Nikon Z9 Mirrorless Camera - Manual (Page 743)

743 B The Setup Menu: Camera Setup
D Number of Shots
[ No. of shots ] shows the number of times the shutter has been released.
Note that the camera may sometimes release the shutter without recording
a photograph, for example when measuring preset manual white balance.
D Charging Batteries at Low Temperatures
Batteries in general exhibit a drop in capacity at low ambient temperatures.
Even fresh batteries charged at temperatures under about 5 °C (41 °F) may
show a temporary increase from “0” to “1” in the value shown for [
Battery
age ], but the display will return to normal once the battery has been
recharged at a temperature of about 20 °C (68 °F) or higher.