Warning: drivers.thermostat is missing an array 'energy.batteries' because the capability measure_battery is being used. Specifying the type of battery will be required in the future.
According to the docs the thermostats (DECT-300 & DECT-301 are the only ones?) use 2xAA's.
When building got an error:
According to the docs the thermostats (DECT-300 & DECT-301 are the only ones?) use 2xAA's.