How can these data be backed up directly in the phone itself (i.e. MicroSD, USB-OTG) without needing a PC? Is it also possible without Root?
- All SMS messages.
- Call logs.
- All contacts and phonebooks.
- Applications and data. (either all or manually selected applications)
- (lesser relevant) Battery statistics. (I have ccc.bmw71.pro (does stand for battery monitor widget, not for Bayerisches MotorWerk this time.) for that purpose. But it overwrote bmw_history.txt.)
- App Metadata (AndroidManifest.xml, installation date, store, usage statistic, etc.)
- Settings, other metadata and usage statistics if possible, but that is lesser relevant.
- Anything else. (NANDROID would require rooting.).
Data by third-party messaging applications is usually included into application data.