Would be great to include some kind of battery voltage monitor on XIAO esp32c3 board. It seems there are some not used GPIOs which may be used to switch on some voltage divider and route the middle to ADC (GPIO0+1?). Don’t know exactly because I’m missing the schematic. Second is to have an indicator if the device is usb powered or on battery. Maybe there is another unused GPIO we can use for this without using D0-D10 (GPIO11?). Or the enable battery voltage measurement pin may be used as input to get this info because the measurement circuit can be externally enabled in case of usb powered.
I agree! The ESP32S has 6 ADCs and there are only 4 exposed (the ones attached to GPIO0 and GPIO1 are not exposed.) I have a battery connected and am doing a test reading those ADCs but I can’t tell for sure if they are correlated with the battery voltage. Hopefully Seeedstudio will come out and let us know! If I get desperate I may crack the metal cover off and go investigate myself 
Totally agree. XIAO cannot do such nice items and not integrate a voltage reading solution, this is crazy.