Yaskawa Sigma-5 User Manual: Design and Maintenance - Rotary Motors - Analog Voltage and Pulse Train Reference - Manual (Page 186)

5 Operation
5.9.3 Battery Replacement
5-72
Installing a Battery in the Host Controller
1. Turn ON the control power supply of the SERVOPACK only.
2. Remove the old battery and mount the new battery.
3. After replacing the battery, turn OFF the control power supply to clear the absolute encoder battery error
alarm (A.830).
4. Turn ON the control power supply again.
5. Check that the alarm display has been cleared and that the SERVOPACK operates normally.