Kawasaki robot FS030-L, controller C41F - Encoder battery voltage low

Encoder battery assembly is located behind the rear black panel on the Robot arm (where the harnesses connect to).

The reason you can only move some joints in one direction is they lie outside of their limits due to encoder battery being too low and the zeroing values now being incorrect and reporting excessive angle values.

You can see the joint angles on the main status screen, and some of the joints are likely to show incorrect joint angle values - this is a clear indication of zeroing being lost.

Replace the encoder battery assembly in the arm and re-zero the robot joints using each mechanical scribe line and you'll be golden.

FYI:

The battery you referenced in your post is the SRAM backup battery for user data held on the CPU board.