Dear Community,
I do have an old VE-BUS BMS (the black one) with this wiring diagram:
I think that the BMS is not working properly, so I want to replace is with a new one. As I don´t want to change any wiring, if this is possible, I am not quite sure which of the newer BMS would be the best choice.
From my understanding the VE.Bus BMS V2 would be the best choice.
Could you confirm this?
Thank you very much for your help...
...kind regards,
Daniel
You can not use the small BMS as it does not interface with the inverter.
The Lynx BNS is more capable but will need major rewiring of the power cabling plus the control wiring.
I would go for the VE Bus BMS V2, you will need some minor control wiring changes and may need to fit the mains detector depending on your inverter model, details in the manual.
What is going wrong with your current BMS.
Thanks @pwfarnell for the quick response! That´s what I thought also, that the VE BMS V2 fits best.
The problem with my BMS is, that it´s not cutting of loading. It´s possible that the relais (Cyrix LI Charge) is broken or the BMS. I don´t think, that the Cyrix is out of order, so I thought it would be reasonable to change the BMS.
I can´t figure out why the charging is not disconnected. Tried several things and also posted a question here in the forum, but didn´t narrow down the issue more closely...If you have any advice, I´d be more than happy about it...
I missed your original question. Some of the answers talked about DVCC. However, the V1 BMS does not do any comms to the GX or control through DVCC, the the comparison with the V2 BMS at the following link.
https://www.victronenergy.com/media/pg/VE.Bus_BMS_V2/en/appendix.html
The V2 BMS will be better as this tells the MPPT via DVCC to stop charging before getting to over charge warning. You might change anyway as this is a significant advantage.
In.your trouble shooting of the current problem I would do 2 things.
1. Remove the control wire from the Cyrix but then measure the voltage on the MPPT and battery side terminals to chevk that they are different and the relay is disonnecting.
2. When the unit is running normally measure the voltage betwen the ATC terminal on the BMS, this should be 12V. Then wait for the over charge warning and then measure the ATC terminal voltage again, it should be very low, 0V or close.
These 2 checks should confirm if the BMS and Cyrix are working.
@pwfarnell : I now had the chance to go through your testing options, written above.
1. I disconnected the control wire form the Cyrix. The relais makes the typical "noise" like disonnecting, so mechanically it´s working. But the voltage is the same, on both terminals.
Question: what could be the cause for that?
2. I also waited for "overcharging", but the voltage didn´t drop.
Can you interpret these phenomena's somehow?
I think it´s possible, that I misconfigured something due to a firmware Update of my devices, with new functionalities VICTRON implemented. But I can´t figure out if it´s a broken device or something configured wrong...or both.
Next test is if you have a multimeter that measures ohms/ resistance. Disconnect the Cyrix from the battery and the mppt and the signal wire. Measure the resistance, it should be very high or infinite, if it is only a fraction of an ohm or zero then the cyrix has failed.
Not sure what else could be the problem.
Thanks for the answer, I will check the resistance these days.
Don´t think that the relay is broken, but it could be...
...thanks for the advice!
