Nikon Z 8 Reference Manual page 31

WARNING (Batteries)
Discontinue use immediately should you notice any changes in the batteries, such as
discoloration or deformation. Cease charging EN‑EL15c rechargeable batteries if they do not
charge in the specified period of time.
Failure to observe these precautions could result in the batteries leaking, overheating, rupturing, or
catching fire.
When batteries are no longer needed, insulate the terminals with tape.
Overheating, rupture, or fire may result should metal objects come into contact with the terminals.
If battery liquid comes into contact with a person's skin or clothing, immediately rinse the
affected area with plenty of clean water.
Failure to observe this precaution could result in skin irritation.
31
For Your Safety