Canon EOS R Advanced User's Manual page 390

Checking the Battery Information
Checking the Remaining Capacity of a Registered Battery
You can check the remaining capacity of batteries not currently in use,
as well as their last date of use.
(1)
(2)
Deleting the Registered Battery Information
1
Select [Delete info.].
Follow step 2 on page 387 to select [Delete info.].
z
2
Select the battery information to delete.
[ X ] will appear.
g
3
Press the < L > button.
Select [OK] on the confirmation dialog.
z
390
Look for the serial number.
(3)
Refer to the battery's serial number
z
label and look for the battery's serial
number (1) on the battery history
screen.
You can check the respective battery's
g
approximate remaining capacity (2)
and the date when it was last used (3).