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C-Dory Factory Battery Wiring for Twin Engines

 
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PostPosted: Mon Oct 27, 2003 12:54 pm    Post subject: C-Dory Factory Battery Wiring for Twin Engines Reply with quote

From: Mike (Original Message) Sent: 4/6/2003 12:28 PM
Note: This discussion is copied from the C-Brat Pub. A lot of good info here, so I thought it should be saved in the library. All of the messages that say they are from Mike are copied.
From: PatA (Original Message) Sent: 3/27/2003 5:45 AM
Once again into the fray.
Most of you with twin engines have one engine's charging system connected directly to one battery and the other engine's charging system connected to the other battery. The C-Dory factory at some point decided they had a better idea, and connected both engines' charging systems to the battery switch, so when both engines are running, depending on the switch setting, it could be charging both batteries or either one separately. Don't know when this change occurred, but DavidA's Anna Leigh was definitely wired that way, and it sure looks to me like mine is too (Jim and Laurie - could you check Laurna Jo and let us know?).

According to one knowledgable source, this is a definite no-no, as it is clearly described in the Honda BF40/50 installation manual that each engine must be separately connected to its own battery. The problem is potential damage to the charging coils. The C-Dory factory contends that no damage will occur if you have the battery switch in the "both" position when both engines are running. I don't want to accidently damage the charging coils, though, if I switch to one battery to power the cabin at anchorage and forget to change it back to both when I start the engines in the morning. This potential problem is nowhere mentioned in the C-Dory Owners Manual. The knowledgable source also says that the C-Dory folks are wrong, that you can still damage the coils even if the battery switch is in the "both" position.

I am inclined to hang on until the 20 hours service (about 7 more hours), and then tell the factory that they need to wire the charging systems to the batteries separately, just like it says in the Honda installation manual. Thoughts?

From: Mike Sent: 4/6/2003 12:28 PM
From: Riverrat Sent: 3/27/2003 7:18 AM
Pat A

I definitely agree that the "both" contact could cause damage from the two alternators fighting each other. Either get them to take the switch out, or add a single switch to the other motor & battery, & use this one for your house/starting battery off one motor.

My factory wired twin 40 setup (2002) has each motor with its own battery & no switches at all. I'm adding a single position switch to port one, and a three position to starborad to permit adding deep cycle house battery (with isolator).

Riverrat (Lou B on Chinook)

From: Mike Sent: 4/6/2003 12:29 PM
From: Sealife5 Sent: 3/27/2003 9:34 AM
On Sealife, I have separate batteries for each engine controlled by separate 3 way switches. In this way I can use either battery to start either engine in case of a faluire of either battery. I can simply run my house by switching off my #2 battery. I also have a battery combiner that insures that a battery that becomes discharged does not drain charge from the other charged battery. I have a third battery stored under the front passenger seat that is isolated for use with my anchor windlass. The battery combiner assures that this battery is kept charged equally with the other two. In the unlikely event that both engine batteries fail, I have a cable with alligator clips that I can use to connect the windlass battery to start an engine.

Mike - Sealife

From: Mike Sent: 4/6/2003 12:29 PM
From: wilbe asea Sent: 3/30/2003 7:30 PM
When I checked the C-Dory website, it states that motor, batteries and trailer are supplied by the dealer (on the pricing page). My dealer supplied me with only one battery. Am I being taken advantage of here, Is it normal for a dealer to provide two batteries and switch? From the posts in this discussion so far it seems as if that is the case.

From: Mike Sent: 4/6/2003 12:32 PM
From: Blue~C Sent: 3/30/2003 7:41 PM
The rigging would be between you and the dealer. You should have a chat with your dealer about connecting two charging systems to one battery. There are some electrical components available that will allow one battery to be charged by two alternators but I bet they didn't install one because they cost more than a battery. Voltage spike backfeeding to a charging sytems spells electrical death to diodes = no more charging.......One battery for the twins to share is cheesey

From: Mike Sent: 4/6/2003 12:33 PM
From: TyBoo Sent: 3/30/2003 8:01 PM
It would seem to me that the minimum your rigger should have done is to install two batteries - one for each motor. If he wanted to go cheap, he could have skipped the switch. I asked a local Honda dealer last year about hooking the charging circuit from my kicker to the battery along with the main motor, and he said absolutely not. In fact, he said he had just got some service bulletin or something from Honda warning against it.

Good luck.

Mike

From: Mike Sent: 4/6/2003 12:45 PM
From: DavidA Sent: 4/1/2003 4:08 PM
Okay here is how I understand it from the "knowledgable source". From the factory the engines came wired to the BOTH position. This could burn out the coils in the engines if run this way long enough. My twin Hondas are now each separately wired to their own battery. The battery switch only controls the power to the rest of the boat, ie electronics, lights, etc. The engines are always charging their respective battery when running. There also is always power to the ignition switches from the respective battery even when the battery switch is in the OFF position. You should only run on either 1 or 2 battery and NEVER on BOTH position. When anchored or moored you should only use a single battery so you always have a fully charged battery to start the engine. And this is the only time you would use the BOTH position when you need to now start the "dead" battery engine and then immediately turn the switch back to the fully charged battery. This I am told is how Honda says they should be wired.

You could always install a separate switch between the engine and its battery if you really feel the need.

DavidA

From: Mike Sent: 4/6/2003 12:46 PM
From: LBL Sent: 4/4/2003 4:21 PM
Ok, this pertains to Honda engines:

With twin Hondas you *MUST* have one battery for each engine and they *MUST* never be paralleled (that is, using the "both" or "all" position on the battery switch or wiring them together) when both engines are running. In fact, it's also important that the wiring harnesses to the instruments were not "cross-pollenated" as that accomplishes the same thing as putting the switch in the both position. With regard to the motor's electrical systems, they must each remain an entirely separate entity. The 1-both-2-off switch is only used to determine which motor (or battery if the motors are shut down) is going to supply power to the boat's electrical system...and only one battery at a time with the engines shut down if you want some juice left to fire the engines with. Or, with one dead battery the 1-both-2-off switch can be used like a jumper cable to feed power to the dead battery; the motor connectd to the 'good' battery must *NOT* be running. The motor connected to the 'dead' battery is started with the switch in the 'both' position and then the switch is moved to the 'good' battery position and then that engine can be started.

Riverrat...you can *NOT* run a battery isolator on Honda outboards; you can run a battery combiner.

wilbe asea...with a single Honda you can have one or two batteries (or as many as you want) but it's best to just run on one at a time since there isn't a lot of charging capacity (16-amps). Again, you can *NOT* use a battery isolator. If you have twins and one battery (and they're Hondas) that isn't good at all (see above).

I'm not trying to be a "know-it-all" here; I'm trying to help keep folks from frying their charging coils and help you get the most out of your electrical systems.

From: Mike Sent: 4/6/2003 12:46 PM
From: Big Mac Sent: 4/4/2003 7:07 PM
Hello Les, Not being an electrical wiz how do I tell if I have a problem with my 2001 twin 40 HP Honda Cruiser. It has a battery switch as you described. I have the shore power with battery charger option. Is their a quick way to tell if I have any wiring problems with the batteries or instruments? It was wired by the Factory in July of 2001. I had never heard of starting one of the engines the way you described if one battery is dead. I did have one not start after an extended stay without shore power. I used my 1000 watt Honda generator with jumpers to start the engine. If it happens again I will try the (both) switch position. Any help will be apprecitated.
Happy Boating, Big Mac.

From: Mike Sent: 4/6/2003 12:46 PM
From: wilbe asea Sent: 4/5/2003 1:21 AM
LBL

Thank you for the information about the Honda wiring, now I really have a beef with the purveyor of this fine product, my C-Dory and its Hondas. Upon close inspection of the generator/starter wiring, I find both motors wired directly to the pos. and neg posts of the battery.

I will be following up on this issue with Ak. Mining and Diving, will post results as I get them.

Again, thank you for your knowledge and your willingness to share.

From: Mike Sent: 4/6/2003 12:47 PM
From: LBL Sent: 4/5/2003 6:15 PM
Big Mac - the battery charger doesn't factor into the wiring issue; at least, not with regard to how the main engine battery cables are dealt with. The instument wiring is a bit more complex and it would be difficult to describe it all here. Generally, if turning the key on one remote controller (or key switch) only activates one tach, teim meter, volt meter, hourmeter (or whatever you have) then you're probably fine. If you get the 'off' side instrument reacting to the switch-on key then things have been tied together. And, if all the instrument lights come on when either key switch is turned on you're cross-feeding there. It's ok if the instrument lights all come on with the nav light switch.

Put quite simply...the postivie battery cable coming out of each of the twin Honda engines must go directly (though a simple on/off switch is ok) to it's own battery. So just follow where the engine's battery cable heads off to and make sure that the positive cables [from both engines] are not tied together in any way. Typically the port engine's cable goes through a motorwell boot on the port side to a battery mounted to port and the starboard engine's cable goes through the starboard motorwell boot to the starboard battery. The positive terminals of each battery are then usually taken to a 1-both-2-off switch. All the ground cables are tied together and typically this would be with a cable running between the port and starboard batteries.

The boat's main 12-volt wire should come off the 'common' post on the back of the battery switch so that you can choose which motor (or battery if the engines aren't running) will supply power to the boat's electrical panel.

The thing to remember is to never have the battery switch in the 'both' position when both engines are running (no matter how that happens). You can use the 'both' position when only one engine is running (but you're then asking that 10-amp alternator to charge two batteries) or when the engines are shut down (but you run the risk of depleting both of them).

willbe asea - you just can not use only one battery on twin Honda engines (of any size); this is an absolute no-no. This isn't just my opinion; if your dealer chokes on this have him call the Honda Tech Line in Georgia (he has an 800# for them) or talk to his District Service Manager. You shouldn't have to fight a battle on this as it's clearly documented.

Les

From: Mike Sent: 4/6/2003 12:47 PM
From: LBL Sent: 4/5/2003 7:17 PM
Hi All,

As long as I'm upsetting apple carts let me tip over another one...

Do not use deep-cycle batteries as main engine batteries on any outboard powered boat. (that's a period)

There isn't an outboard made that has a regulator that's designed to charge deep-cycle batteries. Will using deep-cycle batteries hurt the alternator? Depending on which manufacturer you talk to the answer is no or maybe not. Will your deep-cycle batteries get fully charged? No. So what's the point; we've got the engine hooked up to batteries to get the engine started and to charge the batteries.

With respect to main starting batteries...there is no reason that a battery charger is necessary unless you never use the boat (batteries do self-discharge); it's an identical situation to your car. So how come a bunch of folks have to plug in a charger all the time? Either the batteries are too big or the wrong kind and the engine(s) can't keep them charged. Remember we're talking about main engine batteries here, not 'house' batteries. So how come I've got big ol' group 29 deep-cycle batteries and I never have any trouble? 'Cause you only use them as starting batteries; that is, you never draw them a long way down with loads when the engine(s) is/are shut down. Or, you're lucky (maybe you run fairly long distances). You're still damaging it though and will shorten it's life (see below).

What battery should you use for the main engine battery? A marine cranking battery. A cranking (or starting) battery is designed to accept a lot of charge over a short period of time; just exactly what the alternator on an outboard (or car) is putting out. A true deep-cycle battery needs a small or moderate charge over a long period of time; not what the outboard alternator is doing.

But you say that you heard that running a cranking battery down a few times will damage it. Absolutely true. That's where we get in to selecting a compromise. Particularly on the CD22 and CD25 we may have the engines shut down and we're drawing power from the battery (one at a time, I hope) for lights, fans, the Wallas, etc so we've got to have a battery that will take the load without damage but still get charged up by the outboard. Hence the dual-purpose battery. If you keep it maintained (the high amperage from the alternator tends to gas it off and evaporate the electrolyte) and if you run far enough to charge it when it's been drawn down this compromise usually works well. The dual-purpose battery doesn't require the extended charge that the true deep-cycle battery does and the outboard alternator will do a good job of bringing it all the way up to snuff.

So when should I choose a true deep-cycle battery? Only as auxiliary or 'house' battery and then only when you're willing to accept the fact that the engine will not be able to charge the battery fully (ever) and that a 3 or 4-stage battery charger is necessary. If you've used your deep-cycle 'house' battery overnight you can get some 'juice' back into it by selecting it with your battery switch; the engine will do the best it can but it will not bring it all the way back up (unless it wasn't down much or you travel several hours). Another problem is that if you do get the battery back up you need to de-select the battery as the high-amperage charge from the alternator will damage it. To really control charging on these deep-cycle batteries you should have a battery monitor (also called an amp-hour meter) so that you know exactly how much has been taken out of the battery and how much has been put back in; sort of the electrical version of a gas gauge.

If you have a single outboard you can have a starting battery (preferably a marine cranking battery) and a 'house' battery, which could be a dual-pupose or deep-cycle depending on your needs and willingness to charge a deep-cycle properly, or one or two dual-pupose batteries; again depending on your needs.

With twins you should have two marine cranking batteries or two dual-purpose batteries; one for each engine. You'll either need to use your dual-pupose engine batteries (again, one at a time) for 'house' use or you'll need to add a dedicated house battery or two. This get complicated and unless you really run a lot you'll definitely have to plan on a good on-board charger and stops at marinas with shore power available since it's not likely that the engine alternators can keep up with 3 or 4 batteries (unless you do run a lot).

The American myth is that bigger is better and that more is better; that's not necessarily true and with regards to batteries it can get your 'system' out of kilter. Deep-cyle batteries are not better than cranking or dual-pupose batteries (how come you don't have one in your gas-powered car?); they're just different. Choosing the correct battery (type and size) allows you to maximize the system and you'll get longer life and faster charging.

Les

From: Mike Sent: 4/6/2003 12:48 PM
From: Clamdigger Sent: 4/5/2003 10:02 PM
Hi, Les

Simply put, deep cycle batteries are just as the name implies. They are designed to be drawn down much farther than an standard "starter" battery, and (mostly) recover when they are recharged.

Starter batteries can't handle that kind of usage, and will recover fewer times.

Don't know how to measure the recovery rate of my deep cycle batteries, but the "regulator" on my 100 Merc seems to keep things fully charged, or charge them back up when they get a little low.

We may be talking entirely different electrical systems as far as other engines are concerned. I use 2 550 CCA Interstate Deep Cycle Marine/RV batteries, and have never had a problem.

But the rope is always there if I need it!

Ken

From: Mike Sent: 4/6/2003 12:48 PM
From: wilbe asea Sent: 4/5/2003 10:40 PM
LBL

I spoke with the salesman at Ak. Mining and Diving, and the upshot of all this is I now have a second battery and swittch to install in the boat (I did not feel like taking the boat 180 miles one way to leave for a week then return to get it, might get in the way of using it next weekend). Seems like a fairly simple matter, I did some mechanicing on 18 wheelers for a time, now maintain some electronic gadgetry.

The salesman was unaware that Honda had such a restriction in their installation manual, figured they had better do some research. Also found that the two battery setup had been specified at the outset by me, overlooked in the excitement of getting my new passion, and certainly overlooked by the service people at the boat vendor.

Thanks for the info, will be reading more from you in the future I am sure.

From: wilbe asea Sent: 4/11/2003 8:16 PM
Today I installed the second battery that was furnished by AMDS to complete the original order, along with a battery selector switch.

Port motor is run directly to one battery, as is the starboard motor to its own battery. Ignition wires to the start switches are run from their respective motors' batteries. Positive leads to the battery selector are run from each battery, with cabin pos. lead wire run from the third post on the switch through a circuit breaker, then to the switch panel. Negative posts are jumped together, with the ground wire from the cabin switch panel running to the "starboard" battery.

In this configuration I should be able to charge both batteries with the switch in the "Both" position, as long as only one motor is running.

Both batteries are in the starboard lazarette, eventually I will be carrying a motor for an inflaable on the port side to balance the weight. Makes for a kind of messy and crowded installation.

From: B.Anderson Sent: 5/12/2003 2:40 PM
You'll love this one..

The boat I'm thinking of buying has twin 45s and 3, yes, three, batteries with a 4-way switch. "Off", "1", "2", and "Both".

Here's the gig. The boat starts and turns off just fine in the "Off" position! Anybody with any theories? How does THAT work?

Hopefully a C-Brat soon.
Blain Anderson

From: Swanny Sent: 5/12/2003 9:28 PM
That's an easy one if my hunch is right. The engines are wired directly to each of 2 batteries. The switch simply selects which of the batteries power the electrical equipment and dash breaker panel. That's the way I had mine wired. You'll have to trace the third battery wiring to see if it goes to the switch. It could be charged by a battery combner or other arrangement perhaps. Actually this arrangement is pretty safe for the motors and their charging circuits, except don't put the switch in the BOTH position with both engines running at the same time, could violate the charging circuits by cross-feeding each other. If you have to use the BOTH position to charge a low battery from one engine, always switch it to some other position before starting the second engine.

Good luck,
Steve
CD25

From: B.Anderson Sent: 5/13/2003 5:46 PM
Thanks Steve.

I'm printing this for my boat file. Sounds good. I'll have to check it out when it gets up here and figure out what's up.

From: wilbe asea Sent: 5/14/2003 12:21 AM
That is the configuration I placed my batteries in (two of them), the switch merely selects which battery powers the dash and cabin accessories. Each motor starting circuit is independent of the switch. If I screw up and let the battery run down, I still have one battery with which to start one motor. I can then place the switch in "both" and allow the running motor to charge both batteries. Before attempting to start the motor attached to the run down battery, the switch is placed in position to power the cabin from the motor that is running, leaving the other battery (hopefully now charged) with no demands on it other than starting a motor.
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flabeachcomber



Joined: 25 Dec 2003
Posts: 23
City/Region: St. Helena Island
State or Province: SC
C-Dory Year: 2001
C-Dory Model: 22 Cruiser
Vessel Name: Kestrel
Photos: Kestrel
PostPosted: Thu May 27, 2004 5:28 pm    Post subject: Reply with quote

I too, have twin engines (Yamaha 40'2) with the three battery configuration and 4-way switch. I understand that the switch only selects which battery is to be used for auxillary equipment such as chart plotter, radar, radio, etc., but I really don't understand is how the third battery gets charged. Rolling Eyes
If anyone has a simple schematic of the three battery set-up, I would really appreciate seeing it.
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Da Nag



Joined: 24 Oct 2003
Posts: 2818
City/Region: Port Angeles
State or Province: WA
C-Dory Year: 2008
C-Dory Model: 16 Angler
Vessel Name: Taco
Photos: <a>Da Boats</a>
PostPosted: Thu May 27, 2004 6:07 pm    Post subject: Reply with quote

There's one in the Library for a pair of 2-way switches - might be a good place to start.

Link is here.

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Sealife



Joined: 03 Nov 2003
Posts: 301
City/Region: Woodland Hills
State or Province: CA
C-Dory Year: 2005
C-Dory Model: 22 Cruiser
Vessel Name: SeaLife
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PostPosted: Sun Jun 19, 2005 1:11 am    Post subject: Reply with quote

For the best discussion, with diagrams, that I've found on wiring single or twins, goto this site http://continuouswave.com/ubb/Forum3/HTML/000411.html and then click on the link in the first post. It would seem that the last setup, called the "New" setup is the most practicalble for our purposes.

Mike - Sealife

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