Mitsubishi Electric MELSERVO-J4 MR-J4 TM Instruction Manual page 346

11. OPTIONS AND PERIPHERAL EQUIPMENT
2) Removal procedure
CAUTION
Pulling out the connector of the battery without the lock release lever pressed
may damage the CN4 connector of the servo amplifier or the connector of the
battery.
11 - 53
While pressing the lock release lever,
pull out the connector.
Press down the lock release lever, and
slide the battery toward you.