How to read BMS/Multiplus values using API, ModbusTCP or MQTT

Modifications
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1

I use VRM API, ModbusTCP and MQTT.

I would like to read:

  • Multiplus settings, such as Absorption voltage or Float voltage
  • Battery/BMS statistical values, such as min/max cell voltage (which is available in the VRM as a Widget)

Regarding Multiplus settings; I want to read the values remotely (no MK3 cable) to investigate a system whether settings are correct and/or inadvertently changed. This would save a site-visit.

Regarding Battery/BMS, I can get the battery voltage and SOC, using the VRM-API/stats with attributes bv and bs, but I cannot find the correct attributes for min/max cell voltage. The closest I find (VRM-API/attributes) are 173/mcV for Minimum cell voltage and 174/McV for Maximum cell voltage, but the VRM stats-API does not return information.

Suggestions more than welcome!

2

These are mostly all available from the GX via MQTT.
Go download the modbus register from the victron git page, just google it.
Nodered is also a preferred way of doing this - refer to the dedicated nodered section in this forum.

The multiplus basic settings and assistants are typically only configurable via a mk3 or remote veconfigure.

3

Yes, I did find the register (CCGX-Modbus-TCP-register-list-3.71.xlsx) but did not find the Absorption/float values.

Using MQ Explorer I did not find those settings either.

If you know the register values, please let me know.

4

I don’t believe the internal settings can be accessed like that.

5

Thanks