Korg N1 Battery and /or how to save performances

Hi, I just bought a used KORG N1. I can’t seem to save any performances. I have taken off all write protects. I modify a performance, and when I power off and back on, the performance is back to the old setting.

Is there a battery on the Korg N1 that I need to change to save these settings. Or can anyone tell my why I can not seem to save any performance changes.

I opened up the keyboard, and could not see anywhere there might be a battery. I looked on the MB and nothing there.

Any help with this would truly be appreciated.

Best Regards