Canon EOS 7D Instruction Manual page 248

3 Checking the Battery Information
Labeling the Serial No. on the Battery
Affixing the serial No. onto all the registered Battery Pack LP-E6's with
a label makes it convenient.
Serial No.
Do not affix the label on any part other than as shown in the illustration in
step 2. Otherwise, the misplaced label might make it difficult to insert the
battery or impossible to turn on the camera.
248
1
Write the serial No. on a label.
Write the serial No. displayed on the

battery history screen on a label
about 25 mm x 15 mm / 1.0 in. x 0.6
in. in size.
2
Take out the battery and affix the
label.
Set the power switch to <2>.

Open the battery compartment cover

and remove the battery.
Affix the label as shown (side with no

electrical contacts) in the illustration.
Repeat this procedure for all of your

battery packs so you can easily see
the serial No.