DS3231 RTC Module Pin out and operation confusion

[Nafees Ahmed]

Hello everyone!
Its my first time interaction here at mySensors.org and this forum has been really helpful for me.
I am working on an IOT project and I have to use RTC module DS3231 (never used it before) and I am confused about one thing!
First question: Why there are same pins on two sides? as you can see in the picture on the left side there are six pins and on the right side 4 pins. I have seen a lot of tutorials and all of them use the left side of pins but no one talks about the pins on the right side. What purpose do they serve if any?

second question: My DS3231 has the battery cell installed in it (CR2032) but whenever I remove the vcc it turns off! Should not it remain on since it has the on baord battery ?

[zboblamont]

@nafees-ahmed The 4 pins are duplicated on the board, they provide I2C comms only (eg to access current time) but no Interrupts etc..
The button cell maintains the RTC, if you disconnect Vcc the clock is kept going and it's settings are preserved, so if your board gets a power cut, everything recovers on restoration of power.

[Nafees Ahmed]

@zboblamont Thank you so much I got it now

[cncman]

You may want to check this out concerning the battery https://forum.allaboutcircuits.com/threads/real-time-clock-rtc-breakout-boards-warning.118173/