of the Manual Alt. Control (MAC) is to override the standard
alternator regulator. Reason being, the standard regulator starts 'tapering
off' long before your battery is fully charged, assuming you will be
running your engine for many hours, as in an automobile. The real world on
a sail boat, you want to charge a large battery bank in short order so you
can secure your engine and enjoy the piece and quiet of sailing or your
anchorage.

The MAC allows you to charge at a higher amperage until you observe the
proper voltage level. It also allows you to raise this voltage for a short
period for the occasional equalization charge. With care all of these
functions can be accomplished with the simplest MAC.

Most modern regulators (more accurately called a Charge Controller) do this
automatically. One can't manually do as good a job as a good 3 stage
automatic controller. That is, if you want to maximize the lifetime of the
batteries as well as get a good charge in a minimum of time. I seen several
boats that have trashed batteries trying to manually control charging. Just
not worth it.

C.Plath, following Edgar Beyn's (author of 12volt Doctor's, etc) designs,
developed the AutoMac and the AutoMac II which gradually became more
complex. This complexity, however allowed semi automatic charging that is
better suited to the needs of a boater with high demand and deep cycle
batteries.

I have been using the AutoMac II for 3 years and it works flawlessly.
However, it will over work a automotive alternator since they aren't
capable of producing their rated output for extended periods of time. Even
at 80% of rated capacity I burned out two this summer. One went from
overheated brushes and the other was due to burned out stator. I think I
could have avoided the latter if I had installed the AutoMac temp sensor
on the alternator case. (lost that some place over the years).

The C.Plath AutoMac and AutoMac II is no longer made and I purchased mine
over 10 years ago but only installed it on this boat 3 years ago. It is
much more complex than the old MAC described in these books. It is solid
state and well built, with mostly automatic function in all charging
phases.

Here is a link to the installation and operation manual for the AutoMac
II.
http://www.hctc.com/~esteve/INGRID%2...s/cplath~1.pdf

Perhaps you may find one at a swap meet or on eBay. I know I don't want to
sell mine.


--
My experience and opinion, FWIW
--
Steve
s/v Good Intentions