What to do if there is an incorrect voltage reading in OSD?

Please check the battery total voltage and the S count of the battery in the Betaflight configurator first to see if they are correct.

1.If the total voltage of the battery is incorrect, please refer to the article below to calibrate the voltage sensor on the flight controller.

https://oscarliang.com/fix-wrong-voltage-betaflight/

2.If the S count of the battery is incorrect, and you are not using a LiPo battery (with a full charge voltage is not 4.2V)

Please adjust the battery's maximum voltage and minimum voltage on the Betaflight Battery page (according to the battery's model)

Due to the default full battery voltage of 4.2v in betaflight, when using other batteries, betaflight may incorrectly recognize the battery's status.

For example: using a single-cell full voltage 4.35V 6S LiHV battery, when fully charged, the battery voltage is 4.35*6=26.1V. At this time, the flight controller will recognize the battery as a depleted state of a 7S Lipo battery.

When using non-Lipo batteries, the abnormal display of the battery power indicator on the flight controller is also due to the same reason.