Sony CFD-G30L Operating Instructions Manual page 24

Choosing the power sources (continued)
GB
24
Setting Up
3 Inserting batteries into the remote
(CFD-G50/G50L only)
Insert two R6 (size AA) batteries (not supplied)
Replacing batteries
With normal use, the batteries should last for about
six months. When the remote no longer operates the
player, replace all the batteries with new ones.