AASTRA DT4x2 for BusinessPhone User Guide EN - Manual (Page 111)

111 BusinessPhone – Cordless DT412/DT422/DT432
Installation
Battery
All batteries are rechargeable.
Charging the battery
The battery requires charging when the Battery icon in the display
is half filled or empty.
Place the Cordless in the charger. A beep indicates connection with
the charger. The charging status is shown by the Battery icon in the
display. After approximately 1 hour the Cordless is fully charged,
indicated by a filled Battery icon. If the Cordless is switched off
when placed in the charger, it will start up automatically within
2 minutes.
Note: If a call is connected when the Cordless is placed in
the charger, the call will be disconnected.
Removing the battery
The battery is fastened by a screw and two hooks. To remove the
DT412 and DT422 battery, use a small coin and turn the screw to
horizontal position. To remove the DT432 battery, use the key
which is delivered with the phone and turn the screw to horizontal
position. Remove the battery by pulling the screw. When fastening
the battery again the screw has to be in horizontal position.
Notes:
Avoid using a screwdriver as it may damage the screw.
The DT432 ATEX battery pack may not be opened in
potentially explosive areas.