Nikon D300 User Manual (en)

Battery Info
View information on the battery currently 
inserted in the camera.
Bat. meter
The current battery level expressed as a percentage.
Pic. meter
The number of times the shutter has been released with the 
current battery since the battery was last charged. Note 
that the camera may sometimes release the shutter without 
recording a photograph, for example when measuring 
preset white balance.
This item is displayed only when the camera is powered by 
an optional MB-D10 battery pack equipped with an EN-EL4a 
or EN-EL4 battery (available separately).
• [j]: Due to repeated use and recharging, calibration is 
required to ensure that battery level can be measured 
accurately; recalibrate battery before charging.
• [—]: Calibration not required.
Charging life
A five-level display showing battery age. 0 (
k) indicates 
that battery performance is unimpaired, 4 ([
l]) that the 
battery has reached the end of its charging life and should 
be replaced. Note that batteries charged at temperatures 
under about 5 °C (41 °F) may show a temporary drop in 
charging life; the charging life display will however return 
to normal once the battery has been recharged at a 
temperature of about 20 °C (68 °F) or higher.