Panasonic CF-W2 Series Reference Manual page 30

Battery Power
Check the Number of Bright LEDs
(When the power is off or in standby/hibernation mode)
You can view the remaining battery capacity using the following procedure.
A Close the display and confirm that the latch is locked.
B
Disconnect the AC adaptor.
C
Slide the power switch (A) and count the number of bright LEDs (B).
The number of bright LEDs (B)
0
1
2
3
4
5
Remaining Battery Capacity
0 % - 4 %
5 % - 24 %
25 % - 49 %
50 % - 74 %
75 % - 94 %
95 % - 100 %
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