Vivitar Vivicam 4000 User Manual page 22

Use only the specified AC power adapter. Damage caused by the use of
an incorrect adapter is not covered under the warranty.
The battery may feel warm after it has been charged or immediately after
being used. This is normal and not a malfunction.
When using the camera in cold conditions, keep the camera and battery
warm by storing it in a warm place such as an interior pocket between
shots.
If you open the battery/memory card cover without removing the battery,
the battery power will not be disconnected. If you remove the battery for
more than two hours the date and time must be reset.
Never attempt to use an AC adapter/charger with the Vivicam 4000 if you
are using a Duracell CP1 battery.
22-E