Nikon Z 9 Reference Manual page 868

Have Fully-Charged Spare Batteries Ready on Cold Days
●
Partially-charged batteries may not function on cold days. In cold weather,
charge one battery before use and keep another in a warm place, ready to be
exchanged as necessary. Once warmed, cold batteries may recover some of
their charge.
Battery Level
●
•
Turning the camera on or off repeatedly when the battery is fully
discharged will shorten battery life. Batteries that have been fully
discharged must be charged before use.
•
A marked drop in the time a fully charged battery retains its charge when
used at room temperature indicates that it requires replacement. Purchase
a new rechargeable battery.
Do Not Attempt to Charge Fully-Charged Batteries
●
Continuing to charge the battery after it is fully charged can impair battery
performance.
Recycling Used Batteries
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Recycle rechargeable batteries in accord with local regulations, being sure to
first insulate the terminals with tape.
Caring for the Camera and Battery: Cautions
868