Might already be covered but head is spinning - charging system!

[jkimbu]

Hello all! Please pardon the 279,31st ask of a similar question....

My new-to-me 1988 Bristol came with a mysterious hand-drawn diagram of what the charging system looked like "at some point in time". It has been changed a little bit, and the 1st picture below is a crude diagram of the current (see what I did there?) state of affairs:

https://www.dropbox.com/preview/Public/sonnet_as-is.PNG

And the 2nd one below is what I think it should be (the genset alternator output should go to the genset battery so that it can charge when the genset is running not just when that switch is closed (although the switch has to be closed to start the geneset, so...)):

https://www.dropbox.com/preview/Public/sonnet_should-be.PNG

As you can see, the engine battery only charges when the engine is running or that 'normally off' switch is on, and the genset battery only charges when the genset is running. As we are presently on shore power most of the time, what happens is the two start batteries slowly lose juice. So, I want to add a pair of ACRs, to share the charge current that goes to the house bank with the two starting batteries, as per the 3rd picture, like so:

https://www.dropbox.com/preview/Publ..._with-acrs.PNG

Is that correct? Of course the ACRs would be fuse protected (I tried to indicate that with the ~ACR~ label). And I'd probably bring all the charge sources to a positive bus and tie that to the house bank, not stack all those connectors on a terminal, but you get the idea.

To make it more complicated, the house bank is getting ready to be replaced with 6 carbon foam Fireflys... which of course have different charge parameters from the starting bank.

I appreciate any and all input here... this forum is fantastic!!

Cheers,

JB

[smac999]

The as is drawing looks great. Don't touch it.

Moving the gen alt cable sevrves no propose what so ever

Add a small 2 bank ac charger for start battery and gen battery. Or that inverter may already have echo charger outputs to use? Designed to charge other banks. I've never seen a 2.0 charger. Do you have 2 inverter chargers? One is wired as charger only? One of those may have echo charger built in.

I would not add acrs when you already have separate alts for engine and house. Never add an acr to a gen battery. A gen alt should not be charging house batteries.(it would if you added acrs) Only topping up the gen battery. If you don't want to add an ac charger. Install an echo charger from house to gen battery. (Make sure it's connected in corect direction)

The 160a one should be external regulated if not already.

If you really want more house charging. (From house and engine alt) You could add an acr between house and eng. but then both alts need to be external reg for the fireflys. Switching on the parallel on the rare times you want both charging house could also be done instead of acr.

[jkimbu]

Hey thanks smac!

Moving the generator alt cable would make it so that if, after starting the genset, someone moved that switch to the off position, the generator alt would still be charging the generator battery... but that's all it would do, agreed.

I neglected to include the regulators - the 2 engine regulators are externally regulated, I need to check on the genset one.

There are no echo charge capabilities present (there was a different inverter/charger on the boat before, apparently, that did have echo charges to the engine and genset batteries, but it's long gone).

There is one inverter/charger, which is acting as inverter only generally - that's the Xantrex SW3000. The main issue with that is that both 30A shore power leads need to feed into that, but the way it's wired up only a single one of those 30A leads is effectively providing the inverter AC loads *and* the power to the charger (which is indeed a Prosine 2.0 inverter/charger/ wired only as a charger).

My actual plan is to install twin Xantrex SW3012 inv/chargers so as to get 6000W available on the inverter circuits so that more of the "luxury" loads can be accessible when not on shore power. With the Fireflys and an ample helping of solar, I should be able to manage keeping things comfy quite well without daily genset or engine running.

I do at least *need* something that keeps the genset battery charged. At present, the generator rarely runs (only to run the hydraulic bow thruster, go figure) and since nothing charges that battery, I have to combine to start nearly every time, and it never runs long enough to bring that battery back (for example, this winter, due to winterizing the genset raw water system, I anticpate 4 months without running the genset - that battery is going to be veyr low (even though it's only a year old - that's a lot of just sitting!). I could do that with as you say with an echo charger, I hadn't thought of the small dedicated 2-bank charger for the two start batteries - that's a lot cleaner than the other options...

What I do now is mostly leave the "mostly off" switch mostly on, so that my engine battery is always fully charged (from shore power).

Thanks for the ideas... !!

- Jeff

p.s. Just realized, I currently don't use the charging function of the SW3000, nor the inverting function of the Prosine 2.0. I could take the charging output of the SW3000 and put it to the genset battery instead of the house bank... that would solve that problem by moving one cable! I could also take the invert output of the Prosine and put it on a couple of the non-inverter AC circuits... that might address most of my concerns with respect to luxury power without having to buy two brand new inverter/charger$$!

[smac999]

The inverter charger has one cable. If you moved it to the gen battery. The gen battery is now doing the inverting.

[smac999]

With dual 30a plugs the 2 brand new inverters can not be used anyways as you are probably hopping . You can't stack them in series or paralell because some times those 30a plugs will be in phase (120v). And sometimes out of phase (240v).

Unless you want to be reprogramming and testing them at each different dock.

So you'd have to treat each 30a plug and panel as 2 totally different systems. Which you can already do with your existing 2 different ones.

[jkimbu]

Originally Posted by smac999

The inverter charger has one cable. If you moved it to the gen battery. The gen battery is now doing the inverting.

smac: BOTH devices are inv/chargers... it's just that the SW3000 is currently used for inverter only. So the idea would be to have the SW3000 also do charging of the house bank, and have the Prosine 2.0 (currently only doing charging) charge the genset instead....

[jkimbu]

Originally Posted by smac999

With dual 30a plugs the 2 brand new inverters can not be used anyways as you are probably hopping . You can't stack them in series or paralell because some times those 30a plugs will be in phase (120v). And sometimes out of phase (240v).

Unless you want to be reprogramming and testing them at each different dock.

So you'd have to treat each 30a plug and panel as 2 totally different systems. Which you can already do with your existing 2 different ones.

Actually the new Xantrex SW 3012 can in fact be stacked in parallel to provide 2x the charging output and inverted power, but you are correct, I had overlooked the fact that I already have two inverter/chargers (because each one is only used in one mode right now). I'd have to think about which circuits to put on which inverter, 2000 watts on one and 3000 watts on the other, instead of 6000 watts shared across all, but maybe that's not so bad. Certainly better than $3000 worth of new inverter/charger that I could use for a watermaker!!!!

Cheers and thanks! I'll update the diagrams here pretty soon....

[smac999]

Originally Posted by jkimbu

Actually the new Xantrex SW 3012 can in fact be stacked in parallel to provide 2x the charging output and inverted power, but you are correct, I had overlooked the fact that I already have two inverter/chargers (because each one is only used in one mode right now). I'd have to think about which circuits to put on which inverter, 2000 watts on one and 3000 watts on the other, instead of 6000 watts shared across all, but maybe that's not so bad. Certainly better than $3000 worth of new inverter/charger that I could use for a watermaker!!!!

Cheers and thanks! I'll update the diagrams here pretty soon....

There is no good way to stack them with dual 30a shore plugs.

[AndyEss]

For trickle charging and maintaining your genset battery, why not add a small solar panel dedicated just to this function?
You say you don't use the genset much, except to run the bow thruster, so a small 20 W panel might keep that battery charged and ready to go.

[jkimbu]

Originally Posted by smac999

There is no good way to stack them with dual 30a shore plugs.

Well according to the installation manual I can supply the SW 3012 with either two split-phase 30A inputs or two in-phase 30A inputs.

[jkimbu]

Originally Posted by AndyEss

For trickle charging and maintaining your genset battery, why not add a small solar panel dedicated just to this function?
You say you don't use the genset much, except to run the bow thruster, so a small 20 W panel might keep that battery charged and ready to go.

Possibly... there will be 3 good-sized solar panels, each with its own controller - I don't know that I want to dedicate 1/3 of all of the excess output to maintaining the genset battery when I could do it as easily with an ACR (or trickle charger) between the house bank and the genset battery - I can see that I don't want/need an ACR for the house+engine battery (I kinda sorta have that functionality already with the 'normally off' switch).

That said, I don't run the genset much *now* while we're on the dock. Once we're out cruising and less shore-bound, I expect I'll be running it every 3 days or so to top up the batteries, and in that mode I think the genset battery will be fine - it's just while we're away from the boat for long periods of time that is an issue.

[smac999]

Originally Posted by jkimbu

Well according to the installation manual I can supply the SW 3012 with either two split-phase 30A inputs or two in-phase 30A inputs.

That is one inverter. Not stacked. But still will not work.

Try it with on board elci breakers (which boats should now have). Or gfi dock breakers (which US marinas are changing too). And let me know what happens...

You can't re combine neutrals after they go through a breaker.

Stacking has those issues plus others as well.

The best option is one independent inverter from each shore plug feeding its own panel. Each inverter with own screen and control. No connection or stacking. You can already do this with what you have. You can choose to split each plug into inverter or non inverter loads. Or invert all.

Or moving all non inverter loads to one shore plug and own panel. And feeding the 2nd shore plug to both inverters stacked in parallel and to own inverter panel. But now all your charging and chosen inverter loads are limited to 30a on shore. But you'd have 6000w of inverter to inverter panel when away.


Or upgrade to 50a 240v shore. Then you can follow the 3 choices in the manual.

[jkimbu]

Originally Posted by smac999

That is one inverter. Not stacked. But still will not work.

The Xantrex website (Victron too, for that matter) explicitly touts stacking two or more inverters, either in series (not what I'd want) or in parallel (see pp. 48-53 in the installation manual for wiring diagrams if you like). In series, "120 volts AC is available (at 30a) from each inverter or 240 volcts AC is available across the ouptut line terminals of the stacked pair", whereas "a parallel stacking configuration allows the inverter and charger capacity of a system to be doubled."

I (and others!) would be very interested in what about that technology you think isn't going to work in this case - that is, what am I missing here?

Originally Posted by smac999

The best option is one independent inverter from each shore plug feeding its own panel. Each inverter with own screen and control. No connection or stacking. You can already do this with what you have. You can choose to split each plug into inverter or non inverter loads. Or invert all.

This has the limitation that I have to make a one-time permanent decision about which circuits are fed by which inverter. The very problem I'm trying to fix! (And which would be fixed by replacing the two inverters with a pair that are designed to be stacked to explicitly address the limitation).

Originally Posted by smac999

Or moving all non inverter loads to one shore plug and own panel. <snip> But now all your charging and chosen inverter loads are limited to 30a on shore.

This is effectively what I have now (see diagram below that I didn't originally share), except that I have one set of non-inverter loads which are fed with one of the shore plugs, and the remaining non-inverter loads and all inverter loads effectively fed by the other shore plug. I say this because the only time I get any indication that current is being drawn from shore power #1 is when I run something on the non-inverter circuits 1-4 on the left side of the AC panel. If anything is running on 1-4 on the right side, or the charger (5 on the right) or on any of the inverter circuits (6-8 on either side), I see current being drawn from shore power #2, and if that current exceeds 30a then that (correctly) pops that breaker. This is the limitation that I am trying to resolve!

Originally Posted by smac999

And feeding the 2nd shore plug to both inverters stacked in parallel and to own inverter panel. <snip> But you'd have 6000w of inverter to inverter panel when away.

I'm not tracking that one... nowhere do I see an indication that I can connect a single 30a shore plug to two inverters.

Originally Posted by smac999

Or upgrade to 50a 240v shore. Then you can follow the 3 choices in the manual.

I do have a 50a 240v input on the boat. I've yet to trace that side but I strongly expect that the two 120v legs of that 240v input are split and feed the two inverters just as though it was two single inputs.

I do appreciate your thought and inputs here! In addition to the more detailed AC panel diagram, I've attached is a slightly updated version of what the current situation is, along with what I think I'm going to do going forward - basically we decided that the small amount of additional flexibility gained with a pool of 6000W of inverter power spread across all the inverter loads while offshore (vs. 5000W allocated into a 3000W set and a 2000W set after I connect the inverter output of the Prosine to some presently non-inverted circuits) isn't worth the $3000 for a pair of new inverter/chargers. Especially considering that running 6000W of inverter-powered devices would kill my battery bank in one hour! **NOTE** The images should say MPPT controllers, not PWWM.

Big decision is whether to trickle charge the genset battery from one of the solar controllers with overflow current (v2a) or to just use one of the ACRs that I have but haven't installed (v2b).


Cheers!

[smac999]

You will understand my warning the first time you go to a marina with gfi breakers. (New code). Or upgrade your boat ones to elci. Your current system will stop working and you will have no shore power on board.

The 50a 240 will not have this issue as the netueal is always common with both lines . Vrs being split, breakered, and rejoined. All your drawings are missing the double pole 30a main breakers that your boat will have. which is much different then the single poles in the diagrams.

[jkimbu]

Originally Posted by smac999

You will understand my warning the first time you go to a marina with gfi breakers. (New code). Or upgrade your boat ones to elci.

Your current system will stop working and you will have no shore power on board.

And yet in your first reply you said my current system was "perfect, don't change it". Confused!

Don't get me wrong here, smac - I definitely am up for learning, but you're just saying "do this, don't do that" and that's not teaching, that's telling. The above statement seems counter to the specific installation instructions put out by a couple of large reputable electrical system supply houses. So I'm not ruling your comment out out of hand, but some explanation would be really helpful to all concerned!

Originally Posted by smac999

The 50a 240 will not have this issue as the netueal is always common with both lines . Vrs being split, breakered, and rejoined.

What issue? The manual I referred you to online clearly states "don't join the (input) neutrals", and I never said I never said "hey let's join the neutrals!" so I'm not sure where this concern is coming from.

Originally Posted by smac999

All your drawings are missing the double pole 30a main breakers that your boat will have. which is much different then the single poles in the diagrams.

My AC panel diagram clearly shows two 30A input lines, each with its own breaker.

For your edification, here's a link to the Xantrex page, which has a link to the Installation Manual (to which I've been referring) for reference for all. Would love to know specifically which parts of that manual are making statements that will result in the failures you're warning me about!!!

Inverter Charger | Freedom SW Inverter/Charger | Xantrex

I feel like the last thing I decided to do was the very thing that you said was the "best approach" and now you're saying whatever I do I'll be sorry. Not the most actionable information!

Thanks very much for your patience... I know you have good stuff to say and I'm just being obstinate in trying to understand it!