I am trying to get the rtc i2c ds1307 module working under Raspbian Jessie.
I followed these guide to let the raspberry recognize the module and set it up.
Fortunately everything works great. I can access the module, read and write the time with
But as soon as I disconnect my raspberry from power supply my rtc module looses time (reset to 2000-01-01 00:00:00). The 3V Battery is fully charged.
What could be the reason for that behavior?
If I just reboot the pi without disconnecting it from power the rtc keeps the time correctly.