Mitsubishi Electric MELSERVO-J4 Series Transition Handbook page 648

Part 9: Review on Replacement of Optional Peripheral Equipment
5.5.3 MR-BAT6V1SET-A battery (MR-J4W2-0303B6 only)
(1) Parts identification and dimensions
(2) Battery mounting
Connect as follows.
POINT
Use MR-BAT6V1SET-A for MR-J4W2-0303B6 servo amplifier. The MR-
BAT6V1SET- A cannot be used for MR-J4W_-B servo amplifiers other than MR-
J4W2-0303B6.
Connector for servo amplifier
MR-J4W2-0303B6
CN4
MR-BAT6V1SET-A
27.4
Case
Mass: 55 [g] (including MR-BAT6V1 battery)
9 - 47
[Unit: mm]
51