Well now, what have we here? Prest-O-lite???
 

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!

Well now, what have we here? Prest-O-lite???
 

On 21 Nov 2006 18:31:16 -0800, "Tim" wrote:

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!

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

Well now, what have we here? Prest-O-lite???
 

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.


JohnH wrote:
On 21 Nov 2006 18:31:16 -0800, "Tim" wrote:

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!

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

Well now, what have we here? Prest-O-lite???
 

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.

Well now, what have we here? Prest-O-lite???
 

Ian Malcolm wrote:


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.


Ian, you are absolutely right, and actually thats what I did. I was
thinking one way and typing another.

And I AM glad you called that to my attention.

And actually, I'm going to revam it some more.

you said, something like : Why don't you use a combiner(Isolater)?"

Actually, I'm going to make my own. A commercially bought isolator
(combiner) is actually

a three(for the most common) post device, which has "Alternator output"
on usually the center post, and "Bat.1" on another, and "Bat 2" on the
third. And this contains a couple heavy diodes to allow the alt to
charge simoaniously both battery banks, yet, leave the bateries
independant of each other. And that's a good idea.

The problem I have with the commercially made products, is that if one
diode diode goes out. Then the whole combiner, as you say, is bad, that
is, unless you wish to press the diode pac out of the finned aluminum
heat sink, and dig through the epoxy, and finally figure out that
you're fairly well wasting your time trying to repair the unit (that
is, unless it's made to be repaired), only to have to go buy another
one.

I have found that it's much easier to have two seperate heat sinks and
configure them to do the same thing as the commercially sold unit.

Reasoning is, that unlike the mounted commercial unit, which you
usually end up having to mount in some hard to get to place (like on a
small power boat), you can take your seperate heat sinks and mount them
anywhere you wish..tuck them in convenient places.

Also, if and when one goes bad, then thats the only one you need to
replace.

besides, I have a bountiful supply of these, just sitting around in the
junk.. LOL!

Thanks for your Input, Ian, I will check out the various threads.

Tim

Well now, what have we here? Prest-O-lite???
 

Tim wrote:

Ian Malcolm wrote:


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.



Ian, you are absolutely right, and actually thats what I did. I was
thinking one way and typing another.

And I AM glad you called that to my attention.

And actually, I'm going to revam it some more.

you said, something like : Why don't you use a combiner(Isolater)?"

Actually, I'm going to make my own. A commercially bought isolator
(combiner) is actually

a three(for the most common) post device, which has "Alternator output"
on usually the center post, and "Bat.1" on another, and "Bat 2" on the
third. And this contains a couple heavy diodes to allow the alt to
charge simoaniously both battery banks, yet, leave the bateries
independant of each other. And that's a good idea.

The problem I have with the commercially made products, is that if one
diode diode goes out. Then the whole combiner, as you say, is bad, that
is, unless you wish to press the diode pac out of the finned aluminum
heat sink, and dig through the epoxy, and finally figure out that
you're fairly well wasting your time trying to repair the unit (that
is, unless it's made to be repaired), only to have to go buy another
one.

I have found that it's much easier to have two seperate heat sinks and
configure them to do the same thing as the commercially sold unit.

Reasoning is, that unlike the mounted commercial unit, which you
usually end up having to mount in some hard to get to place (like on a
small power boat), you can take your seperate heat sinks and mount them
anywhere you wish..tuck them in convenient places.

Also, if and when one goes bad, then thats the only one you need to
replace.

besides, I have a bountiful supply of these, just sitting around in the
junk.. LOL!

Thanks for your Input, Ian, I will check out the various threads.

Tim

The three terminal diode devices are definately isolators, but I
wouldn't call that a combiner.

A combiner consists of a heavy duty relay or contactor suitable for
continuous operation that parallels the batteries only when the
alternator is charging the batteries.

Commercial products usually sense the alternator output voltage, but
many DIY ones either sense the alternator warning lamp (like mine does)
or run off an oil pressure switch possibly with a disabling relay from
the starter solenoid coil terminals to prevent them engaging while
cranking. The advantage is no diode drops so you dont need to modify
the alternator to boost the output voltage or fit an external battery
sensed regulator to get a full charge on both batteries. It operates
just like a manual battery switch except you never need to remember to
switch it.

http://www.tb-training.co.uk/MarineE09.html#Split%20Charge%20Relay

is worth a look.

If you are interested in fitting something like that, I can dig out
details of the single transistor circuit I used to buffer the signal
from the warning lamp. Its really simple, just a couple of resistors
and diodes (to protect against transients) and the transistor mounted on
a piece of tagstrip or you could just fit a higher wattage warning bulb
as suggested in the link.

Alternatively, since you are in the trade, why not get a caravan or
motor-home split charge relay and beef it up by using its output to
switch a heavy duty relay or contactor (my original plan before I came
accross the discussion on uk.rec.waterways and learned I could save
about £15 by building my own simple controller)

Next year the plan is to extend it with another relay so the fridge and
various chargers for handheld gadgets get switched on automatically
whenever the engine is running and switched off when we are on the hook
unless I override it. Hot bacon sandwiches in the morning and a cold
beer in the evening are glorious to have and both need the fridge to be
run whenever possible . . .

--
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.

Well now, what have we here? Prest-O-lite???
 

Tim wrote:

you said, something like : Why don't you use a combiner(Isolater)?"

Actually, I'm going to make my own. A commercially bought isolator
(combiner) is actually

a three(for the most common) post device, which has "Alternator output"
on usually the center post, and "Bat.1" on another, and "Bat 2" on the
third. And this contains a couple heavy diodes to allow the alt to
charge simoaniously both battery banks, yet, leave the bateries
independant of each other. And that's a good idea.

The problem I have with the commercially made products, is that if one
diode diode goes out. Then the whole combiner, as you say, is bad, that
is, unless you wish to press the diode pac out of the finned aluminum
heat sink, and dig through the epoxy, and finally figure out that
you're fairly well wasting your time trying to repair the unit (that
is, unless it's made to be repaired), only to have to go buy another
one.

Tim

I have already covered what I would do and reccomend in my other reply
but I thought you would appreciate that my opinion of the commercial
diode isolators is no higher than your own.

For the price they are they ought to have heavy 24 carat gold plated
terminals and a gold plated pure copper heatsink not just some cheap
alternator diodes pressed into a P.O.S. turn to white powder in a season
aluminium heatsink.

Our yacht had a P.O.S. LUCAS isolator in a can and the previous owner
had been going through batteries like they wern't rechargable.
Fortunately the yard had just put a new set on and had had them on
charge while the boat was laie up.

When I took the isolator off the bulkhead to tidy up the wiring and
clean up and paint the rusty bracket, I found the aluminium can had
corroded right through and the transformer oil it relied on for cooling
had leaked out. It would have been fine if it had had a strip of
plastic tape round it from new seperating the two different metals.
The diodes were pretty well cooked, one was hard shorted and the others
were high resistance which meant one battery was getting less than an
amp of charging current :-( I was inspired to chuck it in the nearest
bin. Not what you want to find just before your first trip 'going foreign'.

You might appreciate this Lucas humour if you haven't seen it befo
http://www.mez.co.uk/lucas.html

--
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.

Well now, what have we here? Prest-O-lite???
 

Ok, Ian, I now know what you mean by a "combiner" Honestly I thought
that was a UK term for "Isolator pac" or of the sorts.
Ian Malcolm wrote:
Tim wrote:

Ian Malcolm wrote:


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.



Ian, you are absolutely right, and actually thats what I did. I was
thinking one way and typing another.

And I AM glad you called that to my attention.

And actually, I'm going to revam it some more.

you said, something like : Why don't you use a combiner(Isolater)?"

Actually, I'm going to make my own. A commercially bought isolator
(combiner) is actually

a three(for the most common) post device, which has "Alternator output"
on usually the center post, and "Bat.1" on another, and "Bat 2" on the
third. And this contains a couple heavy diodes to allow the alt to
charge simoaniously both battery banks, yet, leave the bateries
independant of each other. And that's a good idea.

The problem I have with the commercially made products, is that if one
diode diode goes out. Then the whole combiner, as you say, is bad, that
is, unless you wish to press the diode pac out of the finned aluminum
heat sink, and dig through the epoxy, and finally figure out that
you're fairly well wasting your time trying to repair the unit (that
is, unless it's made to be repaired), only to have to go buy another
one.

I have found that it's much easier to have two seperate heat sinks and
configure them to do the same thing as the commercially sold unit.

Reasoning is, that unlike the mounted commercial unit, which you
usually end up having to mount in some hard to get to place (like on a
small power boat), you can take your seperate heat sinks and mount them
anywhere you wish..tuck them in convenient places.

Also, if and when one goes bad, then thats the only one you need to
replace.

besides, I have a bountiful supply of these, just sitting around in the
junk.. LOL!

Thanks for your Input, Ian, I will check out the various threads.

Tim

The three terminal diode devices are definately isolators, but I
wouldn't call that a combiner.

A combiner consists of a heavy duty relay or contactor suitable for
continuous operation that parallels the batteries only when the
alternator is charging the batteries.


Ok, Ian, I now know what you mean by a "combiner" Honestly I thought
that was a UK term for "Isolator pac" or of the sorts.

What you would call a "combiner" is what I call a continous parallel
solonoid.

Commercial products usually sense the alternator output voltage, but
many DIY ones either sense the alternator warning lamp (like mine does)
or run off an oil pressure switch possibly with a disabling relay from
the starter solenoid coil terminals to prevent them engaging while
cranking. The advantage is no diode drops so you dont need to modify
the alternator to boost the output voltage or fit an external battery
sensed regulator to get a full charge on both batteries. It operates
just like a manual battery switch except you never need to remember to
switch it.

http://www.tb-training.co.uk/MarineE09.html#Split%20Charge%20Relay

is worth a look.

If you are interested in fitting something like that, I can dig out
details of the single transistor circuit I used to buffer the signal
from the warning lamp. Its really simple, just a couple of resistors
and diodes (to protect against transients) and the transistor mounted on
a piece of tagstrip or you could just fit a higher wattage warning bulb
as suggested in the link.

Alternatively, since you are in the trade, why not get a caravan or
motor-home split charge relay and beef it up by using its output to
switch a heavy duty relay or contactor (my original plan before I came
accross the discussion on uk.rec.waterways and learned I could save
about £15 by building my own simple controller)


Next year the plan is to extend it with another relay so the fridge and
various chargers for handheld gadgets get switched on automatically
whenever the engine is running and switched off when we are on the hook
unless I override it. Hot bacon sandwiches in the morning and a cold
beer in the evening are glorious to have and both need the fridge to be
run whenever possible . . .

LOL, Yes, I could do that, and that type of system you are describing
works rather well. I have seen it ( or varients of) on commercial
applications. Yes, i could do that, and I am privy to the products, but
in my case, I really do believe that to be quite a bit of overkill for
my purposes. seeing I dont' run a refrigerator, nor a stove.

Hot bacon sandwiches in the morning and a cold
beer in the evening are glorious to have and both need the fridge to be
run whenever possible . . ."

Agreed!


Ian, seeing you are thinking in these lines, if you ever wanted to
increase the power options on your boat and can use your imagination
some.

You can run 12 AND 24 v systems directly off your single 12v alternator
with some not-so-difficult modifications. like, adding a typical Delco
10-SI rectifier, and a transformer (which I cant think of its
electrical values at the moment...but can find out!).

you can have 12v "run, and 24v "options" in one neat little package.

GM has used Delco 30SI units with this modification, in heavy truck and
off-road applications. It eliminates the series/parallel switchs,
relays, and a whole bunch of wires.(not to mention, headaches.)

Well now, what have we here? Prest-O-lite???
 

Ian Malcolm wrote:
You might appreciate this Lucas humour if you haven't seen it befo
http://www.mez.co.uk/lucas.html



HAHAHAHAHA!

That is a riot!

I had heard a lot of those, but the "Smoke recharger" was the kicker.

The "Prince of Darkness" has been around a long time,

But, unless I missed it, I never saw on the site:

Joseph Lucas-- "The Black [K]night!"

Well now, what have we here? Prest-O-lite???
 

Tim wrote:
Ian Malcolm wrote:

You might appreciate this Lucas humour if you haven't seen it befo
http://www.mez.co.uk/lucas.html

HAHAHAHAHA!

That is a riot!

I had heard a lot of those, but the "Smoke recharger" was the kicker.

The "Prince of Darkness" has been around a long time,

But, unless I missed it, I never saw on the site:

Joseph Lucas-- "The Black [K]night!"

Glad you liked it, there are a few others that aren't there but it seems
to be a fairly comprehensive collection. The sad thing is though, we'd
rush to buy genuine Lucas electrical fittings if we had an alternative
to the pile of far east cr@p on offer in most chandlers. It couldn't be
less reliable . . . could it? . . .

--
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.