Need help please with Victron 500A Smart Shunt readings

[Tecnodave]

That is what I read in the OP’s post “Victron Smart Shunt“

 

[Tecnodave]

Did I miss something, OP is asking advise for the whole system, is that not what I was talking about, part of the system?

 

[Short_Shot]

Did I miss something, OP is asking advise for the whole system, is that not what I was talking about, part of the system?

Yes. A smartshunt is not a BMS and has its place alongside any other type of BMS.

 

[Tecnodave]

I have never said that a smart shunt was a BMS, never.....I am referring to the Victron smart shunt the OP referred to in post #1. I see major problems with the proposed 16 cells in parallel but only pointed out how that many cells in parallel will cause balance problems between the cells in parallel but if you noticed i refrained from commenting on that further.

 

[TommyHolly]

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.

Sounds good. I've re-designed the system now to have 4 batteries of 3P 4S. (12 cells in each battery, 300Ah 12v). And the four batteries connected in Parallel for a total of 1,200Ah 12v (48 cells total). I'll need my Victron 500A Smart Shunt to give me an aggregate state of charge for all 4 batteries in my system together.

 

[Short_Shot]

I have never said that a smart shunt was a BMS, never.....I am referring to the Victron smart shunt the OP referred to in post #1. I see major problems with the proposed 16 cells in parallel but only pointed out how that many cells in parallel will cause balance problems between the cells in parallel but if you noticed i refrained from commenting on that further.

You explicitly called referred to it as a battery monitoring system, or rather that it's insufficient and OP needs something better.

However. The smartshunt has nothing to do with individual cells. That's the job of the BMS.

I'm simply stating that your comment about the smart shunt not being appropriate for the task is incorrect and that it has its place in addition to a BMS which would take care of the cell issues you mentioned.

You correctly stated that OP needs more BMS units though. I was simply pointing out that the two go hand in hand.

 

[Tecnodave]

Yes. A smartshunt is not a BMS and has its place alongside any other type of BMS.

can you tell me exactly how a smartshunt is not a BMS and has its place alongside any other BMS

we were discussing what was causing his massively parallel flooded lead acid bank to be out of balance

I do not understand what a BMS has to do with a bank of 12 volt batteries in parallel.....

I have seen a BMS on a 48 volt bank of Rolls Surette 1100 a.h. 2 volt cells but never on a 12 volt battery

Exactly how do you do that?

 

[TommyHolly]

I have never said that a smart shunt was a BMS, never.....I am referring to the Victron smart shunt the OP referred to in post #1. I see major problems with the proposed 16 cells in parallel but only pointed out how that many cells in parallel will cause balance problems between the cells in parallel but if you noticed i refrained from commenting on that further.

The product I've been talking about is a 500A Smart Shunt like I mentioned in the OP. I didn't know a battery monitor existed or what the difference is between the two or why you would need one and not the other which is why I'm confused. And don't worry, I never thought anyone said a BMS is a smart shunt, I know the difference.

I've re-designed the system now to have 4 batteries of 3P 4S. (12 cells in each battery, 300Ah 12v). And the four batteries connected in Parallel for a total of 1,200Ah 12v (48 cells total). I'll need my Victron 500A Smart Shunt to give me an aggregate state of charge for all 4 batteries in my system together.

Here is a screenshot of my latest revision for the configuration which people helped me with in the other post:

 

[Short_Shot]

can you tell me exactly how a smartshunt is not a BMS and has its place alongside any other BMS

we were discussing what was causing his massively parallel flooded lead acid bank to be out of balance

I do not understand what a BMS has to do with a bank of 12 volt batteries in parallel.....

I have seen a BMS on a 48 volt bank of Rolls Surette 1100 a.h. 2 volt cells but never on a 12 volt battery

Exactly how do you do that?

A BMS monitors the cells within the battery.

The smartshunt monitors the the the system capacity outside of the BMS.

In a bank of 12v batteries, each battery can have its own BMS. From there each bms will connect to one single shunt.


If you buy a pre-built lithium battery (like a 12v renogy or Battleborn) it will have a BMS built into its case.

A smart shunt is not a BMS.

 

[Tecnodave]

OK i see the issue

There are two totally different types of BMS

BMS as it is properly used is a Battery MANAGEMENT System

not a Battery MONITORING system such as the Victron Smart Shunt and the TriMetric which also has a shunt on the battery negative cable as well as connection to voltage wires in the system so they both can see the total current in and out of the battery

 

[Tecnodave]

Why do you keep saying that.....I never said that....what is your issue?

 

[Short_Shot]

Yes.

Your statement implied the victron was insufficient and should be replaced with something to monitor cells at an individual level.

The part about cell "monitoring" or management was correct, and I was just adding that the victron would still be utilized in that scenario.

 

[Short_Shot]

Why do you keep saying that.....I never said that....what is your issue?

Because you bunched the victron in with your comment about cell monitoring.

 

[Tecnodave]

The product I've been talking about is a 500A Smart Shunt like I mentioned in the OP. I didn't know a battery monitor existed or what the difference is between the two or why you would need one and not the other which is why I'm confused. And don't worry, I never thought anyone said a BMS is a smart shunt, I know the difference.

I've re-designed the system now to have 4 batteries of 3P 4S. (12 cells in each battery, 300Ah 12v). And the four batteries connected in Parallel for a total of 1,200Ah 12v (48 cells total). I'll need my Victron 500A Smart Shunt to give me an aggregate state of charge for all 4 batteries in my system together.

Here is a screenshot of my latest revision for the configuration which people helped me with in the other post:

I am responding to @TommyHolly here

The Victron Smart Shunt is a battery monitor , the same as the Bogart Engineering TriMetric is a battery monitor.

There seems to be some confusion about a battery monitor vs a BMS....Battery MANAGEMENT System

You need the BMS on each battery but the whole system of 4 batteries need a battery monitor.

What I said is in my opinion is that the Bogart Engineering TriMetric Battery Monitor is far better than the Victron Smart Shunt (a battery monitor)

 

[Short_Shot]

Or perhaps you were simply talking about individual battery packs and balancing those exclusively?

OP has individual cells to contend with which further complicates things.

At any rate this whole argument is stupid. The only point of my statement was that the victron shunt still has its place alongside any other balancing or individual pack monitoring solution up until that solution includes a total system readout (which of course some of them do).

However having cell balance issues would be resolved by his plan to separate the cells into multiple battery packs and monitoring each cell individually.

This will allow each pack to shut off individually if any one cell discharged too low, but we would need to be sure that any one pack can handle the current needs of the system just in case the others are all shut off.

And he will need to top balance each pack of course.


Further imbalance between packs can be resolved by choosing a bms which can be paralleled with another and perform active pack balancing OR installing a separate pack balancer like victron and others make.

 

[Short_Shot]

What I said is in my opinion is that the Bogart Engineering TriMetric Battery Monitor is far better than the Victron Smart Shunt (a battery monitor)

What does it do that the smartshunt does not?

If it balances packs then absolutely. If it does not balance packs (and I didn't see that on its features) then the only significantly better feature is slightly better data logging and wifi.

No sense to me in ditching the victron if it's already paid for unless he needs that slightly better logging.

It DOES offer better wireless range though (doesn't use Bluetooth and victron really sucks for Bluetooth), which for me would be an absolute win on its own.

 

[Tecnodave]

Not slightly better, way better, they both do the same thing, neither is for balancing cells, they are for monitoring the whole system, the batteries, the inverter, the charge controllers and all other loads both in and out of the battery

The BMS is only concerned with the battery it is monitoring


DISCLOSURE.......Bogart is a neighbor, we have discussed many issues, I have used his monitors for many years both on my fishing boat and on my solar system. I have only used Victron Smart Shunt in customers systems so I do have first hand experience with both products. Just because we both live on the same mountain does not mean that I view his system as better, its first hand with both systems.

Now can we bury this and focus on getting Tommy’s system stable so he can enjoy his boat before he is redeployed in active duty

 

[Short_Shot]

Yeah, but now I'm on trying to justify why he should spend even more money to replace something he already has that does "the same thing".

>says it's way better.
>can't seem to post specifics.

Why is it so much better that it would solve any of OP's problems and be worth the added cost of replacing something he already has?

Does he need the improved data?

Does anyone *need* that?

If I had neither, I'd probably pick the one you suggested simply for the wifi. The data logging would be a nice benefit.

At the end of the day though the only thing most people need is %soc and perhaps to check wattage in/out at a glance. The victron has its failures for sure, but it's already paid for.

 

[Tecnodave]

@TommyHolly

Yes i very much approve of your current plan, this is much better having 4 batteries 3P4S than 16 cells in parallel.
As I said when we were talking about your 12 volt batteries in parallel , there is a limit on the number of cells or batteries connected in parallel. three is good, 4 is iffy, more then that you get the problem that i described in my first post of the different resistance in each battery wire. That is what I was trying to forcus on. Making the FLA batteries more stable so you have more time to work out the issues going back to LFP. I do know the need for redundant systems when sailing as i have a few years sailing on a Brown Trimaran, much smaller than your cat, but still no radios, no GPS out there in the middle of big seas.....scary as chit....Im sure that you have seen some big water as well. I have only sailed the Pacific..

 

[Tecnodave]

@Short_Shot

Tommy Holly has already decided that he will not replace the Victron......

Let it go, there are better things to deal with