RTC Reset if Power Button is pressed for 10 seconds
Old models of SKY have Real Time Coin battery as a back-up battery as shown below.
Ways to charge the battery vary according to the main board version.
For V1.1: Charged through CPU, and RTC is reset if the power button is pressed for 10 sec.
For V1.2: Charged through the main battery and follows the main battery level.
Fully charged back-up battery can keep the date information and GPS configurations for 5 to 10 minutes without the main battery.
