Instruction manual
6 - 13 
6 INSPECTION AND MAINTENANCE 
(2) Q172DEX module battery replacement procedure 
When the battery has been exhausted, replace the battery with a new one in 
accordance with the procedure shown below. 
POINT 
When replacing the battery, pay attention to the following. 
(1) The Multiple CPU power supply must be on for 10 minutes or longer before 
dismounting the battery. 
(2)  Encoder data in the memory are backed up for a while by a capacitor even 
after the battery is removed. However, since data in the memory may be 
erased if the time for replacement exceeds the backup time shown the 
following guaranteed value, replace the battery quickly. 
• Backup time by capacitor : 3 minutes 
Battery
(A6BAT/MR-BAT)
MITSUBISHI
LITHIUM BATTERY
Connector for battery
connection (CON4)
Encoder cable
Side of the Q172DEX
Front
Replacing Battery
Turn on the Multiple CPU system
power supply for 10 minutes or longer.
Remove the encoder cable from
Q172DEX.
Remove the Q172DEX from the base
unit.
Turn off the Multiple CPU system
power supply.
END
Install the Q172DEX to the base unit.
Connect the encoder cable to the 
Q172DEX. 
Install a new battery into the holder in
the correct direction. Connect the
lead connector to the connector
(COM4). 
Turn on the Multiple CPU system
power supply.
Disconnect the lead connector from 
the battery connector. Remove the 
old battery from its holder of the
Q172DEX.










