Small Boat Electrical for Sail

[Stu Jackson]

Originally Posted by rgleason

1. Stu and John, I found some interesting information from Rod in his article>>>>>>>>>>>>>>>>


2. ...because the unit is accessed from the cockpit lifting seat lid, so there is a potential water issue. He mentions providing a drip shield to prevent water from damaging the charger.

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3. I have found a $35 ABS Nema WP Enclosure with hinges and lock, so the unit can be locked away safely will sailing, but have questions about how the fan intake/exhaust iworks.
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4. I have not broached the use of a inside portside cabin locker behind the seat cushions, to my dear wife. (so that locker door would have to be open when charging) -I'm chicken I guess!

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5. What about getting the remote control, would that help?

1. Which was in the links I sent you. I know the article.


2. Which is what I said last time.


3. Your boat, your choice. I wouldn't.


4. Your wife, your choice. If you simply crack thew seat cushion a bit, it should be fine unless you're down to 50% SOC when you plug in. Once you reach absorbtion the current drops, as does the heat.


5. Re-read MS's article. Maybe a few times.

[Stu Jackson]

Originally Posted by rgleason

BS SI-ACR Automatic Charging Relay - 12/24V DC 120A 7610
https://www.bluesea.com/products/761...12_24V_DC_120A

I am debating if a combiner is needed or wanted.

1. The trigger points are not adjustable in voltage, as I understand it.

They don't need to be.

1. The unit will combine when solar PV pushes voltage above 13.75v and disconnect at 12.75v and 16.0v. - I would rather not have that happen solar is to recharge the house.

The reserve/start bank is almost always FULL. Basic stuff 101. You use maybe 2 ah starting your engine.

1. If the reserve is just a simple lead acid battery and the house is AGM or something else with a different charge regimen, I don't want to combine.

Sure you can. Wet cells and AGMs have remarkably similar charging profiles. But consider YOUR case, not what may be maybes. If you have wetcells for a house bank and an AGM for reserve, no issue at all. Gels, of course. But who would do that?

1. However I want to be sure the reserve battery is kept charged.

Don't sweat it. You have 24 or more starts in the reserve bank before you hit 50% SOC. 24!!!!!!


Is there any device that would be appropriate?



Yes. a 1-2-B switch on B ONLY when charging. A combiner - Yandina is superb. Any other VSR, even an oil pressure switch and relay.


Perhaps the reserve battery should be completely isolated and voltage monitored. Then charged up when necessary by changing the regulator program and setting the battery switch to 2?



Useless, time consuming and unnecessary. And it all depends on how it's wired anyway. Your charge sources go to your house bank, IIRC, so this "on #2" wouldn't work anyway.


Any good suggestions would be appreciated.

rg, you need to reread a lot of what you already have read. I know it's a lot and all of us have been there, but you keep stumbling into "basic" questions. Maybe it's just the way you're putting them in writing, but combiner issues have been "answered" decades ago and are included in my Elec 101 and MS's website. Actually, many of us keep rereading that same stuff, too. My regulator and Link 2000 manuals are dog eared!

[rgleason]

Thanks Stu.

Yes. a 1-2-B switch on B ONLY wh, ... Alt is wired to house

Yes, that was what I meant.
[reserve/start bank is almost always FULL]
Yes, but solar is low current and reliant on time (many hours) and just "floating" an extra battery uses a lot of "juice" when actually it will be at 14.7v and we need it for the house. Therefore, I still don't want Solar connected to the reserve battery. It is a big waste of costly panel output intended for the house.

How much? Well, I just don't know, but when you are talking about using a portion, say 30-50 watts of 1200watts (2-10 amps) which is yet another loss (2-4%).

The reserve battery is secondary, I only want it combined when the engine is running!

I assume the ACR Combiner is normally open and draws 0 current.
When the batteries are being charged, voltage is sensed and rises, then the ACR draws current and holds the relay closed. It may also have a latch.

Could I run the voltage sense wires through a double pole relay that is closed when the ignition is on? That way the ACR would not close unless the engine was running. Or maybe there is some clever way of reversing the function of the SI.

In any event the simplest and cheapest solution which uses the 1both2 switch is to turn it on "both" once every two weeks to charge with the alternator. No ACR or additional wiring or fuses needed! I may simplify this part.

[rgleason]

Stu,

I just had another idea for the location of the Charger. It is a little unusual.
Behind the gimbaled oven there is a 10" deep shelf/cabinet, just below that cabinet I can put the charger and the charger will not interfere in any way with the stove. This is only about 4-5 additional feet away, making the total cable distance about 22'.

[Stu Jackson]

Originally Posted by rgleason

Thanks Stu.

Yes, that was what I meant.
[reserve/start bank is almost always FULL]
Yes, but solar is low current and reliant on time (many hours) and just "floating" an extra battery uses a lot of "juice" when actually it will be at 14.7v and we need it for the house. Therefore, I still don't want Solar connected to the reserve battery. It is a big waste of costly panel output intended for the house.



No, it is NOT. Basic battery acceptance will show you that a full battery will not drag any juice at charging voltages, be it bulk, absorbtion or float. This is NOT an issue. I recommend you go back to read the Battery Acceptance threads from us.


How much? Well, I just don't know, but when you are talking about using a portion, say 30-50 watts of 1200watts (2-10 amps) which is yet another loss (2-4%).


It is zilch.


The reserve battery is secondary, I only want it combined when the engine is running!



Of course you do, but since it IS already full, it will NOT be "stealing" anything from your solar array. Thousands of skippers have just this setup.


I assume the ACR Combiner is normally open and draws 0 current.
When the batteries are being charged, voltage is sensed and rises, then the ACR draws current and holds the relay closed. It may also have a latch.



Kinda. The ACR doesn't "draw current." It is a relay. It closes when it senses the target voltage. It simply allows current to flow, IF the connected reserve bank needs any. It usually doesn't, see above. This is all discussed in the "What are ACRS, Combiners and VSRs?" article by Maine Sail, on his website and linked in my Elec 101.


Could I run the voltage sense wires through a double pole relay that is closed when the ignition is on? That way the ACR would not close unless the engine was running. Or maybe there is some clever way of reversing the function of the SI.

In any event the simplest and cheapest solution which uses the 1both2 switch is to turn it on "both" once every two weeks to charge with the alternator. No ACR or additional wiring or fuses needed! I may simplify this part.


Don't mess with the simplicity of a combiner, ACR, or any other relay. Let them do what they are designed to do. What YOU have to do is to get your head around the concept(s), not reinvent the wheel, and understand the "power" of your 1-2-B switch. Since you have run your charging sources to your house bank, AND by the act of doing this you have made your switch a USE ONLY switch compared to a USE and Charge director, you need to find a way to charge your reserve bank, when you want to. Without spending a single $, use your 1-2-B switch ONLY WHEN CHARGING WITH THE ENGINE. Maine Sail's writeup, and mine, both say that B is for BOTH and Backup if your VSR fails. Again, the reason skippers install VSRs in the very first place is ONLY to avoid having to remember to flip the darned switch! Man, rg, how cheap is NOTHING?!? It simply becomes a MANAGEMENT issue if YOU choose to do it that way. KISS? Couldn't be easier. Done.

Interesting discussion, seems you're gettin' there. Keep up the good work.

[rgleason]

Where did that red come from? It did nor show when entered!

[rgleason]

Stu,

The ACR doesn't "draw current." It is a relay. It closes when it senses the target voltage. It simply allows current to flow, IF the connected reserve bank needs any. It usually doesn't, see above. This is all discussed in the "What are ACRS, Combiners and VSRs?" article by Maine Sail, on his website and linked in my Elec 101.

Well actually, if it is a coil and if the relay is normally open, when it is closed it is being held in in contact, so the coil is doing work. That would mean that energy is being used, or Watts are being expended. [Physics 101] Not so bad when the engine/alt is running.

Actually I have a better solution to the making sure the ACR is not on except when the Engine/Alt is running.

Install a normally open 12vdc relay in the black ACR Combiner Wire and wire the relay to the ignition circuit so that it closes when the engine is on.

"For Solar To House only, normally open 12v relay in ACR negative, for combine batteries only when engine is running.

But the "simple" BOTH Switch solution does appeal to me.

Of course you do, but since it IS already full, it will NOT be "stealing" anything from your solar array. Thousands of skippers have just this setup.

I disagree. Batteries being charged in float mode use energy, when they are being charged at 14.7v they are also using energy even if they may be "full". The energy is shown as "heat". It is a complete waste to use Solar power to charge a start battery IMHO. I want that 4% or whatever watts to go into the House Batteries. These are phantom loads like LEDS and TVs that are on when they are off. I will charge the reserve with the Alt.

[john61ct]

IMO if the energy wasted floating a full starter and/or holding the ACR closed is significant for you, there is something wrong.

But if you can rely on your memory just use a 12B switch, I can't.

Or better, put in an ACR with manual override.

Last choice, ACR plus a switch, isolate only when you find that wastage actually impacts results.

[Bleemus]

I am confused . . .

Rgleason says "How much? Well, I just don't know, but when you are talking about using a portion, say 30-50 watts of 1200watts (2-10 amps) which is yet another loss (2-4%)."

Firstly, how do you fit 1200 watts of solar on a Bristol 32?

Secondly, worrying about keeping a starter battery charged with enough solar to power a small village in Africa seems like you are worrying about something that is inconsequential.

All charge sources to house, ACR to start battery. Have a beer.

[Bleemus]

I use one of these. Get one. Have a beer.

[Stu Jackson]

Originally Posted by rgleason

>>>>>>>
Not so bad when the engine/alt is running.



Which would be just when the ACR would close.


Actually I have a better solution to the making sure the ACR is not on except when the Engine/Alt is running.

Install a normally open 12vdc relay in the black ACR Combiner Wire and wire the relay to the ignition circuit so that it closes when the engine is on.


Too complicated. Put a toggle switch in the ground wire to the combiner, which is what I did and included it in those links I sent you.


>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

But the "simple" BOTH Switch solution does appeal to me.


Least expensive, too.



I disagree. Batteries being charged in float mode use energy, when they are being charged at 14.7v they are also using energy even if they may be "full". The energy is shown as "heat". It is a complete waste to use Solar power to charge a start battery IMHO. I want that 4% or whatever watts to go into the House Batteries. These are phantom loads like LEDS and TVs that are on when they are off. I will charge the reserve with the Alt.

Disagree all you want, rg, but this is not an issue. Your energy budget should show this as 0.001% of your daily ah load.

[rgleason]

Well, I guess I deserve the responses:


Keith, you are right, it would be about 120w approx PV initially then next step another (2)135w total 390w approx


Re ACR wiring, the toggle is pretty simple, the relay off the ignition is more complex but takes care of john's point as it is automatic.


I think I'll use 12Both and try to do some measurements to try to identify these small loads.

[rgleason]

ACR Combiner
Operating Current (combine) 175mA
Operating Current (open) 15mA (24hrs a day)

Plus when it is combined by Solar PV voltage rise, there is most certainly current being used to heat up the reserve battery regardless of it being full.

These are small currents, but they can add up.

[john61ct]

The ML model I recommend is I believe zero self draw except while switching.

[Bleemus]

Originally Posted by rgleason

ACR Combiner
Operating Current (combine) 175mA
Operating Current (open) 15mA (24hrs a day)

Plus when it is combined by Solar PV voltage rise, there is most certainly current being used to heat up the reserve battery regardless of it being full.

These are small currents, but they can add up.

Isn't that about equal to a single LED bulb?