Is using Shared Preferences for storing user data reliable?

Question

Will the data still be there after the user restarts his / her phone or changes SIM / battery?

Answer 1

Yes. The data is persistent. Unless the user 'restores it to factory defaults'

Answer 2

SharedPreferences are stored in the phone's internal memory, not the SD card.
They won't be erased by a reboot/battery change either.