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Need help please with Victron 500A Smart Shunt readings

Ok so I wrote that several days ago but could not post it as I took a lightning strike which took out some of my wi-fi link so a bit late and out of place. I have seen many solar system failures directly due to unequal current distribution caused by non equal battery cable lengths. This is a major promlem with any lead acid battery system containing anything more than 3 batteries in parallel. If is far worse in lithium directly due to the very low internal resistance in the lithium cells as compared to the resistance of the battery cables.

On the battery monitor.....The Victron is glitzy but the data it produces is minimal.......You really need a much better battery monitoring system.

I can recommend only one.....its very good but its not glitzy.....the user interface seriously needs a update but the information it produces is far, far, far superior to anything else out there.....it is cryptic but once you figure it out you will realize its true value......

Bogart Engineering’s Trimetric........or the even better Pentametric...... ..best there is....not if and or but
These units do use a remote shunt at the battery negative and all current to and from the battery must go through the shunt so it “sees” everything. The shunt required is 50mv.
It can and does calculate the Peukert effect and can compensate for battery aging and battery effeciency


I use these on my solar system which has MidNite Classic’s and the Whizbang Jr battery monitor and the Trimetric can share the same shunt with the Whizbang jr.

The Whizbang Jr is a remote battery sensor which provides battery data to the MidNite Classic or MidNite Kid controllers, It is not compatable with your Outback equiptment. I only mention this as the TriMetric may well share a shunt with your Victron battery monitor, but I have little experience with the Victron battery monitor system. Enough to know that they are not in the same ballpark with the TriMetric or Pentametric.

Many commercial fishing boats (no solar....generator and batteries) use the Bogart Trimetric.

Bogart is a neighbor and is a very brilliant engineer but i receive no compensation from them......I know good engineering.......and do recommend them for your application.

The Trimetric does have a RS-232 output and does export data to a remote data processor, they do not have bluetooth output or monitoring.

Off the subject....love sailing, had a brown trimaran, your boat sounds like a blast....
 
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Update....just revisited the bogart site, they now do have remote monitoring via wi-fi with their adapter W-2030,

It a new product that I had not seen before so now they do have a better user interface.....well done Bogart....I did suggest it

Their solar charge controllers do have a place but are not nearly in the class of the Outback chargers that you are using...
 
Someone else here tracked down the batteries and said they are the same manufacturer as another brand which are 110-120Ah each. So I chose to be on the safe side and claim 800Ah for all eight in total. They also said to put the total as 400Ah since Lead Acid can only be used down to 50%??

Ok so I’ll change the readings to what you said and leave the rest whatever the default says?

1,200Ah nowadays is about standard for yachts. I have an extremely large catamaran. And usually 8-10 guests. Portable AC units, induction plates, lots of electronics. I bought the boat with 2,060w of Solar and 1,200Ah of LiFePo4 cells.

I’m currently in the process of testing all 1,200Ah of cells one at a time which takes extremely long. They’ve all been testing out around 85Ah each so far. I was told to match the Best with the Worst and so on. My question is, after I do that, how many Ah do I consider my system???

- Do I take the worst cell which is at 84Ah and lower down my total Ah based on that? (1,008Ah total)

- Do I take the best cell which is 88Ah and figure the entire system is equal to that? (1,056Ah total)

- Do I take the average of the best and the worst of all cells and configure the system based on the average of 86Ah? (1,032Ah total)

- Or do I still input the original Capacity of 100Ah for each cell when the system was brand new? (1,200Ah total)
You consider everything the same as the worst cell. Once the worst cell is depleted, the BMS will cut out, and anything left in any other cells is useless.

As for the capacity you enter into the Victron shunt, take your pick. All it does is affect the number displayed in the app. If you enter 400Ah, then you can run the batteries until the app says 0%, and at that time the batteries will really be at 50%. Or, enter 800Ah, and when the app says 50%, the battery will be at 50%.
 
, how many Ah do I consider my system???
Use 1000Ah and stop worrying about minor issues. You could always carry out a capacity test on the complete battery once its installed and operational.
You have made the thread over complicated by discussing both the lead acid pack and the lithium battery at the same time.
I suggest you identify, using the other thread, exactly how you are going to build the 12v battery from the 40 100Ah cells. Its important from a safety viewpoint that the battery is constructed correctly.

Mike
 
One huge problem that i see just at a glance, this will be changed when you get your lithiums back in service. But its a very major problem now.

The battery cable lengths need to be exactly the same lengths and the same guage as each wire will have a different voltage drop depending on length and guage. All battery cables MUST go to a common buss bar both positive and negative. The dirrerent voltage drops of mismatched cables ABSOLUTELY WILL cause non equal charging and will result in battery failure. 8 batteries are not recommended but in your case it is doable as you are patching yourself over.

All system chargers and all system loads must connect to the distribution buss bars both positive and negative.

The only connection between the battery positive buss bar and the distribution positive buss bar is the battery cutoff switch
The only connection between the battery negative buss bar and the distribution negative buss bar is the shunt.

I have not read the whole thread and can‘t download the photos as I am on dead slow internet at the moment but tomorrow I will review it and make more suggestions.
The parallel cables between the batteries need to be the same length? Got it. We used whatever I could scrounge because you can get this stuff in Panama.

For the Lithium, maybe you can tell me if this will work? I had thick copper bar made and 1/2” holes drilled at the appropriate lengths for 6 batteries side by side. To connect each group of 6 I’ll have to use a short 1/0 gauge wire. And the main connection between the main negative on the
Ok so I wrote that several days ago but could not post it as I took a lightning strike which took out some of my wi-fi link so a bit late and out of place. I have seen many solar system failures directly due to unequal current distribution caused by non equal battery cable lengths. This is a major promlem with any lead acid battery system containing anything more than 3 batteries in parallel. If is far worse in lithium directly due to the very low internal resistance in the lithium cells as compared to the resistance of the battery cables.

On the battery monitor.....The Victron is glitzy but the data it produces is minimal.......You really need a much better battery monitoring system.

I can recommend only one.....its very good but its not glitzy.....the user interface seriously needs a update but the information it produces is far, far, far superior to anything else out there.....it is cryptic but once you figure it out you will realize its true value......

Bogart Engineering’s Trimetric........or the even better Pentametric...... ..best there is....not if and or but
These units do use a remote shunt at the battery negative and all current to and from the battery must go through the shunt so it “sees” everything. The shunt required is 50mv.
It can and does calculate the Peukert effect and can compensate for battery aging and battery effeciency


I use these on my solar system which has MidNite Classic’s and the Whizbang Jr battery monitor and the Trimetric can share the same shunt with the Whizbang jr.

The Whizbang Jr is a remote battery sensor which provides battery data to the MidNite Classic or MidNite Kid controllers, It is not compatable with your Outback equiptment. I only mention this as the TriMetric may well share a shunt with your Victron battery monitor, but I have little experience with the Victron battery monitor system. Enough to know that they are not in the same ballpark with the TriMetric or Pentametric.

Many commercial fishing boats (no solar....generator and batteries) use the Bogart Trimetric.

Bogart is a neighbor and is a very brilliant engineer but i receive no compensation from them......I know good engineering.......and do recommend them for your application.

The Trimetric does have a RS-232 output and does export data to a remote data processor, they do not have bluetooth output or monitoring.

Off the subject....love sailing, had a brown trimaran, your boat sounds like a blast....
Your battery monitor thing sounds pretty advanced. But I’m probably selling the boat in December since I picked up new military orders and don’t need the boat sitting for 4 years. So I probably won’t install any other monitors.

Let me know if you want a 2012 Lagoon 450F that everything has been fixed. Haha
 
You consider everything the same as the worst cell. Once the worst cell is depleted, the BMS will cut out, and anything left in any other cells is useless.

As for the capacity you enter into the Victron shunt, take your pick. All it does is affect the number displayed in the app. If you enter 400Ah, then you can run the batteries until the app says 0%, and at that time the batteries will really be at 50%. Or, enter 800Ah, and when the app says 50%, the battery will be at 50%.
Got it.
The lowest capacity cell just tested at 82.98Ah sadly. That’s pretty close to being considered unusable from I’ve heard here.

Since 82.98Ah is the lowest, then my total is 995.76Ah for my system. I should be more than ok with that.
 
Use 1000Ah and stop worrying about minor issues. You could always carry out a capacity test on the complete battery once its installed and operational.
You have made the thread over complicated by discussing both the lead acid pack and the lithium battery at the same time.
I suggest you identify, using the other thread, exactly how you are going to build the 12v battery from the 40 100Ah cells. Its important from a safety viewpoint that the battery is constructed correctly.

Mike
1,000Ah it is. Looks like it’s not as big of a deal as I thought. The solar charger values will likely be the more important numbers.

I’ve figured out how I plan to build the LiFePo4 battery.
I’ve purchased copper bars that can connect 6 cells at a time, and I’ll jumper the two groups of 6 cells together with 1/0 wire. 12 cells with comprise one giant 3.2v 1,200Ah battery. And 4 of those batteries in series will make a 12v system with 1,200Ah. Nothing will be connected directly to the batteries besides the Daly 500A Smart BMS and the 500A Victron smart shunt at the last negative.
 
jumper the two groups of 6 cells together with 1/0 wire. 12 cells with comprise one giant 3.2v 1,200Ah battery. And 4 of those batteries in series will make a 12v system with 1,200Ah.
This sounds like a 'not very good idea'.
I would build a number of separate 12v batteries each with its own BMS and no more than 4 cells in a parallel group, ideally a 2P4S setup.
A 2P4S arrangement with 100Ah cells is a compact module that can be built into a restraining box to give a degree of compression, or as a minimum strapped together to give a 'mono block'.
2P4S.jpg
Mike
 
This sounds like a 'not very good idea'.
I would build a number of separate 12v batteries each with its own BMS and no more than 4 cells in a parallel group, ideally a 2P4S setup.
A 2P4S arrangement with 100Ah cells is a compact module that can be built into a restraining box to give a degree of compression, or as a minimum strapped together to give a 'mono block'.
View attachment 65170
Mike
Ugh, that sucks to hear.
I spoke to DALY BMS and they were the ones that recommended a 12P 4S system. I checked that out with the “Solar Experts” I hired here in Panama before I knew anything, and they both said it was fine as well. And everyone I spoke to said it would be a bad idea to have multiple BMS on the system because it would get confusing. Each group of 6 will have a restraining box around it and I’ve measured it perfectly since all the cells are a bit swelled and can be strapped together and not move at all. The configuration above shows 8 cells in a group and mine is only 6 compressed together. Placing things in a parallel line under a copper bus bar has less wires, less confusion,

And this way it’s less complex for anyone I hire to come take a look at it.

One of the reasons why I wanted to change the 4S 12P system I had was it’s design was the reason it went bad and wanted to change it. I already ordered the BMS months ago. It takes roughly 7 weeks to order and arrive so it’s really too late now. I don’t have any money left anyway, all of this was insanely over my budget. I can’t get 1/0 down here in Panama and everyone said hammer down copper pipe… (I used solid milled 1/4” copper bus bar which was thick and stable instead.)

I bought the boat expecting a fully working electrical and solar system and the survey checked out fine. (All they do is turn on lights and start engines and it passes the test. Which is how the previous owner fooled the surveyors who aren’t lithium experts.) I wasn’t planning a complete rebuild of everything to this extent.

Will the 12P 4S system work? Is it more dangerous? What’s the biggest issue with it that I need to worry about?
 
What’s the biggest issue with it that I need to worry about?
Failure of the single BMS.
Any if the cells in the 12P group having issues, may not be detected by the BMS.
A cell failure in the 12P group could cause the loss of the whole group.
Mechanical stress with a solid buss bar across 6 cells.
6P + 6P may have unequal current distribution.
No redundancy, a single fault, even a loose connection, will compromise the complete battery.
With connection and protection issues a great deal of energy can be released from a 1200 Ah 'cell'.

There are just some of my own thoughts, its possible others will have different views.

Having sailed 10s of thousands of miles and crossed oceans I understand your situation, and the fact at this stage, alternative strategies may not be viable.

Mike
 
Failure of the single BMS.
Any if the cells in the 12P group having issues, may not be detected by the BMS.
A cell failure in the 12P group could cause the loss of the whole group.
Mechanical stress with a solid buss bar across 6 cells.
6P + 6P may have unequal current distribution.
No redundancy, a single fault, even a loose connection, will compromise the complete battery.
With connection and protection issues a great deal of energy can be released from a 1200 Ah 'cell'.

There are just some of my own thoughts, its possible others will have different views.

Having sailed 10s of thousands of miles and crossed oceans I understand your situation, and the fact at this stage, alternative strategies may not be viable.

Mike
Before you even replied, I figured out what they told me to do wasn’t going to work. Dammit. Booking everything up in parallel like that keeps each group at 3.2v. As soon as the BMS turns off one of them, the entire bank drops by 3.2v and it’s no longer a 12v system. Rrrrgh

I’m drawing up another plan, but I’m not sure how it would work exactly…?
I have 48 cells, each one is 3.2v 100Ah nominal. I’m designing a 1,200Ah system.

I’m now thinking about making four 12v batteries that are 300Ah each and comprised of 12 cells each. All controlled by the single BMS. This creates another issue of how to balance the cells within each of the four batteries…

The previous owner had twelve batteries made of four cells each. Each battery was 12v and 100Ah. He had equalizers between group of four to balance the cells within that individual 4-cell battery. I’m thinking I could utilize those for each 12-cell battery placing one lead on each group of 3 which are parallel to balance them.

I’ll draw up a chart…
 
Failure of the single BMS.
Any if the cells in the 12P group having issues, may not be detected by the BMS.
A cell failure in the 12P group could cause the loss of the whole group.
Mechanical stress with a solid buss bar across 6 cells.
6P + 6P may have unequal current distribution.
No redundancy, a single fault, even a loose connection, will compromise the complete battery.
With connection and protection issues a great deal of energy can be released from a 1200 Ah 'cell'.

There are just some of my own thoughts, its possible others will have different views.

Having sailed 10s of thousands of miles and crossed oceans I understand your situation, and the fact at this stage, alternative strategies may not be viable.

Mike
Failure of the single BMS.
Any if the cells in the 12P group having issues, may not be detected by the BMS.
A cell failure in the 12P group could cause the loss of the whole group.
Mechanical stress with a solid buss bar across 6 cells.
6P + 6P may have unequal current distribution.
No redundancy, a single fault, even a loose connection, will compromise the complete battery.
With connection and protection issues a great deal of energy can be released from a 1200 Ah 'cell'.

There are just some of my own thoughts, its possible others will have different views.

Having sailed 10s of thousands of miles and crossed oceans I understand your situation, and the fact at this stage, alternative strategies may not be viable.

Mi
Ok how does this look…
48 cells of 3.2v 100Ah each for a 12v system for a target Ah total of 1,200Ah.

4 large, 12v 300Ah batteries comprised of 12 cells each. That way, if the 4S 12P BMS needs to cut off one of them, it’s still a 12v system. The BMS is connected to the first positive of each large battery.

How do I connect all 4 of these batteries? In parallel right? To make a 1,200Ah system…
This is what I have so far.
 

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Its not very clear to me exactly what your objective is.

The BMS in a 4S battery is connected to each cell to monitor each cell voltage and there is the control element, FETs or relay/contactor between the negative of the series connected cells and the negative of the circuit. It monitors current either with an extremal shunt or hall effect sensor, or internal within the package using resistance.

refer to this from resources,

If you only have one 4S BMS it can only monitor 4 cells, it controls the battery made up from those 4 cells in series.
Thus with a single BMS you have no option other to make up each of the 'cells' with 12 of your 100Ah cells in parallel.
As soon as the BMS turns off one of them,
The BMS will monitor each parallel set of cells but can only disable the charge and/or discharge paths to the complete battery.

Getting back to your 12P4S concept, electrically there is nothing wrong with this. As I indicated in my last post there is no redundancy so any minor failure or BMS detection of an out of range situation and either the charge or discharge path is turned off.

The original setup was 12 off 4 cell batteries each with an active balancer, QNBBM 4S Lithium Battery Balancer. From my understanding these are very effective at balancing cells connecting in series and will work in conjunction with a BMS.

It may well be the case when the battery pack was installed, using these balancers was the most effective solution at the time., creating a battery pack that that did not have the possibility of a BMS shutdown or malfunction, and having 4 cell batteries with well balanced cells over operational range. The issues you encountered may have been due to poor or inadequate physical interconnections rather than a inherent design failure. Its considered by some sea going users of lithium battery packs that battery shutdown due to BMS action is unsafe.

With suitable charge voltages and monitoring the pack voltage, you could have a system without a BMS, the boat has survived 6 years without such a system. From the cell testing you do not seem to have badly damaged cells and the capacity loss is to be expected after 6 years and perhaps somewhat neglected life.

Mike
 
Its not very clear to me exactly what your objective is.

The BMS in a 4S battery is connected to each cell to monitor each cell voltage and there is the control element, FETs or relay/contactor between the negative of the series connected cells and the negative of the circuit. It monitors current either with an extremal shunt or hall effect sensor, or internal within the package using resistance.

refer to this from resources,

If you only have one 4S BMS it can only monitor 4 cells, it controls the battery made up from those 4 cells in series.
Thus with a single BMS you have no option other to make up each of the 'cells' with 12 of your 100Ah cells in parallel.

The BMS will monitor each parallel set of cells but can only disable the charge and/or discharge paths to the complete battery.

Getting back to your 12P4S concept, electrically there is nothing wrong with this. As I indicated in my last post there is no redundancy so any minor failure or BMS detection of an out of range situation and either the charge or discharge path is turned off.

The original setup was 12 off 4 cell batteries each with an active balancer, QNBBM 4S Lithium Battery Balancer. From my understanding these are very effective at balancing cells connecting in series and will work in conjunction with a BMS.

It may well be the case when the battery pack was installed, using these balancers was the most effective solution at the time., creating a battery pack that that did not have the possibility of a BMS shutdown or malfunction, and having 4 cell batteries with well balanced cells over operational range. The issues you encountered may have been due to poor or inadequate physical interconnections rather than a inherent design failure. Its considered by some sea going users of lithium battery packs that battery shutdown due to BMS action is unsafe.

With suitable charge voltages and monitoring the pack voltage, you could have a system without a BMS, the boat has survived 6 years without such a system. From the cell testing you do not seem to have badly damaged cells and the capacity loss is to be expected after 6 years and perhaps somewhat neglected life.

Mike
My objectives:
1. Configure the system using all 48 cells of 3.2v 100Ah CALB LiFePo4 cells to create a 12v 1,200Ah system in a rectangle shape.

2. Use this system with a 3,000w Xantrex inverter charger. Have it power the system for at least 8 hours overnight. The biggest load would be a 1,100w portable Air Conditioning unit ran at night.

3. Charge this system primarily with 2,060w of 8 solar panels. 3 Outback Solar Charge Controllers are being used. A Flexmax 60A controls 2 panels. A Flexmax 80A controls 3 panels. And another Flexmax 80A controls the final 3 panels. Also, if needed, charge the system with the boat’s 5,000W Generator which would be connected to the Xantrex Inverter/Charger in case there wasn’t enough sunny days.

4. Do all this using the new 500A LiFePo4 4S DALY Smart BMS. (I only ordered this because I was told to by multiple people across multiple forums). Ordering something else is a last resort since I’m out of money and it takes 7 weeks roughly to arrive.

5. Parts I have available:
- (50) QNBBM 1S Active Battery Equalizers (See pic) salvaged from the original setup of the boat which failed. *(The original setup was 12 batteries consisting of four 3.2v 100Ah cells wired in series with each cell attached to a QNBBM, and then all 12 batteries wired in parallel to each other for a total of 1,200Ah. No BMS was used. The system wouldn’t stay on longer than 3 min with the voltage dropping from 3.6v down to 2.9v within 3 minutes and crashing the inverter.) I’m not sure I would need these if I make 4 giant batteries consisting of 12 parallel cells 3.2v 1,200Ah per battery and then wire them in series?

- 1/4” thick copper bars with six, 1/2” holes drilled to accommodate six cells in a row perfectly measured and tested to fit. (These can be cut down if necessary, but additional wire must then be used.) Two extremely thick 5’ foot tie wraps will be used to hold the pack together and stop them from moving.

- 25’ feet of black 1/0 welding wire which is highly flexible. Planning on using it to connect the group of 6 cells together to make 12 cell packs… Also, 100pc tinned copper 3/8 ring eyelets to terminate the 1/0 cable. (Using a hammer type crimping tool I purchased since the previous owner’s lever action crimp tool failed half the connectors which came loose)

- (3) Blue Sea Systems 300A isolator Switches and (5) cheap 275A isolator switches that can probably really handle only 150A

- Victron 500A Smart Shunt

- 12 position Negative Bus Bar with black plastic protector dividers between each position to free up the clutter of the 2 position bus pole which is currently being used

- Assorted In-line interchangeable Fuse Blocks with different value fuses, washers, spare cable salvaged from the previous build, Red and Black Shrink Wrap…and more misc pieces

6. Understand how this works so I can troubleshoot it if anything goes wrong. We will be leaving the Marina in a few weeks and I can’t have this go down while we are sailing like it used to fail. Our navigation gear depends on this working and so does our food storage in the dual fridges.
 
Reality check. With 2000W of solar, on a good day, expect about 600Ah of power. So that will only cover half of the 1200Ah battery, the rest will need to come from a generator. Running your A/C for 8 hours will consume 800-900Ah. So you will need the generator daily.

Realistically, you would need 6000W of solar to support a 1200Ah Lithium bank. 4000W to support 1200Ah, and another 2000 to recharge the batteries (over two days, while still supporting your load) after a day of rain. With your current setup you only have 600Ah of power you can use every day, anything more than that will come from the generator.

Just so you understand, with your current parts your goals cannot be met. Of course, you can still make all of your parts work, but expect to run the generator for several hours every evening and every morning as a primary charging source.

Your dilemma seems to surround whether you should go 12p4s, or 4s12p, or something between those. That isn't any easy question, as there are drawbacks to anyway you do it. My biggest issue with 12p is that you have old worn out cells. If one of them fails as a short, there is no way to know. The BMS won't be able to protect from it, and you will have 11 cells directly shorted though the 1 failed cell. That will cause a fire you will be unable to control, and you will loose the boat. 4s12p will protect from that scenario. There are lots of other arguments about keeping the cells balanced, and sharing current equally, keeping all the wires the same length, etc. With 48 old unmatched cells, you are going to have balance issues over time, so that really doesn't matter. You also have some active balancers to take care of those issues.

12p is a lot of cells in parallel. I wouldn't recommend that, even with new cells. But, it will work "ok." That is, It won't work well, but will be ok(ass long as a cell doesn't short). If it were me, I would build 4 packs of 3p4s. You will need 4 BMS's instead of 1, but that is better than needing 12 of them. You will have redundancy if a battery fails and the BMS disconnects it. It is much simpler to build and wire than 12 4s batteries. As for the potential fire issue, the only way to protect from that is 4s12p. But, calb are really well build cells, and shorts are rare. So it is unlikely, but could happen.
 
Reality check. With 2000W of solar, on a good day, expect about 600Ah of power. So that will only cover half of the 1200Ah battery, the rest will need to come from a generator. Running your A/C for 8 hours will consume 800-900Ah. So you will need the generator daily.

Realistically, you would need 6000W of solar to support a 1200Ah Lithium bank. 4000W to support 1200Ah, and another 2000 to recharge the batteries (over two days, while still supporting your load) after a day of rain. With your current setup you only have 600Ah of power you can use every day, anything more than that will come from the generator.

Just so you understand, with your current parts your goals cannot be met. Of course, you can still make all of your parts work, but expect to run the generator for several hours every evening and every morning as a primary charging source.

Your dilemma seems to surround whether you should go 12p4s, or 4s12p, or something between those. That isn't any easy question, as there are drawbacks to anyway you do it. My biggest issue with 12p is that you have old worn out cells. If one of them fails as a short, there is no way to know. The BMS won't be able to protect from it, and you will have 11 cells directly shorted though the 1 failed cell. That will cause a fire you will be unable to control, and you will loose the boat. 4s12p will protect from that scenario. There are lots of other arguments about keeping the cells balanced, and sharing current equally, keeping all the wires the same length, etc. With 48 old unmatched cells, you are going to have balance issues over time, so that really doesn't matter. You also have some active balancers to take care of those issues.

12p is a lot of cells in parallel. I wouldn't recommend that, even with new cells. But, it will work "ok." That is, It won't work well, but will be ok(ass long as a cell doesn't short). If it were me, I would build 4 packs of 3p4s. You will need 4 BMS's instead of 1, but that is better than needing 12 of them. You will have redundancy if a battery fails and the BMS disconnects it. It is much simpler to build and wire than 12 4s batteries. As for the potential fire issue, the only way to protect from that is 4s12p. But, calb are really well build cells, and shorts are rare. So it is unlikely, but could happen.
Got it.
So for safety reasons, there is no getting around not adding more BMS modules. I’ll need to immediately order them ASAP.

If I built 4 packs and went 3P 4S:
1. What Amps of BMS should I purchase?
2. I would need four of them, can I use the existing 500A 4S DALY smart BMS I already bought as one of the four?
3. Is there anything special I need to purchase to make four BMS modules work together? Any additional parts? I need to make sure I order everything now.
4. Anything else I need?
 
On the battery monitor.....The Victron is glitzy but the data it produces is minimal.......You really need a much better battery monitoring system.
But the victron is not a battery monitoring system at all.

It's primary value is an accurate aggregate state of charge of a system with multiple batteries. Something individual BMS units on each battery typically don't integrate together to accomplish.
 
You are talking about a completely different Victron product than I am, or I am talking about a completely different Victron product than you are. I have had a Victron battery monitor side by side with the TriMetric and there is a huge difference. But they both count charge amps and discharge amps, calculate totol charge, total discharge, perkuit , ect.

This has nothing to do with a BMS at all, just the whole battery , not the cells

What Victron product are you talking about.....

Sorry for the confusion on this issue..
 
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You are talking about a completely different Victron product than I am, or I am talking about a completely different Victron product than you are. I have had a Victron battery monitor side by side with the the TriMetric and there is a huge difference.
Good thing this thread is about a smartshunt then.
 
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