AASTRA DT590 for MD Evolution User Guide EN - Manual (Page 142)

Installation
MD Evolution – Cordless DT590 142
Battery
The battery compartment with the Li-Ion battery is placed on the
rear side of the handset.
Charging the battery
The battery requires charging when the Battery icon in the display
indicates low level.
Place the phone in the charger. The charging status is shown by
the Battery icon in the display. An empty battery is fully charged
after approximately 4 hours, indicated by a filled Battery icon.
Replacing the battery
If the standby time for the phone becomes too low, the battery
should be replaced by a new one. Please contact your system
administrator or your certified Aastra Sales partner for more
information.
After replacing the battery with a new one, the Battery icon can
indicate an empty battery even though it is fully charged. Placing
the phone in the charger for a while will remove the problem.
Note: To avoid fatigue of the phone’s battery connector,
use the charger instead of repeatedly replacing an empty
battery with a new one.