Any update on this? Having the same issue
The Google Assistant Integration page does say that sensor domain is supported and I am able to add a temperature and humidity sensor created by a device and google assistant tells their value when asked.
I have a template sensor in home assistant that I am not able to get into google assistant.
Any ideas?
Regards,
Vaibhav
Make sure tou set a device class
Were you able to expose template sensors to google assistant?
I just tested a few device classes with my template sensor. Temperature and humidity device classes work for my template sensor. My sensor has nothing to do with temperature or humidity, but I set it only for testing.
I tried battery, date, power. None of them worked.
On Google Assistant Integration page, for sensor domain, it only says - * sensor (temperature setting for temperature sensors and humidity setting for humidity sensors).
So may be only temperature and humidity sensors are supported?
Regards,
Vaibhav
These are the sensors that are supported by Google Home:
But yes, maybe only temperature and humidity sensors are actually supported on the Home Assistant side. What kind of sensor is your template sensor? What device_class did you give this sensor (As @DavidFW1960 already said): Sensor - Home Assistant (home-assistant.io)
In any case, you cannot expect any generic template sensor to be supported by “Home Assistant → Google Assistant”.
The list on the Google developers link does not contain temperature and humidity sensors but those are supported by HA → GA. Are you sure that is a complete list?
I tried a few device classes but currently no device_class is set for my template sensor.
My previous reply 
I am sure hoping that someone can implement this or come up with a workaround.
So just to bring up another “sensor” type that is supported. If you have a window/door open/close contact sensor that will also work. I have 3 sensors on some doors and I was able to expose those to Google Assistant and I am able to ask Google Assistant if one of those doors is open or closed and it responds with the correct state.
What device class is your window/door sensor ?
Hi, is there a workaround to add a battery sensor to GA? i want to ask GA how much the car is charged
thnx