Power & Source of Big Ideas

I have a Tiny4412, its was without battery a few month. Now, I put a new battery, but the hardware clock don't work. # hwclock -s hwclock: RTC_RD_TIME: Invalid argument When I installd Android, the clock work fine. I installed Linux / UbuntuCore, the clock goes to 12-31-1969 21:00 and I can't update...
Hi all !!!!

I'm a newbie in Tiny4412. I ran Android, Linux and UbuntuCore. But I need to learn backup and restore. The supervivi made backup? I am looking about this, but unsucess !!!

I active the usb mode and connect the cable to my desktop, but don't know what to do.