How to run the inbuild RTC in rockpi 4c+

i bought several rockpi 4c+ . Also, i need RTC. But this documentation from radxa says, 4c+ does not have any RTC battery connector but it has an inbuild RTC. But then how that RTC will run if I can not connect any battery?

It runs as long as there is board power, that’s it. It you need an RTC that runs without powering the board, use an external module, there are plenty of offers for RPi 4 that will also work on 4C+.

Thanks for the reply. But then what is the point of having an rtc on board if it can not keep track of the time when the board is not running?

My educated guess: The RTC is part of one IC that is needed anyway, originally it was designed WITH a connector (as all other Rock Pi 4 have), someone decide it should be without for “compatibility with whatever” and it was easier to remove the connector then to replace the IC.