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Sorry to hijack / revive this thread, but I have a similar mission and setup (48X 100Ah Fortune, 6X JBD BMS but not the Overkill model, 2X MPPT, SmartShunt, 2X Orion Cerbo GX) and am hitting a similar wall: How to efficiently (i.e. not going overboard in terms of complexity) yet safely connect...

Little intermittent update: got word back from the VRC-200's manufacturer: "You are correct in your interpretation. You can plug a VRC-200 into your Mitsubishi alternator(s), but not into one that was previously fitted with an external field controller because those have no regulator any more."...

Ah, yes, no, I was indeed talking about 2 alternators per engine. I just did some digging and it indeed doesn't seem to be a problem! If I go down the DC-DC route I will indeed definitely go with Orions. For now I'll just stick to solar charging (should be fine with the sunny seasons coming up...

Cool, thanks. I was thinking it may be possible that 2 alternators on one engine puts unnecessary extra strain / resistance on the engine. But if it doesn't, all good. Right, makes sense. Shore power will be virtually non-existent to us (we aim to anchor 99% of the time), so having at least one...

I don't know what I want because I don't know what I'm talking about ? But the way I see it. My 2 most viable / practical options are: Only keep the 115A alternators and remove the other ones, then hook those up to the charger batteries -> DC-DC converter -> MultiPlus Keep both alternators...

Yes I forgot to mention that rather important little detail, lol. Yeah it's a bit vague, but I'm reading nothing but good feedback from users on it. From what I understand, it's initially designed for alternators with built-in regulators, which our alternators do have (although they only...

My idea was that the alternators charge the starter batteries, and when those are full, the charge continues to the house bank, which would also make the starter batteries work as a buffer to soften the sudden BMS cut-off. As an alternative, instead of buying 2 Wakespeeds, I would probably go...

I'd have to check, but I believe it's now setup to be connected to the LFP bank. Either that or to the starter battery. Definitely no separate battery though (there is none). Makes sense indeed, although if I understand correctly, this will eliminate the option of monitoring every individual...

I'll see if that's still doable. Potential bottleneck here is that the windlass is on the front of the boat, and the batteries in the stern. That's mucho metros of high power 12VDC wiring that needs to be added / fed thru the boat, which is not an attractive idea. Lol makes sense. So far so...

Wow, this is quite the plot twist! I have literally never heard of this concept. Thanks for the clarification @Rocketman and thanks for the further dissection @Horsefly. 2 things that come to mind directly when I'm reading this: 1. Is there really a difference in viewpoint on boats vs...

Ah, right. I think there’s a misconception here. To reiterate: I have 14 BMS units, so one per 4 cells, i.e. per individual battery, not one for the entire bank/group. This means I should theoretically be able to pull 14 X 150A = 2100 amps, even if I build one bank, right? Ah yes, course. That...

Right, so what you're saying is with one bank it's harder / impossible to draw as many amps than from smaller banks, correct? Is that due to resistance? Regarding charging: is it okay / advisable to use the Multiplus to top balance the cells as well (while closely monitoring each cell's /...

Okay, but what I mean is: as a principle, why is it generally better to have multiple smaller groups of batteries than one bigger group? You say 'in sync'. Do you mean that it will be easier for the system to keep the SoC over all the batteries at an equal level?

You're right, they don't. The windlass and winch (we don't have bow thrusters or any other high power DC equipment) most definitely won't draw more than 100~150 amps, will never run for longer than a minute or so, and are very unlikely to be used simultaneously. So, assuming that a winch or...

Yup! Like I said - I could fit twice as many cells in the compartment that they're in now. Naaah, I think I'll just order 8 more cells and go for 4p4s4p ? Although it may take a while before they arrive, so a temporary setup would be desirable at least, since we're going into the water on March...

Yes, and there's a wonderful solution for this when powering devices like these to LFP batteries: Softstart. It's also a commonly used solution for boats with A/C for instance (which we don't have btw). Not sure. At this point I indeed highly doubt that we'll exceed 500A (probably the highest...

Lol, yeah sorry, had some wines. MasterShunt SmartShunt, obviously. Yup. So better go with the 1000A I presume, just to be safe?

Thanks for the clarification @Horsefly, makes sense. I really wonder why my marine electrician was so adamant about any type of shunt being totally redundant because I already use BMS ?‍♂️ (before anyone asks: he had to leave to Grenada for another project before he could finish our install...

I can't find it right now but in a different thread I read that the BMS readings are often not very precise (something about 'based on coulombs') and that placing a shunt between it provides more accurate measurements. But perhaps I read / remember it wrong. This project is so overwhelming that...

Alrighty then ?

Ah, so SCC = MPPT. Gotcha. Again - with 2000W total solar power (even if realistically not true 2000W) I am indeed not too worried about small voltage drops. It's wire bulkiness that I'm worried about. I guess I'll just need to find a way to figure out how much space I will have for the wires...

That's becoming the million dollar question. The tricky thing is that the hardtop bimini's support tubes are being re-made and aren't currently mounted onto the boat yet, so I don't know exactly how much / little room I'll have to feed the cable thru. However, I need to order and install the...

Doh. Because you place the MPPTs as close to the batteries as possible. Silly me. Yeah no I will indeed keep the batteries 12V. Just wanted to keep the run from panels to my battery compartment (where all the other power management stuff is located as well) as simply and light as possible. And...

UPDATE: Found out that my TrinaSolar panels actually in fact have bypass diodes integrated into their junction boxes! Which would make the concept of connecting them in series more appealing, despite possible partial shading, right? Apart from the salt water environment thing of course... But I...

But...wait..24V needs less thick wires than 12V (right?), so if the bundled 12V wires won't fit through the bimini support tubes' mounting hole, 24V wires should/might/could (right?). Thanks Rocky. I assume you mean I should have the batteries managed individually by BMS and as one large batter...

Hi all, first off - thank you so much for all these insights and suggestions, and sorry for the long downtime. Life happened. But we're back to picking up this subject as of tomorrow as we need to order supplies in order to receive and install them in time before we're hauled back into the water...

Interesting, I didn’t know that, thanks! Didn’t know that either, sweet! With that being said, the electric winch and windlass won’t be used at the same time, and always during relatively short bursts only (<30 seconds). Naaah, not necessarily… Absolutely! Also interesting! Will definitely...

Thank you for your insights @rmaddy, that's very helpful start already! You response kind of confirms my assumptions on 24V vs 12V. With that being said, please allow me to respond to a few points: I get why it would be best to connect them parallel would be best if one/some of them get shaded...

Hello everyone, Although I would describe myself as someone with interest and affinity for all things tech, I'm quite inexperienced when it comes to electrics. Also, I'm great at languages i.e. I suck at making calculations. I also haven't participated much on forums in general thus far, so...