I'm sorry your file is missing.
SmartOffice does not have an "auto-save" function, so if you had not saved the file onto your local device, or onto a cloud storage location (Box, Dropbox, or Google Drive), the file is gone.
Normally, a run-down battery does not cause stored files to disappear. Once he battery is charged and the application is launched, the files stored on the device should reappear.
We do not maintain a server to host SmartOffice user files.
I'm sorry for the loss of your document.