ABMS/2Q firmware with additional CAN messages

• t

  tine

  2/6/25, 3:44 AM

  I am opening this topic, because a client requested cell voltage data on the CAN bus for Victron. Since this is not supported in the original Victron GX protocol, NodeRED  should be used and a custom add-on should be created for the extra CAN IDs and GUI. How many users would like to have this additional feature? If we make this firmware will you be prepared to share the software? We have to make this applicable for ABMS with 4 cess and up to 8 tmep sensors and 2Q with 16 cells and up to 8 temp sensors first and then extend it to Master-Slave System. Should this be in the Victron firmware by default or enabled by another instruction?

  Let me know, please.

   

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• B

  Pro user

  Ben

  2/6/25, 4:03 AM

  I have the feeling that most of my customers don't need to see all cell voltages.

  What the Cerbo shows at the moment is the lowest and highest cell.

  This is for me good enough.

  I put alarm on highest and lowest cell in VRM.

   

  

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• o

  o-firstname

  2/6/25, 10:09 AM

  I was the customer that requested this feature be enabled and @Ben   it's not something that anyone "needs" but is a "feature" that some would benefit from. There are several use cases most importantly tracking the health of all cells over a longer period of time and detecting issues with these home made battery packs. In the screen shot below you can see a Grafana graph I built that shows detailed battery info to aid in the tracking of overall battery health and to dial in charging parameters. In one of the screen shots you can see a run away cell that I had due a poor top balance and I was able to catch the issue. 

  Again this isn’t something that is “needed” for the BMS to do it’s job but is an extra feature that could be a selling point to some customers and could widen the sales base for REC. If you web search this topic there are several people from several forums including this one asking about it. 

  The only reason I asked for the data to be included with the data being sent to the VenusOS device is that VenusOS comes with a MQTT server installed by default and is setup to advertise all the published DBUS values as topics via MQTT and is a simple way to scrape this data.
  
  REC has the WiFi module which might be another solution, if the WiFi could include a MQTT server this would also satisfy the objective. I haven’t opened my WiFi module so I’m not sure what the specs or architecture are to know if it could support that overhead. Yet another idea would be to use an API on the WiFi module to just open the data up via web sockets and allow the client to take it from there. 

  Acknowledging that this isn’t a feature for everyone I do think there is merit in adding it to the product. Victron being the prime example of adding a MQTT server when one was not “needed” has opened that platform up for users to create all kind of fun and useful things to act as companion pieces and their willingness to allow customers to interact with their product at a software level was a big deciding factor on why I went fully Victron (except their batteries)

  These graphs were used when I was using a cheap MOSFET based BMS and a wonderful piece of software that added it to VenusOS as a serial BMS. If JKBMS or one of the other Chinese brands made a contactor based BMS I would probably still be using it but my needs brought me to REC which is a great product. 

   

  

  

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• o

  o-firstname

  2/6/25, 10:33 AM

  @tine  
  
  

  I am opening this topic, because a client requested cell voltage data on the CAN bus for Victron. Since this is not supported in the original Victron GX protocol, NodeRED  should be used and a custom add-on should be created for the extra CAN IDs and GUI. How many users would like to have this additional feature? If we make this firmware will you be prepared to share the software? We have to make this applicable for ABMS with 4 cess and up to 8 tmep sensors and 2Q with 16 cells and up to 8 temp sensors first and then extend it to Master-Slave System. Should this be in the Victron firmware by default or enabled by another instruction?

  Let me know, please.
  
  
  

  Speaking about the requirement for Node-Red to be used. There is no specfic requirement for Node-Red to be used. The end user can get the data off the Venus device with any MQTT client. I didn't even use Node-Red to create those graphs, I was pulling the data with a MQTT client into a raspberryPI and then using it from there. If you're requiring a trade to implament this I will be happy to share my Grafana graph and write some detailed instructions for your cutomers to use to emulate what I have done. 

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• B

  Pro user

  Ben

  2/6/25, 10:30 PM

   In VRM the widget I reviewed the most, is min/max cell voltage.

  Which means, I agree that monitoring cell voltage is very useful, to see how a system behave.

  What is missing in VRM to monitor ALL cells.

  The Cerbo shows already which cell is the lowest, but not visible in VRM.

   

  Instead of creating something "new", I think Victron needs to be asked to "accept" all cell voltage data through CAN, and show them in GX and on VRM. 

  Probably they need to extend some of their data protocols to make "space" for this.

  Show them in VRM in a selectable widget, 12 V system, one widget cell 1 to 4,   24V system, 2 widgets, cell 1 to 4, next widget, cell 5-8. etc for 48V.

  Keep the min/max widget also.

   

  Victron often develops things that are first usable for their own product/batteries.

  But this function is also better for monitoring their own batteries, which means they are probably willing to do so.

   

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