Homematic thermostat HM-CC-RT-DN battery status

How can I read the Battery status in Homeassistant?

The HM-CC-RT-DN has on Channel: 4 the “[BATTERY_STATE]: 0e” and on Channel: 0 the “[LOWBAT]: 00” value.

How could I display these values in HA?

You have to create a template sensor. It’s explained in the HomeMatic documentation here.

Daniel thank you for the Info. Can you please give me a hint how to use the templete sensor?

Here it is not working how it should be. :frowning:

It’s just like the example in the documentation. You just have to replace the entity ID (it’s there 2 times) with the one of your climate entity, and replace the Valve with battery. Once you have done that and restarted Home Assistant, you should have a new sensor entity in Home Assistant that has the battery level as its value. This extra entity then can be used for automations.

@Tom74, did you get it to work? Would you share your Config? I tried it with this in my configuration.yaml, but it does not work:

  - platform: template
        value_template: '{{ state_attr('climate.000313c999f2f8', 'battery') }}'
        entity_id: climate.000313c999f2f8
        friendly_name: 'Kinderzimmer Raumthermostat'

Sorry, for the delay. I had some problems with hassio on my docker installation.

So I moved back to pure homeassistant installation on my raspberry pi.

My config looks like this:


- platform: template
          unit_of_measurement: "V"
          icon_template: mdi:battery
          value_template: '{{ states.climate.heizung_schlafzimmer.attributes.battery}}'
          entity_id: climate.heizung_schlafzimmer
          friendly_name: 'Heizung Schlafzimmer Batterie'
          unit_of_measurement: "V"
          icon_template: mdi:battery
          value_template: '{{ states.climate.heizung_bad.attributes.battery }}'
          entity_id: climate.heizung_bad
          friendly_name: 'Heizung Bad Batterie'
          unit_of_measurement: "V"
          icon_template: mdi:battery
          value_template: '{{ states.climate.heizung_wohnzimmer.attributes.battery }}'
          entity_id: climate.heizung_wohnzimmer
          friendly_name: 'Heizung Wohnzimmer Batterie'
          unit_of_measurement: "V"
          icon_template: mdi:battery
          value_template: '{{ states.climate.wt_heizung_wohnzimmer.attributes.battery }}'
          entity_id: climate.wt_heizung_wohnzimmer
          friendly_name: 'Heizung WT Wohnzimmer Batterie'
          unit_of_measurement: "V"
          icon_template: mdi:battery
          value_template: '{{ states.climate.heizung_kuche.attributes.battery }}'
          entity_id: climate.heizung_kuche
          friendly_name: 'Heizung Küche Batterie'


id: battery
title: Batterie
icon: mdi:battery
  - type: "custom:monster-card"
    show_empty: false
      type: entities
      title: Thermostate
        - entity_id: sensor.heizung_*_battery


what values can this get?
I want to do a batterie page with other devices like Shellys, so a % value would be nice.

I solved it this way but only works in conjunction with CCU and not with access point. Create a template sensor for each device. It may be that you first have to release the sensor when integrating the devices in HA.


I think your voltage values are then between 3V and 2.1V…
But i read my voltage value from HmIp SWDOs (Fensterkontakt), i currently get between 1.1V - 1.3V ?

My Heating Sensors (EVO) or my wall-thermostats (Heizkörperthermostate), Buttons (Taster) are also in range 2.1 - 3V.

You also have some window sensors there… do u know why is it like this showing 1.1V ?

Edit: Ok, that was my bad :slight_smile: 1 Battery vs. 2 Batteries
But now i have another question…

So the scale with 2 batteries is between 3V - 2.1V. (where 2.1V means 0%):
3V 100%
2.9V 89%
2.8V 78%
2.7V 67%
2.6V 56%
2.5V 44%
2.4V 33% —> default LOW BATTERY Threshold (in CCU)
2.3V 22%
2.2V 11%
2.1V 0%

I cannot convert your formula for 1 Battery (1.5V)
1.5V 100%
1.45V 89%
1.4V 78%
1.35V 67%
1.30V 56%
1.25V 44%
1.20V 33% (default LOW BATTERY Threshold for 2 Batteries)
1.15V 22%
1.10V 11% —> default LOW BATTERY Threshold 1.1V
1.05V 0%

Now I have a SWDO, which shows me 1V and Low Battery… it does not match the above scale…

maybe it is like this?:

1.5V 100%
1.4V 83%
1.3V 67%
1.2V 50%
1.1V 33%
1.0V 17%
0.9V 0%

So the formula is: ((voltage - 0.9) / (1.5 - 0.9) * 100) ?
Do you also use like this?