Nikon Z 7 Reference Manual page 58

Battery Level
The battery level is shown in the shooting display and control
panel while the camera is on.
Monitor
The battery level display changes as the battery level diminishes,
from L through K, J, I, and finally, H. When the
battery level falls to H, suspend shooting and charge the
battery or ready a spare battery. When the battery is exhausted,
the H icon will flash; charge the battery or insert a fully-
charged spare battery.
Number of Exposures Remaining
When the camera is on, the shooting display and control panel
show the number of photographs that can be taken at current
settings (values over 1000 are rounded down to the nearest
hundred; e.g., values between 1400 and 1499 are shown as
1.4 k).
Monitor
34 First Steps
Viewfinder
Viewfinder
Control panel
Control panel