dual electrical system

groundhogyh · Jul 7, 2013

Hi Douglas,
I had the same spagetti problem. lol.
It was on my to-do list for a long time to clean up that electrical compartment, but I never did anything til my MD6A croaked last winter. I had to put in a new motor and therefore also the electrics.

I ended up with more than a grocery bag full of dead wires. Wires that go no where. People do modifications, and are not sure what a wire is for so they just put tape on it and tuck it away.

Anyway, I finally pulled out my multi meter, got a pencil n paper and went through every stinking connection, drawing out the schematic of what I had.

Then i sat and looked at it and tried to make sense of the scheme. And I looked. and looked.
It was trying to be two separate circuits, but then it wasnt. They were still connected.

On my MD6A, it had become such that the dynastart was only used as a starter, and the alternator was generating electricity. I have two batteries and one of those 1-2-Both-Off switches.

The new engine just has an alternator.

I just ended up wiring them both identically. Neither is house neither is only starter. They are both starter/house when selected. The other battery is resting and charging from my solar panel.

The wiring is simple and understandable for me.

groundhog

Sent from my iPad

lewills30 · Jul 7, 2013

Ijust finished pulling all the wiring mess out of the boat and pitched it in the trash. What a mess, wires going no where and a mass of wiring cut, taped and who knows to what. I am starting fresh and thinking one battery for just the engine duties and one battery for the house. I am thinking of glassing in the bulkheads, and adding additional sump pumps just in case I have a really bad day. I was going to put all life and safety on an additional battery. This would give me 3 batteries which can be located in the hull at different points to help keep things balanced. I am thinking a breaker panel for the engine, a panel for the house and one for life and safety. I am not feeling all warm and fussy with everything on one battery or one common panel . As I read through different articles and look into new boat designs , I keep coming across the term Back systems, or double back up. It makes a lot of sense to leave a way out of a pickle.

Larry Wills

V-2761
Sent from Windows Mail
From: groundhog
Sent: ?Sunday?, ?July? ?7?, ?2013 ?11?:?32? ?AM
To: AlbinVega@yahoogroups.com

Hi Douglas,
I had the same spagetti problem. lol.
It was on my to-do list for a long time to clean up that electrical compartment, but I never did anything til my MD6A croaked last winter. I had to put in a new motor and therefore also the electrics.

I ended up with more than a grocery bag full of dead wires. Wires that go no where. People do modifications, and are not sure what a wire is for so they just put tape on it and tuck it away.

Anyway, I finally pulled out my multi meter, got a pencil n paper and went through every stinking connection, drawing out the schematic of what I had.

Then i sat and looked at it and tried to make sense of the scheme. And I looked. and looked.
It was trying to be two separate circuits, but then it wasnt. They were still connected.

On my MD6A, it had become such that the dynastart was only used as a starter, and the alternator was generating electricity. I have two batteries and one of those 1-2-Both-Off switches.

The new engine just has an alternator.

I just ended up wiring them both identically. Neither is house neither is only starter. They are both starter/house when selected. The other battery is resting and charging from my solar panel.

The wiring is simple and understandable for me.

groundhog

Sent from my iPad

lewills30 · Jul 7, 2013

Hi Doug, I am wondering if you just keep the generator for the engine operations only , no wring or demands being used except for the engine off the generator. And run the house off the alternator, totally separate from the engine generator. A stand alone alternator system to the house, would this not eliminate any possible cross over use of the two systems? I am thinking in these terms for my own wiring mess, I would think if a electrical problem did arise, trouble shooting would be a little easier? I see a battery for each system and the solar panels and wind generator could be ran to a single point of contact and then passed on to the batteries for recharging? I think this would be a true dual electrical system, a lot safer then what I just pulled out here.

Larry Wills V-2761
Sent from Windows Mail
From: Douglas Pollard
Sent: ?Sunday?, ?July? ?7?, ?2013 ?9?:?22? ?AM
To: AlbinVega@yahoogroups.com

I guess in Vegas early years there may have only been one battery.
Then they added an Alternator for a house battery. So at that point
there was dual dialectical systems. You had to have a starting battery
and a house battery. You had the starter generator charging the
starting battery and the alternator charging the houses battery. You
can't cross these up in any way because the generator will burn out the
diodes in the Alternator or maybe the voltage regulator. I concidered
hooking all my batteries together to form one bank reasoning that if I
ran them all down dead I could just crank the engine. That can be done
but the generator has to be disconnected to let only the alternator
operate so that both don't output to a single battery bank. This works
fine on other boats with other engines.
The systems on my boat have been changed and the engine wiring looks
like spegetti has been thrown in there. I need to fix this mess. I
think Albin had the two systems pretty well worked out. My boat had the
batteries moved to the starboard cockpit locker. There were two master
switches installed one for the starting battery and one for the house
batteries. The original Albin wireing system was bypassed and a switch
panel installed. This was likely a good thing as we likely put more
demand on the house wireing than was originally intended and the
insulation is old now so is likely dangerouse.
I am not sure the 6 amps out put by the generator justifies two
complete electrical systems any longer. An advantage would be that any
kind of 12 volt selinoid engage the starter and no other electricals
would be needed for the generator.
Power for the house system could be taken directly through the
battery switch directly from the batteries. Power for engine would come
through the starting main switch then going through the ignition switch.
This May not work as they both have to be on so as to not burn out the
alternator diode. ( In case anyone is wondering I am just thinking out
loud with this post. ) The two switches on the starting system may not
be a good idea if there is no separate charging starting battery.
Because it is so easy to be at the dock and start the engine with
a battery charger on it is easy to burn up the alternator circuit. My
first inclination was to never charge the starting battery with a
battery charger and use only the starter generator to charge it thus
eliminate the possibility of running the engine with a charger on. I
guess a solution would be to have the ignition switch automatic shut off
the battery charger. This was using the two seperate systems as designed.
After all this thinking what I think I will do is start over. I
will disconnect all the engine wireing. Then hook up the starer/
generator and its sellinoid as was oriinally done with power coming
through ignition switch. If this works and charges I will know the
selinoid is OK. Then I will hook up the alternator so that I can check
it's output and that it is charging batteries. I will have to be sure
that the generator and alternator cannot both charge both battery sets
so as to inter-fear with each other. I guess if I want to charge the
starting battery I will have to be sure the starting battery main switch
is turned off so the engine cannot be started. Be nice if it had a
lockout on it for safty sake. Still the same is true of the house
battery. I would like this all to be fail-safe. I am thinking that the
alternator has to have exciter current to operator so if that is not
turned on it can't try to put out current and burn out it's diaode.
I du id not intend to post this but then somebody may have a a good
solution to this or just maybe learn something from the execise. I have
learned a few things and hope it helps someone else.
I think I will go to a single charging system using only the
alternator as that is likely the last complicated and so maybe the most
dependable.
In any case input would surely be welcome as I am likely in over my
head.

Doug

tiempo2010 · Jul 8, 2013

Doug

I agree, lose the generator. Run the alternator output directly to the
positive post of the house bank. This is where it is needed most, start
battery is seldom down more than 1/4 AH or so from an engine start. Buy an
Echo Charge and wire it between the house and start batteries. It will
automatically keep the start battery charged - it is a battery to battery
charge device and very reliable. Keep the 2 separate switches for house and
start banks. Make sure that only engine start and engine panel power is
drawn from the start battery. House feeds everything else. Fuse both
battery banks close to the positive post with ANL fuses. This is the way
many sysyems are wired today. I have done this on battery banks as small as
one group 24 battery and as large as 1000 AH.

groundhogyh · Jul 9, 2013

Hi Douglas,
Another way to charge both batteries is to have a small solar panel. You buy a charge controller as well. Wires go from panel to controller, controller to batteries.

I have a Morningstar brand controller that is made to charge 2 banks. It feeds whichever bank needs it more.

Advantage here is, you don't have to run the motor for charging. And if you are away from the boat for long periods, the batteries are still happy.

groundhog

Sent from my iPad

btfag0s · Jul 9, 2013

Am I in the minority here?
I have two batteries, one alternator, a wind generator, and a
1-2-both-off switch.
- the alternator is the input to the switch so I decide where the
power goes, and which battery is used for starting, lights etc. -
when away from the boat the switch is in the off position, however
the wind generator output bypasses the switch so is always connected
to the batteries although they remain isolated by the wind generator's
regulator. - when I'm away from the boat the wind generator charges
the batteries, with any excess going through a large dump resistor.
(I sail in a part of the world where wind power makes more sense - in
other latitudes, and with more deck space, I would probably use
solar.) - I also have a connection from one battery to a float
switch and a bilge pump that bypasses the switch.
Net result is that both batteries are usually fully charged and the
boat is dry. If there's water ingress then the bilge pump should clear
it; if the switch sticks then the worst case is that one battery will
be dead and the other one will be unaffected.

I don't like the idea of running two generators off an engine; you
still have no generating capacity if there's an engine problem, and
there's extra load on the engine (I long ago dumped my Albin
petrol/gas engine with dynastart, and can understand if you've added
an alternator to that setup).

Alisdair

dougpol1 · Jul 9, 2013

In my case the Volvo engine origanally came with a starter generator and an alternator and has remained that way. So the boat efectivly has two electrical systems. At the present time I don't really know for sure what I have. As the wiring is such a mess I am think I need to start over. I have decided not to use the generator at all. I will charge all batteries with the 35 amp alternator. As Brent suggested I will have a starting battery seperated from the house batteries with master switch's. I have a quest 10 volt two lead battery charger that can charge house and Starter battery seperately at the same time. I am concerned that someone will start the engine at the dock with the battery charger running and this will kill the diode in the Alternator or maybe the Voltage regulator instantly. I am waiting for information from quest as to whether or not the charger will shut down if the alternator puts out voltage. I fellow I talked to their said it would and after questioning him further he wasn't sure. I think I will need a diferent solution for that but am waiting to hear. This may be one of those things that I will have to be careful of. DougOn Tue, 09 Jul 2013 15:52:33 +0100
yahoo@... wrote:

tiempo2010 · Jul 10, 2013

Doug

You can start the engine with any charger turned on. Myself and my
neighbors do it regularly. Same as if you have solar or a wind gen.

dougpol1 · Jul 10, 2013

Brian you are absolutly right. How I got started thinking that the battery charger would ruin the voltage reulator or the alternator diods I don't know. Maybe it cam from setting here in front of the computer an trying to think through this thing. It may have come from hand cranking the engine to start it. IF you start the engine with the ignition switch not turned on it will ruin the voltage regulator. Anyway I now have a diagram drawn up using only the alternator to charge batteries. I will have a starting battery and two house batteries. I used to use an isolator on battery banks like this. My present arangement does not have one. To be honest I can't even remember what an isolator does. I guess I could get out my 12volt doctor book but it's 200 miles away on my boat. If you can help with the isolator info it will let me make that decision befor I go to work on the boats electricals. DougOn Wed, 10 Jul 2013 05:26:54 -0700
Brian Stannard brianstannard@... wrote:

dougpol1 · Jul 10, 2013

I am on the horns of a delema with this. I have a set of running lights at the top of the mast with a steaming light part way up and then a stern light, In addition I have another set of running lights on the bow at deck level. These are turned on at an electrical panel in the cabin. The steaming light and mast head lights are controlled with separate switches on the engine panel in the cockpit. So this has to be sorted out. The engine panel operated lights may work off the starting battery or the house battery I don't know which. I may rig them all to cabin electrical panel to operate all lights and do away with the switches on the engine panel. I likely would use the mast head lights when at sea where the height would make me more visible to ships. I am guessing the engine panel lights only run off the starting battery?? I have been making drawings and have so far come up with three different ones to accommodate all these lights and electrical systems. I am favouring running everything off the electrical panel inside the cabin where every light will be fused and not using the generator at all. The generator as a back up system is tempting but that is another whole story as it does have to be hooked up to a Battery but does not output enough to operate running lights so I am not sure of it's value. Doug
On Mon, 8 Jul 2013 06:31:14 +0000
lewills30@... wrote:

tiempo2010 · Jul 10, 2013

Doug

There is a voltage drop with battery isolators so they are seldom used now.
unless you have an external regulator for the alt that has voltage sensing
at the battery. ACR's, Echo Charge, and Duo Charge are the methods used
now. I favor the Echo Charge for a house bank plus starting battery. It is
fully automatic and trouble free. All charging goes direct to the house
bank and the Echo Charge takes care of the start battery. As long as the
alt output goes to a battery directly and not through a switch that can be
accidently turned off there is no problem starting the engine.

tiempo2010 · Jul 10, 2013

The gen has little value Doug. I would eliminate it. as far as the nav
lights they should all run off the panel inside. The start battery should
only be used for engine starting and engine related items like fuel pump if
electric and the engine panel of course.

n4lbl · Jul 10, 2013

I've been away and neglected keeping up with you guys. I'm going to fire
away and hope that I'm not making things worse.

You can't get rid of the generator because it is also the electric starter
(conveniently ignoring the hand starter!). IIRC it is called something
like the "Dyna-Start". As a generator it is rated at 90 watts continuous
(135 peak) so at the right speed and load it could deliver ~7.5 amps
continuous. So,,, if your starter (generator) is connected to your starter
battery your generator is too. NOTE: I am referring to the Volvo MD6A.
Other engines may be different.

I found an interesting discussion of the Xantrex Echo Charger at

Xantrex Echo Charger Rant

Hi All, For nearly six years I have been conversing with Xantrex and asking them to make important changes to the Echo Charger manual. Quite often I have had to spend time trouble shooting a device that is working properly but because the owners manual is INCORRECT, POORLY WRITTEN, MISLEADING...

www.sailnet.com

.Back to the dual system issue. If we had an Echo Charger charging the
starter battery AND had the starter generator charging the starter battery
I can see no harm. No, I don't actually know that that is OK and I hope
someone either explains why I am wrong or right.

My previous owner told me to not switch the battery switch (off, 1, 2,
both) at all with the engine running as it would blow the diodes in the
alternator. It is my belief (again, I'm looking to be corrected) that all
those battery switches are make-before-break so any switch position is OK
when running except off and you can switch between 1 & 2 & both at will.

Alan

marcin_palacz · Jul 10, 2013

On 10/07/13 19:55, Brian Stannard wrote:

dougpol1 · Jul 10, 2013

Well Marcin, the way I am seeing it is, the generator is only putting out about 6 amps. If the Alternator fails the little generator won't keep the batteries up anyway. Yes the generator and starter are one in the same but if the generator is not hooked to anything it won't be putting any load on the engine. Most of the time I start up the engine run maybe a 1/4 mile and start sailing. That is not likely time enough to put back into the battery what starting the engine took out. Anyway as for now I haven't made a decision yet. I am however going to change both sets of running lights to operate off the house batteries through the switch panel and its fuses. I also will have everything in the house circuit come through the main switch and directly from the house batteries. The only thing that will be on the starting battery will be the starter and the instrument panel. This will let all engine lights come on. This is what I have in mind right now. I think this will be the least complicated I still have a few days to think about it before getting started so we will see. I plan to start by hooking up everything to the house battery and when complete and working I will see about the generator. I'll see how it goes. Thanks everyone for all the input. Now I have to decide something Doug

On Wed, 10 Jul 2013 21:06:34 +0200
Marcin Palacz palacz@... wrote:

tiempo2010 · Jul 11, 2013

Doug

I read the post you linked to when it was posted - I posted on that thread
as well. They are discussing minor details but Maine, Bill Trayfors (the
first 2 posters) and others agree it is a good product that does a great
job of keeping a start/auxiliary battery charged. Nothing has changed, I
installed one in a Catalina 30 last week where it worked as advertised.

You should keep the Dynastart generator as it is your starter, removing it
would be expensive as a starter would have to be added. There is nothing
wrong with 2 sources on the same battery - eg the generator as well as the
Echo Charge. No different than running an engine with solar or a wind gen
also charging batteries.

The switches that you were told never to switch to off when the engine is
running are not a factor as the charge from the alternator is fed directly
to the house battery bank. They are only an issue if charging is routed
through them to the batteries.

tiempo2010 · Jul 11, 2013

Multiple source charging, as from an alternator and generator at the same
time, is not a problem. Add solar, wind gen, and even a shore charger into
the mix and there are no issues either.

dougpol1 · Jul 12, 2013

Ok Brian what you are saying basicly is (not that I would do this) that it would work to hook Alternator and generator both to the same battery. I thought this would burn out the diode in the alternator?? This being true I have no problem except for having a birds nest of wiring that needs to be redone. DougOn Thu, 11 Jul 2013 19:47:56 -0700
Brian Stannard brianstannard@... wrote:

tiempo2010 · Jul 12, 2013

It is not a problem Doug. There are many instances where a twin engine
powerboat runs both alt outputs to a single large battery bank. In bulk
charge it is the sum of both outputs. When one of the 2 reaches the its set
point (ie the battery bank reaches the proper voltage) the output of both
will slow but by then the batteries are accepting less current anyway.