-One alternator lead to house batteries (two 6 volts wired in series)

-One alternator lead to starting battery

-One shore power charger lead to house battery

-One shore power charger lead to starter battery

-Starter battery to bank one switch lead

-House battery to bank two switch lead


Seems there is a better way to do this but now that I'm finally putting
it together I don't remember what the better way is! Do I have it right?
Help!

Thanks,

Stephen

Stephen Trapani wrote in news:Ezski.5$bu6.0
@newsfe12.lga:

-One alternator lead to house batteries (two 6 volts wired in series)

-One alternator lead to starting battery

-One shore power charger lead to house battery

-One shore power charger lead to starter battery

-Starter battery to bank one switch lead

-House battery to bank two switch lead


Seems there is a better way to do this but now that I'm finally putting
it together I don't remember what the better way is! Do I have it
right?
Help!

Thanks,

Stephen


How many alternators do you have, one or two?? If you have just one, and
there are two wires leading from the alternator output to the two
batteries, you have just connected them in parallel. If this is the
case, when you crank the starter, the house battery current backs up
through that alternator wire, which is probably NOT rated for a couple of
hundred possible amps, creating quite a fire hazard when the starter
melts the wires! If you have two alternators, this is fine.

The same goes for the charger. If you have just a single output charger
with both + wires going to the two batteries, that, also, parallels the
battery banks, creating a similar fire hazard.

Now, if the alternator or charger cables are hooked straight to these two
batteries, they effectively bypass the battery switch, rendering it
useless to separate the two batteries. There is no "off".

If you have a single alternator and single output charger and have BOTH
of them connected to the COMMON terminal of the big battery switch...not
the batteries or starter cable directly...that'll work fine. Just set
the switch to BOTH and either charger will charge BOTH just fine in
parallel, which is what BOTH does, anyways.

We have to know more DETAILED information about your setup to figure out
what you have connected. Use the | - + _ / characters and draw us a
little schematic of it.



Larry
--
While in Mexico, I didn't have to press 1 for Spanish.
While in Iran, I didn't have to press 1 for Farsi, either.
It just isn't fair.

Larry wrote:
Stephen Trapani wrote in news:Ezski.5$bu6.0
@newsfe12.lga:

-One alternator lead to house batteries (two 6 volts wired in series)

-One alternator lead to starting battery

-One shore power charger lead to house battery

-One shore power charger lead to starter battery

-Starter battery to bank one switch lead

-House battery to bank two switch lead


Seems there is a better way to do this but now that I'm finally putting
it together I don't remember what the better way is! Do I have it
right?
Help!

Thanks,

Stephen


How many alternators do you have, one or two??

One. And one AC charger. Fortunately I haven't hooked up the starting
battery yet.

If you have just one, and
there are two wires leading from the alternator output to the two
batteries, you have just connected them in parallel. If this is the
case, when you crank the starter, the house battery current backs up
through that alternator wire, which is probably NOT rated for a couple of
hundred possible amps, creating quite a fire hazard when the starter
melts the wires! If you have two alternators, this is fine.

The same goes for the charger. If you have just a single output charger
with both + wires going to the two batteries, that, also, parallels the
battery banks, creating a similar fire hazard.

Now, if the alternator or charger cables are hooked straight to these two
batteries, they effectively bypass the battery switch, rendering it
useless to separate the two batteries. There is no "off".

If you have a single alternator and single output charger and have BOTH
of them connected to the COMMON terminal of the big battery switch...not
the batteries or starter cable directly...that'll work fine. Just set
the switch to BOTH and either charger will charge BOTH just fine in
parallel, which is what BOTH does, anyways.

So I hook the alternator and AC charger to the common terminal of the
big battery switch, ditch the extra wire the PO had coming off of each,
and I have terminal 1 on the big battery switch go to the starter
battery and 2 terminal go to the house battery. Is that right?

The DC panel is also hooked to the common terminal.

We have to know more DETAILED information about your setup to figure out
what you have connected. Use the | - + _ / characters and draw us a
little schematic of it.

Sahly! No speaka elec-tahnics! :-(

If you need more info with a diagram show me how to do it and I will.

Thanks a million Larry!!

Stephen

"Stephen Trapani" wrote in message
...
Larry wrote:
Stephen Trapani wrote in news:Ezski.5$bu6.0
@newsfe12.lga:

-One alternator lead to house batteries (two 6 volts wired in series)

-One alternator lead to starting battery

-One shore power charger lead to house battery

-One shore power charger lead to starter battery

-Starter battery to bank one switch lead

-House battery to bank two switch lead


Seems there is a better way to do this but now that I'm finally putting
it together I don't remember what the better way is! Do I have it
right?
Help!

Thanks,

Stephen


How many alternators do you have, one or two??

One. And one AC charger. Fortunately I haven't hooked up the starting
battery yet.

If you have just one, and
there are two wires leading from the alternator output to the two
batteries, you have just connected them in parallel. If this is the
case, when you crank the starter, the house battery current backs up
through that alternator wire, which is probably NOT rated for a couple of
hundred possible amps, creating quite a fire hazard when the starter
melts the wires! If you have two alternators, this is fine.

The same goes for the charger. If you have just a single output charger
with both + wires going to the two batteries, that, also, parallels the
battery banks, creating a similar fire hazard.

Now, if the alternator or charger cables are hooked straight to these two
batteries, they effectively bypass the battery switch, rendering it
useless to separate the two batteries. There is no "off".

If you have a single alternator and single output charger and have BOTH
of them connected to the COMMON terminal of the big battery switch...not
the batteries or starter cable directly...that'll work fine. Just set
the switch to BOTH and either charger will charge BOTH just fine in
parallel, which is what BOTH does, anyways.

So I hook the alternator and AC charger to the common terminal of the big
battery switch, ditch the extra wire the PO had coming off of each, and I
have terminal 1 on the big battery switch go to the starter battery and 2
terminal go to the house battery. Is that right?

The DC panel is also hooked to the common terminal.

We have to know more DETAILED information about your setup to figure out
what you have connected. Use the | - + _ / characters and draw us a
little schematic of it.

Sahly! No speaka elec-tahnics! :-(

If you need more info with a diagram show me how to do it and I will.

Thanks a million Larry!!

Stephen


Here's a schematic of sorts that came with a product I purchased for my
system. I have two batt banks (start and house), one batt charger, one batt
switch, one alternator, and now one combiner/isolator.

https://resources.myeporia.com/compa...atteryLink.pdf


--
"j" ganz @@
www.sailnow.com

Stephen Trapani wrote:

Sahly! No speaka elec-tahnics! :-(


If you can not produce a schematic of what you are doing and interpret one,
you have no, that's ZERO, ZIP, NADA, ABSOLUTELY NO, business fiddling with
this stuff yourself. It isn't rocket science and you should be able to
figure out what to do from some books and web research but it involves being
able to draw it out on a piece of paper and figure out what it is doing.

Get some professional help. It will be expensive but so are fires and
cleaning acid from exploded batteries out of your boat. Passenger lawsuits
are even more expensive.

--
Roger Long

Roger Long wrote:
Stephen Trapani wrote:

Sahly! No speaka elec-tahnics! :-(


If you can not produce a schematic of what you are doing and interpret
one, you have no, that's ZERO, ZIP, NADA, ABSOLUTELY NO, business
fiddling with this stuff yourself. It isn't rocket science and you
should be able to figure out what to do from some books and web research
but it involves being able to draw it out on a piece of paper and figure
out what it is doing.

It's not that I can't produce a schematic, it's that I don't know how to
do it with the pluses and minuses on this keyboard like Larry asked. Can
you show me what he meant?

Get some professional help. It will be expensive but so are fires and
cleaning acid from exploded batteries out of your boat. Passenger
lawsuits are even more expensive.

I know a fair amount about electronics. Plus I have a diesel gmechanic
helping me, but he doesn't know much about boats.

Stephen

It's a lot of work to produce a schematic that way. Scanners and digital
cameras are so common now that posting a jpg of hand sketch would be much
easier and clearer but newsgroup rules prohibit posting of images. If you
have a web site or friend with one, you could upload the image to the server
and post the link here as I do often.

You need better, or clearer, advice than you'll get here though. Try and
find a mechanic who knows boat systems.

I would recommend a dual output battery charger. It will make everything
much simpler.

--
Roger Long

* Stephen Trapani wrote, On 7/9/2007 3:53 PM:
If you need more info with a diagram show me how to do it and I will.

Thanks a million Larry!!

Stephen

The problem of course with the traditional setup is that if you leave
the switch in "Both" you can kill both batteries. And, if the switch
isn't wired with an alternator shutoff, a mistake can kill the diodes.

A better solution is to use some method that automatically combines
when charging, and disconnects otherwise. There are several combiners
that are based on relays that do this. I use a slightly different
technique, an EchoCharge, that gives the stating bats a nice charging
current whenever the main bank is charged from any source.

Stephen Trapani wrote in news:snwki.452
:

So I hook the alternator and AC charger to the common terminal of the
big battery switch, ditch the extra wire the PO had coming off of each,
and I have terminal 1 on the big battery switch go to the starter
battery and 2 terminal go to the house battery. Is that right?



There is a problem hooking it up this way. If you EVER screw up and plug
in the charger with that switch in the OFF position, the full open
circuit voltage of the battery charger, somewhere around 20-25 pulsating
VDC, will be applied to everything connected to the COMMON side of the
switch....without the battery regulating the maximum voltage of it. This
will blow every electronic gadget hooked to it on a live circuit....EVEN
IF IT IS NOT TURNED ON! Electronic gadgets use electronic switching, not
real power switches, those push button on gadgets. It will destroy them

So, I don't advocate doing it. I advocate using an isolator for both.
The diode isolators are fine. Connect the alternator to one and the
charger to another...SEPARATELY... There are 3 terminals....BATTERY 1,
BATTERY 2, SOURCE (the alternator on one and the charger on the other).
This will CHARGE both batteries from whatever charging source is running,
even both, WITHOUT inadvertently parallelling the batteries because one
of the diodes will be reversed biased when one battery tries to load the
other when running on batteries.

The other way to do it is with continuous-duty 12VDC and 115VAC
contactors available from auto parts places more cheaply. These look
just like a starter relay, except they have coils made for continuous
duty (always on).

When I hook these up, I use a manual switch feeding 12VDC by the engine
controls for the alternator charging and a 115VAC contactor for the
single-ended battery charger that works automatically any time you plug
the boat charger in. The heavy current contacts of the 12VDC contactor
parallel the + of the starting battery with the + of the house batteries
and have large capacity short cables between the two battery banks so I
can parallel all batteries for starting, sort of like jumper cables, if
the starting battery fails and the house batteries aren't dead. It gives
the starter all the power I have for starting a recalcitrant engine.
Normally, I would leave the charging switch off, starting the engine on
the starting battery alone without loading it with the partially-dead
house batteries we used last night. As soon as the engine starts, I flip
the switch, closing the big contactor, parallelling the batteries on the
single alternator charging the lot of them. To prevent me from
forgetting to open the switch, inadvertently leaving the house wearing
out the starting battery all night, the 12V power for this manual
charging switch comes from the engine ON switch. Switch off the engine
and power is ALWAYS removed from the alternator's contactor, no matter
where the charging switch is, disconnecting the parallel circuit used for
alternator charging. Placing the manual charging switch right next to
the engine keyswitch reminds most, but not all, sailors to check the
switch when turning the engine on and off.

The normal procedure would be:
Charging switch off
Engine switch on
Crank engine
Charging switch to on for charging and running it all from alternator.

Shutdown is:
Charging switch off
Engine off
just to get you used to switching the charging to off for the next start.

When I plug into a dock, or crank the AC power plant if you have one, the
AC voltage automatically closes the AC contactor, parallelling the
battery banks for charging from the single output shore power charger.
Unplug the boat, the contactor opens the parallel circuit, automatically.
AC contactors are found at electrical wholesale stores. Be sure to get
one that is explosion proof in case there is a gas leak, even in a diesel
boat. Sealed contacts corrode much later than open contacts. Both
batteries will charge, without question, from the AC charger,
automatically placed in parallel for charging by this contactor any time
115VAC is applied to the boat/charger circuit. Get the power for the AC
contactor from the charger side of the charger's AC circuit breaker. If
you turn off the charger with the breaker...the battery contactor
separates the batteries, automatically. Simple and very effective.
Damned near "Captain Proof"!

All this is done SEPARATELY from the battery switches....directly to the
batteries, themselves. The contactors are right on the side of the
battery boxes to reduce cable length/resistance. Hooking it up
separately eliminates any possibility of the alternator or charger being
connected up to expensive electronics without a proper battery in the
circuit. You can charge from either source with both battery switches
OFF this way. It matters not where the battery switches are set.

Be sure to FUSE the batteries' primary circuits, too! WAY too many boats
have no circuit protection in the battery primary circuit! A shorted
starter makes a battery go BOOM! It doesn't have to be that way. I'm
using #2 cables with 250A fusible links available from West Marine. The
starter doesn't blow them....even if the engine is locked unless you hold
the starter on over a few seconds..

EACH Battery (-) through fusible link to common (ground).
115VAC CONTACTOR
|-------| |--------|
| |
STARTING+-----|-------| |--------|------------+HOUSE
12VDC CONTACTOR

+12V-----][-------][-----12VDC CONTACTOR COIL-----GND
ENGINE CHARGE
KEYSW SWITCH

115VAC (HOT)------][------115VAC CONTACTOR COIL---AC NEUTRAL
CHARGER
BREAKER

(Sure wish we could post pictures of SCHEMATICS!)

Because the interbattery contacts NEVER leave the load disconnected from
a battery, switching them hot charging never pulses anything. You see
the lights get brighter...(c; If you don't care that the house batteries
may also be used by the starter, just leave the CHARGE SWITCH on all the
time. The engine keyswitch always turns off the 12VDC contactor,
anyways.


Larry
--

Larry,

If you email me a jpg of a schematic, I'll put it on my sever and post a
link.

--
Roger Long