Question: Battery temperature

[zejulio]

Hello,

I saw on the docs 33096 is the lead-acid battery temperature, on my inverter I got 63535, I believe this is means it does not provide this value.
I wanted my battery pack temperature, does anyone know is it's available and how to access it?
I know that the battery has this information on CAN...

Thanks.

JS

[philpem]

Do you have the external temperature sensor, and is it attached to the battery?

The data on the canbus is provided by the battery's BMS and you're probably better bringing that into HA rather than relying on the inverter pulling it off the canbus and presenting it on the Modbus.

[zejulio]

I have the CAN protocol for my Battery BMS, and I know it sends there the temperature, I thought inverter would have this information to know if it's overheating and lower the charge current, but I dig everywere I only found one register for battery temperature (33096 "Lead-acid battery temperature") and it's not working, maybe is for other use.

I also was thinking of doing something with ESPHome to get the CAN data directly to HA, but I think it's a over engineer just to get the battery temperature :), if the inverter send it on modbus it was a clean solution.

[philpem]

The Lead Acid Battery Temperature modbus value is for when the inverter is configured for lead-acid batteries and has the optional lead-acid battery temperature sensor connected. I've never found anyone selling that thing.

Your best bet is to see if your BMS has RS485/RS422 or Bluetooth and use that. For instance the JK and Seplos BMSes have 485/422 and the newer ones have Bluetooth. Drivers are available for Home Assistant to access them, using an ESP32 as a Bluetooth proxy.

[zejulio]

I see. Did not knew that there was a temperature sensor extra.

As yold my battery uses CAN to comunicate with the inverter. I will do an esphome can device to get the information directly from the battery.