A battery measurement

[jenya7]

I'm planning to power my ESP32 board directly from a battery. How can I measure the state of the battery to alert a user on low battery?

May I apply VCC directly to an analog input to measure the battery voltage?

[Sprite]

That depends on the battery, but generally, no. You need a voltage divider to bring the voltage in range of the ADC.

[jenya7]

That depends on the battery, but generally, no. You need a voltage divider to bring the voltage in range of the ADC.

It will be 1.8v?