Tim wrote:
John, yes...it IS fun. takes away from the humdrum of typical shop
work. it's relaxing actually, to work on this boat. Especially seeing
I'm in the Auto-Electric business, I get my stuff wholsale.. LOL!
Even though this additional electrical stuff didn't really need to be
done, (except for the bat. isolator, and a bit of freshening up) I'm
likeing putting it to the way I want.


I thought something was a bit odd, when I was looking around the engine
ont he Monarch. Somebody ahd swapped out the alternator with an earlier
non-integeral regulated Prestolite!

GAG! I hate those things! The origional Motorola probably went south,
and so someone took this off an older boat that was equipped with OMC.
OMC used a bunch of goofy engine combinations and for some unknown
reason, chose Prestolite to be their electrical supplier. Not really
hard to work on, but parts are becoming scarce and expensive.

Whoever wired this thing in, I commend them on their genius of
"rigging". I will say they did a neat job, And they also did something
I'[ve done before like in the "old days" of converting old 6 volt
generator'd tractors over to an 12v alternator system. is the Pos. wire
attached to the back of the alt. to the output stud as usual. but
instead of using the stock volt regulator. somebody used a Volt. reg
for a '66 Dodge. Yep! "LeDodge!"

They're cool. the little matchbox VR is so simple, one wire from the VR
goes to the alternator "Field terminal" and the other side of the VR
goes to the key switch.

About as simple as you can get, and cheap "riggings" too! But thats
OK. With a tear of grattitude, in the barrel it went and got replaced
with a homebuilt 90A 12SI Delco! Oh yes, I DO install the spark
arresting screens.

I thought, well, while I'm here, I thought to myself. Eh, Pull the
starter. So, down I go with wrench's and rachet in hand and pulled the
heavy beast off. "That's what I thought... Low-torque POS!!! "

So, to the shelf I go and get a new permanent magnet (PMGR) 260
Delcostarter which weight about a thrid as the origional, and has over
50% more cranking speed and torque. Grab retro-bolt kit housing gasket
(to compensate and fill in for the smaller nose in the larger flywheel
bellhousing opening), and installed the new starter with ease. A whole
lot easier than taking the other one off.

The old Starter was "OK, but needed some lube , brush's and bushings.
and the brush springs were about rotted off, but not a big deal, but I
hitt the key on the new one, and it cranked so much better! I knew it
would crank better than the old one's wildest dreams. I love it!

Hmm time to investigate the other battery. I found out why there wasn't
an auxillary battery in the other battery box. Why no Aux. battery?
Because the battery isolator was bad....figures!
I never liked them either, I always thought it was an odd way of doing
things. So... the isolator becomes surgically extracted. And I make my
own. I lilke mine better.

"Run" battery pos. terminal Cabled to starter Solonoid. neg. terminal
to engine block., 10 guage wire from Starter solonoid battery terminal
to Alternator output stud. (Typical, and simple),
Next. Auxillary Battery pos. running through a Motorola isolation diode
plate , with 3 press fit diodes with 50a.ea. rating, (pulled off a
junker John Deere combine alternator) bridged in between "Run" battery
pos(via. 10 ga., and "aux" battery pos. ."Aux" battery neg. to engine
block(via 10ga).

Really simple. Only drawback is there is a slight voltage drop on the
aux. battery charging due to natural inefficiencies in the diodes. So
instead of the 14.-14.2 v that the "Run is getting" the "aux" will
suffer at 13.5-13.8 v. boohoo.
plenty to keep lights, radio, kids DVD, etc working for hrs. and no
drain on the "run" bat. And if the "aux" is drained it should re-
charge with no problems. So, until the Pertoronix electronic ignition
kit comes in, I gurss I'll get back to working on the cuddy interior.
man, I like doing stuff like this!

JohnH wrote:
And it sounds like you've got a good handle on what you're doing!


Tim, I think you have a small problem . . .

So you've got the Aux battery fed off the engine battery via a diode.

This means that any load on the Aux battery will drain *BOTH* batteries
as if the Aux is lower than the engine current flows through the diode.
*NOT* what you wanted.

If you want to make this work, you'd need to reverse your isolator diode
plate and take the alternator output direct to the Aux battery.

Why not fit a combiner? either a commercial offering or 'roll your
own'. On our small yacht we have a 'rool your own' combiner consisting
of a pair of 40A relays in parallel (I was too cheap to get a proper 70A
relay) protected by a 70A fuse. It joins the +ve terminals of the Engine
and Aux batteries but only when the Alternator warning light goes out.
There is a simple circuit with a power transistor connected to the
warning light terminal of the alternator to drive the relay coil. This
is because if the relay coil was connected direct to the warning lamp,
the lamp will never go out properly. There is also a switch to let me
select Auto, Off or Forced. In the usual Auto position, the relay cuts
in when the engine key switch is on and the alternator charge warning
light has gone out. It drops out again as soon as the charge light
comes on when you stop the engine.

Its been running all this year with no trouble. We put the Aux battery
switch on when we go down the boat and turn it off when we lock up and
go home. The engine battery switch gets turned on when I open the
engine seacock and off again when I close it. Apart from that, we never
need to touch the switches and even with a 12V peltier fridge, we never
have a flat engine battery. The whole setup is 'fit and forget'.

This topic has been done to death on uk.rec.waterways over the years
A search on google groups of that group with the phrase "split charging"
would be worth it for you.
--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & 32K emails -- NUL:
'Stingo' Albacore #1554 - 15' Early 60's, Uffa Fox designed,
All varnished hot moulded wooden racing dinghy.