RTC and Brown Out Detection

Hello! I’m trying to design my own “Developement Kit”. Because of this I’ve 2 questions:

  1. For supplying the RTC in times without external power supply, I’d like to use a battery or a capacitor. Does somebody know the energy consumption of the RTC? Is there a datasteet of this RTC available?

  2. I’m writing big datablocks to the flash and during my tests I was flashing nearly all the time and every 30 seconds I was resetting the chipworkx Module cutting of the external energy supply for a short time (5 seconds). During these test I recognised that a loss of data can happen. I think the reason for that is the hard reset during the flash process, maybe especially during the writing of the FAT. Is this possible?
    My solution for this would be a brown out detection and a soft reset, when detecting the loss of power suppy. Would this work? Are there other possibilities for protecting my flash?

Thank you for your help!