Three bank battery questions

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March
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Three bank battery questions

Post by March »

Hello!
I've been using a three-battery setup (one engine and two house batteries) for years. They are connected by a Xantrex Pathfinder combiner/isolator whose performance has been... spotty. Have been trying to debug the system, blaming a possibly faulty battery (I wasn't wrong) or the Xantrex remote (an expensive piece of hardware that cannot be serviced and which has burned out one of the two LEDS) Now finally the XANTREX definitely gave up its ghost. They don't manufacture or service them anymore--apparently, the relay isolators are bound to fail sooner or later.

Anyone knows of a similar device?

I would like to preserve the actual wiring that goes like this:
The engine to the engine battery. The solar panel to the house battery. The second house battery is wired to the first one through the XANTREX (I assume in parallel and it kicks in when need be)

I need a simple three-battery combiner/isolator that accepts a double source of power: the engine (start battery) and solar (the house batteries. When the engine is running and the battery is full, the combiner would switch to the house batteries and top them off. OR: when there is no engine, the solar panel charges the house batteries--when they are full, it should switch and top off the engine battery. When the house batteries are beginning to get depleted (we have two fridges) they should be isolated.

But I would also like to be able to manually connect the batteries, if need be.

Looking at the ProMariner or the Vectron FET. Anyone has any experience with them?
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ris
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Re: Three bank battery questions

Post by ris »

Not sure why on a Mac you need more than 1battery bank. We have 1 bank of 4 Trojan 105 batteries wired series/parallel. Put over 6000 miles on the water and no problems. 60 hp Honda, 2000 watt converter, sterling battery charger. If you are worried about starting your motor if the batteries die just buy one of those little small jumpers that will jump off a motor 10 times or more.
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rsvpasap
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Re: Three bank battery questions

Post by rsvpasap »

So it looks like the purpose of the Xantrex PathMaker was to automatically direct one or more charging sources (alternator, solar, battery charger, etc.) to more than one battery bank, alternatively or in combination, based upon its recognition of the amount of voltage the charging source(s) are providing. I gather it's a way to direct charge your batteries without using a "smart charger" while minimizing the risk of frying your batteries due to overcharging. I assume you have three batteries but don't use a "battery charger" at all while on the water. http://www.xantrex.com/documents/Discon ... Rev-B).pdf

So ... the Promariner Proisocharge line definitely appears to be the appropriate replacement if you want to maintain your current setup.
http://www.promariner.com/en/products/p ... rge-series

A possible alternative would be to use two Blue Sea 7650 (which includes the SI-ACR), assuming you connected batteries 2 and 3 into a single house bank. I kinda gather maybe you already have.
https://www.bluesea.com/products/7650/A ... Kit_-_120A

The Blue Sea SI-ACR does essentially the same thing as the Xantrex PathMaker, but for only one power source, so you probably need one for each power source. https://www.bluesea.com/products/7610/S ... 4V_DC_120A

I can't speak specifically to the Proisocharge, but I have a Promariner ProNautic 1250P (with five batteries, 1 start + 4 house, 100 watts of solar, shore power and a Xantrex PROwatt SW 2000). I wouldn't trade the ProNautic for anything else on the market, except maybe a ProMariner 02012 to have the inverter and charger in one box with 70 amps of charging, which is approaching the max the Honda EU2000i can put out to a charger.

The previous poster indicated he has a Sterling and is very pleased with it. Sterling is the same product as Promariner, so now Promariner already has two votes. I would reflect before combining all batteries to a single bank because two refrigerators. It's prudent to always keep something chilled.
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March
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Re: Three bank battery questions

Post by March »

Ah, it's the domino effect.I started off with two batteries and a 75W solar panel. Found out quickly that the fridge and anchor light would almost deplete the house battery by morning and--unless the sun's shining--it takes 6 hours to recharge, or start the engine

I was aiming for self-sufficiency (don't like to be tied to the dock) as a matter of principle (don't like to start the engine unless there's no wind), so adding another panel and then another battery sort of followed. And LED anchor light. Then another fridge. Then the laptop. Besides, everybody and their cousins rush to plug in their phones and recharged them while sailing.

The Xantrex combiner worked pretty well when it worked. Of course the simplest path would have been a manual 1-2-B switch, but I am a sucker for automation--until it breaks down, that is.
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March
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Re: Three bank battery questions

Post by March »

Thanks, Rsvpasap. That's good advice. Never used a charger while on the water.

ProIsocharger does take three batteries, but it seems to me that it accepts only an alternator as a power source--and it has to be wired to the engine's contact, So wiring the solar panel to one of the house batteries would probably top it off--but would it trickle into the other one as well?

Victron makes a pretty cool gadget--the cyrix CT similar to the BlueSea. I was thinking too of using one between the two house batteries and one between the engine battery and one of the house batteries. But then it dawned on me that putting a combiner between the two house batteries is kind of a moot point: if one battery gets depleted at night, the cyrix that also acts as an isolator would prevent the other one from kicking in. Right?

Seems like making a house battery bank by simply paralleling the two and treating it as one bigger house battery makes more sense. Feed it from the solar pannels. Connect it to the engine battery via the cyrix isolator/combiner which works both ways
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Sumner
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Re: Three bank battery questions

Post by Sumner »

If the batteries are all the same and about the same age I'm with Richard in that I'd put them all in one bank. You won't discharge them as much so they will last longer and will also recharge better.

If one really doesn't want to go that way at least put the two house batteries in one bank and run all the charging sources (engine/solar) to that bank and use the Blue Sea's Acr ...

https://www.bluesea.com/products/7610/S ... 4V_DC_120A

... between the banks and it will keep both charged any time there is a charging source ready. If you for some reason run the solar to the house bank and the engine to the start battery the acr will charge either direction but the best method is to run both charging systems to the house bank and let the acr keep the engine battery up.

Image

I have this on the Endeavour....

http://1fatgmc.com/boat/end-1/endeavour ... age-5.html

... but on the Mac use two 6 volt batteries in series for the house bank. If I had 4 six volt batteries they would for sure be tied together like Richard (ris) has done,

Sumner

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March
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Re: Three bank battery questions

Post by March »

Thanks, Sum. I already have the straps and trays for 12 volt batteries, so switching to six volt banks in series would require some redesigning.
I still don't understand the advantage of having the house battery charged directly from the engine, as you suggested: wouldn't that turn the house battery into an engine battery?

If I count on the Victron cyrix (or the BlueSea equivalent) to do its job, it'll switch to the house battery as soon as the engine battery is full.

A three-battery bank, as suggested by Richard, would work fine and simplify the system, if all batteries are roughly the same, like you said. But to my understanding, if one battery goes bad, it would strain and drain the other two. Whereas a separator/combiner between them would prevent this scenario.

Is that correct?
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Sumner
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Re: Three bank battery questions

Post by Sumner »

March wrote:Thanks, Sum. I already have the straps and trays for 12 volt batteries, so switching to six volt banks in series would require some redesigning.
I still don't understand the advantage of having the house battery charged directly from the engine, as you suggested: wouldn't that turn the house battery into an engine battery?

If I count on the Victron cyrix (or the BlueSea equivalent) to do its job, it'll switch to the house battery as soon as the engine battery is full.

A three-battery bank, as suggested by Richard, would work fine and simplify the system, if all batteries are roughly the same, like you said. But to my understanding, if one battery goes bad, it would strain and drain the other two. Whereas a separator/combiner between them would prevent this scenario.

Is that correct?
I'm not suggesting that you change to 6 volt batteries, especially if you only have space for 3 batteries. IF you had space and the need for 4 then yes I would suggest the layout that ris is using.

Trying to charge one battery to full and then switching to another is very inefficient as it takes a lot longer time to go from 75% discharge to 100% vs. say from 50% to 75%. Topping the batteries off takes a long time. Solar is good for that. If the two house bank batteries are tied to the single start battery with the Blue Seas Acr (which I would strongly recommend) any time the house batteries are getting a charge by either the engine or the solar the start battery will also be charged due to the fact the Acr has the batteries connected (combined).

The start battery probably won't be discharged at this point much at all as it was only used a few seconds. Even if the engine was hard starting once charging starts to the house bank charging current will be passed on to the start battery at the same time.

I see your point about the house battery becoming the start battery as with the outboard there isn't a separate wire from the charging source like there is on our diesel that has an alternator. So I agree that if you aren't going to tie them altogether where you wouldn't need to buy an acr, then run the single cable from the outboard to the start battery and let an acr combine them when outboard is running or the solar is putting out. The outboard will charge both and so will the solar as the acr goes both ways.

I would not worry much at all about one battery going down and damaging the others. Can it happen? Yes, but how often. I'd tie them together and carry the small portable start battery as ris and I and others do. I find it also useful for other things,

Sumner

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