Nikon Z9 Mirrorless Camera - Manual (Page 851)

851 Compatible Accessories
To begin calibration, press the calibration button for about a second.
The charge lamps and calibration lamp light red while calibration is in
progress. The display can be read as follows:
Although calibration is recommended for accurate measurement of
battery charge state, calibration need not be performed when the
calibration lamp flashes. Once begun, calibration can be interrupted as
desired.
• If the calibration button is not pressed while the calibration lamp is
flashing, normal charging will begin after about ten seconds.
• To interrupt calibration, press the calibration button again. Calibration
will end and charging will begin.
When calibration is complete, the charge lamps and calibration lamp
will turn off and charging will begin immediately.
Approximate time needed to recalibrate battery
Under
2 hours
2–4 hours 4–6 hours
Over
6 hours
Charge
lamps
2h I (off) K (on) K (on) K (on)
4h I (off) I (off) K (on) K (on)
6h I (off) I (off) I (off) K (on)
Calibration lamp K (on) K (on) K (on) K (on)