Mitsubishi Electric MR-J4 Instruction Manual page 352

11. OPTIONS AND PERIPHERAL EQUIPMENT
(4) Replacement procedure of the built-in battery
When the MR-BAT6V1SET reaches the end of its life, replace the MR-BAT6V1 battery in the MR-
BAT6V1SET.
Cover
MR-BAT6V1
While pressing the locking part, open the cover.
Locking part
Replace the battery with a new MR-BAT6V1.
Press the cover until it is fixed with the projection of the
locking part to close the cover.
Projection
11 - 57