Voltage Adjustment - qba667/FlySkyI6 GitHub Wiki
Voltage Adjustment
If you find your voltage sensors measurement a bit off, it is
possible to calibrate them in the System ⭢ Rx Setup (second page) ⭢ Voltage Adjust menu:

The adjustment for the internal battery (usually measured by the Rx itself) and the external battery (usually as a standalone telemetry sensor) can be made independently there.