Nikon Z 8 Reference Manual page 927

To ensure that you get the most from rechargeable Nikon EN‑EL15c batteries:
Keep the battery contacts clean. Soiled contacts can reduce battery performance.
Use batteries immediately after charging. Batteries will lose their charge if left unused.
1 EN‑EL15b and EN‑EL15a batteries can be used in place of the EN‑EL15c. Note, however, that fewer
pictures can be taken on a single charge than with the EN‑EL15c.
2 Measured at 23 °C/73.4 °F (±2 °C/3.6 °F) with a SONY CEB‑G128 memory card.
3 Camera and Imaging Products Association (CIPA) standard. One photograph taken at default
settings once every 30 s. Measured with a NIKKOR Z 24–70mm f/4 S lens.
4 In-house measurements. Image quality set to JPEG normal, image size to "Large", shutter speed to
¹⁄₂₅₀ s, shutter-release button pressed halfway for 3 s and focus cycled from infinity to minimum
range three times before a burst of six shots, after which the viewfinder is turned on for 5 s and
then turned off and the standby timer allowed to expire. This process is then repeated. Measured
with a NIKKOR Z 70–200mm f/2.8 VR S lens. [Viewfinder only] was selected for monitor mode.
5 Actual battery endurance as measured under conditions specified by CIPA. Measured with a
NIKKOR Z 24–70mm f/4 S lens. Measurement performed at default settings.
Each shot can be up to 125 minutes in length.
If camera temperature rises, recording may end before maximum length or size is reached.
927
Battery Endurance