Configure Cerbo GX relay based on BMS-CAN battery temperature

[ldenisey (Lucien)]

Hello,

I would like to trigger a relay of my Cerbo GX based on battery temperature for battery heating.

I get the temperature from a third party BMS (Daly BMS) which is connected to the cerbo via CAN port as described here.

The connection works well, I have the temperature :

I have read the cerbo documentation. I set Settings → Relay → Function (Relay 1) to temperature, I see the Temperature control rules menu :

But the menu shows nothing :

Sorry if I have missed the obvious but why ?
Is the battery temperature information not considered as a valid temperature sensor ?

Thanks for your help,
Lucien

[pwfarnell]

This came up a few days ago for an alternator temperature supplied via a secondary source via VE CAN.

It appears that temperatures from secondary sources do not show up as temperature sources for the relay function, so WS500 or Mopeka level sensors or Daly BMS etc. I do not know why this is the case, but only primary sources such as directly connected temp sensors or Ruuvi tags work.

I am not sure if this value appears in Node Red Battery node or the Custom Input node. I know that the Mopeka level sensor temperature can be accessed this way. You could look on Node Red and if so program the heater this way.

[ldenisey (Lucien)]

Thank you for your answer, it confirms that this behavior is to be expected.
Strange behavior though, does anyone know if there is a reason for this or if it is just a bug / unconsidered functionality ?

I confirm battery temperature is accessible in node red using a “Battery monitor” node. I am following this path as a work-around for now.