Will This Diagram Work?

[davisr]

I've spent a lot of time researching my options. I think this will work, but I want to pass it by everyone before doing the installation.

Thanks any suggestions,
Roscoe

[Andina Marie]

Seems like you forgot to include a starting battery??

[delmarrey]

Originally Posted by Andina

Seems like you forgot to include a starting battery??

See SCS225/reserve bank, I think?

[nes]

I assume the IOTA 45 is the charger, and the ACR is an automatic charge relay. If that is the case, then there ought to be circuit breakers or overloads somewhere in the charging circuit. Otherwise assuming correct size and type of wire it looks like it will work. Depending on other loads you should have enough battery capacity for a 25 footer.

[goboatingnow]

wiring of the shunt doesn't look right. The sense wires from both side should go back to the monitor surely?

Dave

[davisr]

Hey thanks fellas for the feedback,

In response to your question about the lack of a starting battery, I plan to use the House Bank (the Trojan T-125s) not only for house loads, but also for starting the motor, and I plan to keep the Reserve Bank in reserve -- a bank to be used only in case of emergencies.

In terms of the fusing of the Iota 45 Charger and the ACR (Automatic Charging Relay), I plan to use terminal fuses on the bus bars. These are indicated on the diagram by red dots.

The terminal fuses on the bus bars seemed to be the neatest and easiest way to protect these wires, but I'm open to other suggestions.

Likewise, I'm open to other suggestions about other parts of this layout.

Regards,
Roscoe

[knottybuoyz]

Hi Roscoe

When you do a diagram like that you can leave out the negative conductors. Makes for a much clearer circuit diagram. There are a few exceptions for shunts etc.

You might want to check the instructions that came with yoru ACR for wiring. I have mine hooked directly to the battery terminals and IIRC that's the mgfr's recommendation.

Does your engine not have a charging circuit or alternator? I don't see anything other than the Iota for charging the batts.

Here's a link to a neat (and free) drawing program.

Diagramly - Draw Diagrams Online

Good luck with your project.

[davisr]

Thanks Knottybuoyz. I don't have an engine per se, but instead a Yamaha 9.9. It puts out a 6 amp charge (through the start cable), but this, of course is not enough to maintain the bank (s). So the Iota 45 is the main charging source. It is, of course, dependent upon AC power via an AC receptacle. For this I must crank a Honda EU2000 generator or be connected to shore power.

Thanks for the diagram drawing link. The program I used for the chart you see was PowerPoint. Wasn't easy, but I eventually go the hang of it.

Will check the instructions to the ACR. I've been under the impression that the bus bars would serve well and would keep things more simple at the battery terminals, but maybe I've been mistaken.

Dave, I'll check the instructions for the Victron. I believe, though, that there is only the single data cable (looks like a phone cable) that runs to the display.

Regards,
Roscoe

[mitiempo]

Originally Posted by davisr

Will check the instructions to the ACR. I've been under the impression that the bus bars would serve well and would keep things more simple at the battery terminals, but maybe I've been mistaken.

Dave, I'll check the instructions for the Victron. I believe, though, that there is only the single data cable (looks like a phone cable) that runs to the display.

Regards,
Roscoe

Dedicated bus bars are fine for an ACR - the less wires on the battery posts the better. And if the red dots on the bus bars are MRBF fuses you are good to go.

The Victron does use a single data cable unlike the Link types from Xantrex.

[djmarchand]

Roscoe:

A more common approach is to use the SC 225 to always start the engine. Then the Yamaha alternator will supply its DC current back to the starting battery and the ACR will also charge the house bank.

This way you always prove the starting battery every time you use it. Otherwise you might let the house bank run down on the hook and then when you switch over to the SC225 to start your engine and find it dead.

In other words a reserve battery that isn't routinely tested isn't worth much IMO.

David

[davisr]

The Yamaha provides 6 amps worth of charge via the starter cable. In placing this starter/charger cable on the Common terminal on the Battery Switch, I've been working under the assumption that A.) I can start the engine either with the House Bank or with the Reserve Bank, if necessary, and that B): the 6 amp charge will be distributed between the two banks. Therefore each time I use the Yamaha there will be some amps being returned to the the banks, regardless of which bank I use to start it.

I've also being working under the assumption that when charging the batteries with the Iota 45, the ACR senses the needs of each bank and distributes the charge(s) accordingly.

Have I been mistaken in these assumptions?

Thanks for the help and suggestions,
Roscoe

[mitiempo]

Roscoe

To answer the last first, the ACR closes when a charging voltage is present, paralleling the batteries. An ACR is really like a solenoid except it has specific closing and opening voltages/times. For example the popular Blue Seas SI series ACR combines the batteries when the voltage reaches 13 for 90 seconds or 13.6 for 30 seconds. It opens at 12.75 volts for 30 seconds or 12.35 volts for 10 seconds, separating the batteries. The batteries themselves determine how much current they accept.

The Yamaha's 6 amps could be sent to the common or either battery bank leaving the ACR to do the work. I commonly send all charging sources to the larger house bank as it is invariably most in need. If used for starting instead of being relegated to emergency use the SCS225 be down less than 1 AH per start.

My only further thought is that a SCS225 is more than you need for an emergency battery that will seldom be used, or even if it will be used for starting. I would put the money into the house bank as you are but would buy a group 24 start battery for $50 or $60.

[davisr]

Thanks Mitiempo for this advice. I've thought through this, and it seems I must connect the starter/alternator cable from the Yamaha to the Common. It seems I'm limited by the fact that I do not have separate starter and alternator cables. It seems that if I put the starter/alternator cable directly on the House Bank, then I would not be able to crank off of the Reserve. Likewise, if I put it directly on the Reserve, I would not be able to crank off of the House if necessary.

I went onto the Blue Seas website and looked around on some their product documents. I found a diagram with an ACR layout similar to my proposed layout. I don't have three battery switches, only a 1/2/Both/Off switch - what Blue Seas calls a "Selector Battery Switch" PN6007. At any rate, my setup appears to be similar.

Does it look like I'm on the right track, at least according to the Blue Seas recommendation?

Thanks,
Roscoe

[Stu Jackson]

Roscoe, with an outboard motor, your "ship's ground" IS the negative post of your batteries.

I agree to stay with the simple 1-2-B switch.

Here are two articles that discuss it, albeit with inboard engines.

Basic Battery Wiring Diagrams This is a very good basic primer for boat system wiring: Basic Battery Wiring Diagrams [added 9/21/11]

[added 1/31/2012] This is another very good basic primer for boat system wiring: The 1-2-B Switch by Maine Sail (brings together a lot of what this subject is all about)
1/BOTH/2/OFF Switches Thoughts & Musings - SailboatOwners.com

[mitiempo]

Stu is right about the "ship's ground" - I missed that.

I would also stick with the 1/2/both switch.

On Blue Seas site for every product that requires it the installation manual is available. It is listed as "product documents"
Here it is for the SI-ACR showing an outboard with combined alt/starter wire