X20/X20S and Ethos v1.5.0 User Manual
If the battery is changed to a different type, then the limits must be set appropriately.
RTC voltage
Shows the voltage of RTC (Real Time Clock) battery in the radio. The voltage is 3.0v for a
new battery. If the voltage is below 2.7v please replace the battery inside the radio to
ensure the clock runs properly. If the voltage drops below 2.5V, and alert will be given,
please refer to Alerts / RTC voltage.