About Fujufilm
Fujifilm cameras have an internal battery built to retain the settings. If left too long without the main battery inserted, it will empty, resetting the camera.
I didn’t find any information about how long the internal battery lasts, but the last time I used the camera was five months ago.
Lessons learned:
- Use the camera more, or keep it charged;
- Backup the settings.
Source: DP Review