Tado TRV Battery - Gauge Card


I use Tado and the TRV for the battery does not report a numeric value. It’s either reports Normal or Low. Now in an older dash I was using the battery card and had the below set.

I am looking to use the Gauge card to display all my batter levels. this is easy for everything thats not Tado. I think using a template may work but I am unsure of the syntax. Can help one help? Thanks in advance

-entity: binary_sensor.va3886818048_battery_state
    name: Dining Room Thermometer
      - from: 'off'
        to: 100
      - from: 'on'
        to: 25