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squelch avatar image

Using BYD batteries with 3 parallel MultiPlus and VE.Can MPPTs

Hi support,


Hope you can help me on my below inquiry.


We now have an ongoing commissioning of our 16.5kWp 15kVa 27.5kWH system, below are the list of components we used:
a) Multiplus 48/5000/70 : 3 units
b) Bluesolar CC MPPT 150/85 (VE Can port) : 4 units
c) BYD B-Box L 2.5 : 11 units
d) CCGX : 1 unit

Upon reading the notes/references/guidelines from Victron site, i have some clarifications on our installation. I've listed below my 1 set of inquiries:

1) With VE.Can MPPT, CCGX can only communicate either from MPPT or BYD BMU? and on my current setup i just prioritize the connection of BYD to CCGX (VECan port).

2) Do i need to wire for Allow to charge and allow to discharge from BYD to Inverter/charger (not familiar on the setup) can you assist me on this ? do i still to add an assistant aside from ESS? so that the BMU has a control on charging and discharging coming from the MPPT.

3) After paralleling the 3 Multis ( using VE bus quick configure), after turning the BYD batteries the system won't start up. But if the inverters were not connected in parallel , system is up and running. Beeping alarm on the BMU 4X see attached screenshot.


Ty



BYD
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9 Answers
BYD_service avatar image

Thank you Rob and Boekel for sharing the information.

Regarding point 3, sometimes the inverter capacitance is too high so it makes the batteries think there is a short circuit.

The correct startup sequence is as follows:

-With the batteries isolated from the inverters, switch them all on (just switching one on would be enough to start the rest)

-Connect the inverters one by one

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Hi BYD Service,

Thank you for the response, i'll try what you have suggested as the batteries works fine on the individual basis.

  • I'll keep you posted.

@BYD_Service, it works successfully. I was able to energize it.

BYD_Service,

Is there an app that i need to access the BMU interface?

We are now using B-Box 2.5x11 units with fw 4.17.

Is it the latest fw version?

Sorry I didn't get a notification for this message. You need a piece of software and a USB to RS485 converter if you want to update to 4.22.

You can email me at a.garcia@eft-systems.de

Hi, I would like to update my BYD B-Box Batteries as well how can I update it?

Rob Duthie avatar image

Hi

Have you logon on using the BYD software via there RS45 port, as that tell you a lot of information about the SOC and cell voltages etc.

And you have updated the BYD firmware to the latest?

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I haven't tried and unaware of BYD software. Is it on their website?

Yes and no i got from a dealer, here is the web site go to the down load section

and you will see all the different files for all the models, and instuctions on how to connect etc using the the RJ45 socket.

http://alpspower.com.au/download/

squelch avatar image

Hi BYD_Service & Victron,

I've attached two pictures below, from MulTI & BYD SOC. I don't understand that why my BYD SOC value was stuck until this day. Multi is 86% & BYD 96% still. I think it happened when the system reaches 96% and the BYD was already stuck.

Any luck that i could do on my setup?



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Squelch,

This has already been answered for you.

PLEASE read the BYD Victron Manual in its entirety:

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

squelch avatar image

Moreover,

1) Why is it that CCGX won't detect the discharge load and current on the from the BYD BMU? and the SOC is still stuck on the 96% since yesterday afternoon. Charge controller is still off by the way as i havr not yet the wirings ofAllow to Charge setup. Selected battery monitor is BYD BMU.

Already tried to degrade and re upgrade the FW of CCGX.



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Depending on the size of the load, this might addressed in the known issues and limitations section of the BYD Victron Manual. There is a high minimum threshold for the BYD amp meter.


squelch avatar image squelch Guy Stewart (Victron Community Manager) ♦♦ ·

@ Guy, may i need your assistance on my previous inquiry about the wiring setup of the allow to charge between MPPT and BYD? Im afraid that it might have a harmful effect on BYD batteries w/out the control.

It is a safety feature, so it is possible to TEMPORARY charge normally based on the voltage parameters without the allow to charge contacts.

It is an on/off connection. You can connect all those terminals in series with the BMU terminals, if the connection closes, they should all get the message.

Remember this is just friendly free advice. I am certain that BYD insists in their warranty document that installation must be done by a trained service technician.

I have not tested that configuration myself.

squelch avatar image squelch Guy Stewart (Victron Community Manager) ♦♦ ·

Thank you, Guy.

So, i don't have to worry if my system is overcharging the battery when in fact the only equipments connected on my ccgx are the BYD BMS and Multis?

I'll just sent a note to BYD pepz on my other concern then.

Rob Duthie avatar image

Hi

A basic precharger circuit, which i have used on UPS for testing after repair etc, they range from 48vdc systems to 240vDC, there is not sparking or inrush at all. If not used there is always a flash when connection up batteries etc. ( makes you jump).

DC Precharger Circuit-Bypass Circuit.pdf


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Thank you, Rob.

So i have to install 3 of this? because i have 3 paralleled banks or just on the 1 bank?

Just installing on one battery bank to pre charge all the inverters will do it.

Just remember to have a MCB or circuit breaker for each bank and turn on in sequence.

Starting with the first one with the precharger first.

Ok noted.

I have an isolation cb per bank. Ill review the materials needed and sourced out locally.

Ty

squelch avatar image

@ Victron support:

Do i need to wire for the Allow to charge contact on my setup? Based on my system diagram (i'm using VECan MPPT)?

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Yes, you need the allow to charge wire to the VECan MPPT.

You do not need any assistants for the Multiplus though. It’s charge and discharge control is done through the the CANbus and DVCC.

squelch avatar image squelch Guy Stewart (Victron Community Manager) ♦♦ ·

Hi Guy,

Any guide you can give me as reference?

Or schematic diagram, maybe.

squelch avatar image squelch Guy Stewart (Victron Community Manager) ♦♦ ·

Hi Guy,

Can you help me on how to setup the Allow to charge configuration using the below attachment. Your help is much appreciated.


vecan-mppt-bmu.jpg (50.4 KiB)

Did you read the manuals for the MPPT's and the batteries?

Rob Duthie avatar image

Hi

Another thing would have to have a resistor pre charger on the battery circuit supplying the inverters, as they do for electric cars and UPS and large inverters with high voltage batteries etc.

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  1. Hi Rob, does Victron have that resistor kit thing? Or do you have any equivalent schematic diagram i'll try to look for the materials.

Hi

No i don't have a kit. I will send you a schematic on how to wire using a standard contractor etc, these are off the shelf parts etc.

Thank you, Rob.

Btw, maybe you are also familiar on my recent remaining inquiry about the Allow to discharge setup configuration?

Hi

No, explain what is required to discharge what?

For i know, BMS should have a control on the charging to stop/float the charging process when max cell voltage increases above threshold.

Boekel avatar image
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Rob Duthie avatar image

Hi TY

Codes for alarms

https://mp.weixin.qq.com/s/mEhDOryYX-3qaSNiLW_sIQ


Regards

Rob Duthie

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