RTC module only on backup battery no 5v from arduino?


I have a tinyRTC module that i want to use in a clock project.

My question is do i have to connect it to the arduino 5v or can i just run it from the backyp battery. 3.3v to 4.1v

My idea is to have a li ion battery powering the rtc and the arduino. However if i connect the rtc to 5v arduino it wil use the battery to charge the battery.....

So, is it possible to just connect the poles of the backup battery holder to the main battery?

Most RTCs will go into backup mode when there is no VCC (the Arduino 5V) present and you wont be able to access it.

You can check if this is true for your particular RTC by reading its datasheet.