That’s exactly right!!! Thank you @tom_l!!!
I did it on my esp_2 and it works!
Here is the final portion of that yaml:
- platform: adc
pin: VCC
id: "VCC"
internal: true
- platform: template
name: "esp.2.battery_level"
unit_of_measurement: '%'
update_interval: 5s
lambda: |-
return ((id(VCC).state /3.30) * 100.00);
Thank you!!!