PLC CPU's contain the battery model D2-BAT-1 which is critical for memory retention of the PLC's stored values. If your battery is low or depleted it is critical to replace as any power loss or shutdown of the system can result in a loss of these stored values.
Ensure your PLC CPU is on, and powered by the hard-line wired connection before removing the battery.
Locate, and open the PLC battery port.
Remove the low or depleted battery
Insert the new battery in the same orientation, with the plus + side toward the tray.
Gently close the battery tray, if inserted backwards it can break the plastic battery tray.
Ensure the PLC Run switch is toggled to the ON position.
The PLC HMI alerted you that a PLC battery was low or depleted
A Cleereman Technician notified you that a PLC battery needed to be replaced
Verify battery is inserted in the correct orientation
Verify battery port is not broken or damaged
Replace PLC CPU