question

Alistair Warburton avatar image

VEConfigure SOC setting for BYD 13.8

Noob here... worried I have not got things set up properly.

Easysolar 5000, BYD 13.8

I am confused RE SOC instrumentation....

Supplier, Wind & Sun, say if I want to use DC I will need a battery monitor, which if the SOC is coming from the Multiplus make sense, but if the BYD box is providing SOC, which is how I have it configured now, then I dont understand why this would be the case.

Not suggesting they are wrong but would like to understand...

Part two of this question is about VEConfigure settings.

At least one of the manuals I have seen, sorry no idea which, there are so many but a BYD one I think, states that the SOC option should be ON when selecting Lithium from he general tab, however I cant work out what settings to apply if I set this and I thought that the B-Box was controlling things anyway... Suggestions?

I need educating and any help would be appriciated.

MultiPlus Quattro Inverter ChargerSOCBYD
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6 Answers
Daniël Boekel (Victron Energy Staff) avatar image

Hi @Alistair Warburton

ok:

" If I add a DC load do I NEED a battery monitor and if so WHY? "

No, (the battery is the battery monitor) but you might need a protection device between the battery and the DC-load, that's why I asked 'what kind of load'


" Should SOC be on for Lithium in VEConfigure or not? "

Yes

" I cant find the AH rating for the 13.8 in any of the linked documents "

Finding the AH is very simple: devide the battery Capacity (13.8kWh) by the nominal voltage (51.2V) and you get the Ah rating: 270 Ah

But in the end, when you are using the CANbus connection to a GX device, it doesn't matter, the batteries SOC will be sent to and used in the Multi / Quattro


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Thank you, that is helpful,

My issue isnt understanding the electric principles it is making sure that I am doing what I should.

Your comments re AH rating make perfect sense but that isnt what the manual was telling me and I was just looking for clarification... which I now have.

The same is true of the DC load... I had assumed, as you state, that the combination of BYD BMU/BMS was handling the SOC measurement and battery protection. However My supplier, Wind And Sun, told me that if I added a DC load the SOC would be incorrect because the chargers, MPPT and or Multi, would see DC current to my load as charge current. This didnt make much sense, if the BYD unit was doing the measuring,hence the qauestion.

Again the clarification is much appriciated and the answer what I anticipated it would be.

DC protection... Absoluetly, I had just taken that as read, sorry I wasnt more specific and I understand and appriciate your need to point it out.

If I add a DC load, and set the system as having one, will the CCGX use the BYD data to calculate and display the DC load state?

(I am assuming it will)

Please accept my appologies for letting my frustration show.

I am extreemly impressed with th system thus far, my expectations were high and it has exceed them by some margine.

I think perhaps, as a controls engineer, I am struggling with the lack of detail. I am not saying that anything isnt working, just that there is a Black-Box air about elements of it that I cant find answers to.

If you could clarify one last point, I would be very greatful..

Will the BYD ststem, BMU/BMS, throttle both chargers in the event that the battery is too cold to accept a charge, or the charge current needs to be significantly reduced.?

Is there anything I should/can set to make this happen and or back-stop the control strategy?

I am assuming this will just work but would like to be sure. I do not plan to run the sytem cold and will be installing insulation, and ventilation, to help, but I want the control system to be the primery protection, not my fiddlings.

Thanks and regards,

Al

Yes the system can calculate DC loads, but this will be very coarse, because of the slow update frequency of the BYD's current values.

you didn't answer what DC loads you're planning to add.


Yes the BMS will lower the Charge Current Limit (CCL) based on temperature, and the Victron system will listen to this.


If the system doesn't listen to the battery, and go past the limits, the battery will disconnect from the system to protect itself.



If you want to know the insides of the system, you'll have to read about all the options and functions described in the manual, you'll find answers to just about everything.

Alistair Warburton avatar image

" If I add a DC load do I NEED a battery monitor and if so WHY? "

How can I clarify this any further?


" Should SOC be on for Lithium in VEConfigure or not? "

and if it should...

" I cant find the AH rating for the 13.8 in any of the linked documents "

The BYD document tells me to set this, how if I dont know it?

I dont know how to be any more clear.


All I am asking for is somone to tell me, for this combination of kit, what the settings, relating to battery monitoring and charging, should be.


As I said earlier, are you asking me to go through the software and ask individually what everything does and what setting to use? Surly not!

This is supposed to be a supported, in fact recommended, solution...

Why can you not simply give me a list of settings that I am supposed to be using with an absolutly standard setup?

Why can you not tell me how it works, or better still point me to a document that does that?

I could at least then work out what I do or dont need to worry about, settings wise!

Before you ask, yes I have read the help, and I am pretty sure I understand the concepts.

However, when looking at help I cant see anything that tells me to 'ignore this setting when using BYD". In that respect Help isnt much help because it contradicts the BYD document.

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Daniël Boekel (Victron Energy Staff) avatar image

Hi @Alistair Warburton

I'm sorry but your posts are very difficult to read, can you tell us what information / settings you are missing in the Victron/BYD document?
(you write you are asking 3 questions, what are these questions?)


https://www.victronenergy.com/live/battery_compatibility:byd_b-box


Also you are talking about DC-loads, what kind of loads are you planning to connect?

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Alistair Warburton avatar image

Section 4 describes just 8 settings, one of which requires a value not supplied for the 13.8 battery

I cant find the AH rating for the 13.8 in any of the linked documents I can see how to calculate based on the number of cells but then I cant find the number of cells either!

My point is that this stuff is probably important, so I have read what I could about configuring my system within VEConfigure. The issue is that there dosnt seem to be a document that tells me what the system, as a whole, is/should be doing in any given circumstance.

The compatibility document tells me that a couple of things are ignored when using a BYD system, which is just fine, but it dost say what replaces this funcionality, or what, if anything, this impacts in a wider context.

I am trawling through multiple documents from two different manufacturers none of which appear to contain a complete overview...

The whole processis making me uncomfortable... If I get this stuff wrong, because I am guessing and get something wrong, I could easily dammage the battery and pottentally some of the other kit.

I can see that there is a plug and play aspect, which is good but there are obviously settings that need to be manually configured and these are far from clear.

Are you asking me to go through the entire system and list everything, that looks relavant, which I am unsure about?

Or are you telling me that nothing other than the few settings described can affect the battery?

To be fair I think both of those options are extreme and unrealistic but that leaves us with me needing to take some responcibility for my configuration.

To do that I need to know what it attempting to achieve, how, and what settings influence the various bits of that algorythme/system.

Just to be clear I havent even got to the MPPT settings yet. I know the BYD is going to alter the output of the solar charger and I also know I have to configure the unit...

Which document is that info in? How is this interaction achived? how will I know if it is working as it should? what will happen if something fails?

All I know now is that stuff is supposed to happen and that the CCGX is the gateway that facillitates the interaction of the two, possibly more, bits of kit. I dont think that is sufficiant info for me to determine that all is well and working as it should.


Sorry, geting a little frustrated...

This is a huge investeent for me and I am simply not comfortable hoping it is OK.

If it was all plug and play then it would be fine and I wouldnt be messing with it.

However it isnt, I am being instructed to set/configure things. I dont view having to alter settings as an issue, the issue is not being able to find information with respect to what the settings should be and how they affect the system.

Perhaps I am missing something, some doc that describes this stuff, sorry if I am, but the one you linked, even in conjunction with other Victron/BYD docs, just isnt answering these questions.

Al

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Alistair Warburton avatar image

Yep... Read and understood that.

I have to say there are some bits missing, or perhaps simply not adequatly explained, but it is working as described, even I the mechanisem isnt properly explained.


Questions... I will try again.

I am getting SOC from the BYD system as described, mostly, in the doc that was linked above.

I am assuming therefore the multiplus is not supplying this data and and that any DC load applied to the bus would be measured.

My supplier said that a DC load would be treated as charge current, when charging and not measured when discharging, when the SOC was being calculated by the multiplus.

This makes sense as dose the recomendation to use a battery monitor to fix the issue...

At least it would if SOC wasnt being measured by the BYD unit which will of course see the actual battery current, no matter where the load is. And yes I apriciate the 1A threshold and its implications and potential workarounds.

SO...

If I add a DC load do I NEED a battery monitor and if so WHY?

I am not sure how I can clarify question two any further...

Should SOC be on for Lithium in VEConfigure or not?

At least one document suggests it should but dosnt give the required settings.

However with if SOC is coming from the BYD kit I dont see how/why this will help and I suspect it could actully hurt.


I have to say, given that I have just been pushed to use an expensive, no matter how good, supported battery, I was expecting, at the very least, a definitive setup guide.

Death by 1000 docs wsnt on my radar! If this stuff is well defined and supported why isnt there a setup file?


Dont get me wrong I am very impressed with both quality and performance, even this early in my journy, but setup can/should be so much easier.

I build hydroelectric control systems for a living so I am very comfortable with the concepts in play but the required information is spread throughout many, some conflicting, documents, which is just ODD. Add to this the fact that there is no, that I have found, information on the underlying algorythms and you have a recipe for confusion.

IE... Where dos it say to ignore/hide battery info from the muliplus.

Again I am not saying this info isnt available, just that I havent seen/found it and and this sort of omission is exactly why I am asking questions.

I am pretty blaze', in general, about instructions but having just spen circa 11.5k on this kit and being well aware that a bad setting could, at best, break it an at worst, break it whilst invalidating the guarantee I really want to get this stuff right.


Am I asking too much?

My supplier told me I couldnt use a home growm power wall, which puts the onus to get things right on me, and then sent me multiple documents, none of which are, singlarly, definitive, when attempting to tell me how to set up the 'supported' solution.


Right now I am asking 2 questions, 3 if you count the other thread, but I suspect there will be many more based on the hours I have spent not finding answers thus far...


This stuff looks lake Great kit and I wat to keep it that way by operating it he best way possible.


Slightly frustrated...

Al

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BYD_service avatar image

Hello Alistair,

I'm sorry the questions are not too clear to me. The main manual to look at configuration and also when to use a battery monitor instead of the internal BMS monitor is here. https://www.victronenergy.com/live/battery_compatibility:byd_b-box


Could you take a look and let us know, in which way how does your case not match the options offered there?

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