Samsung SGH-t309 - Manual (Page 13)

Section 1: Getting Started 9
Activating Your Phone
Section 1
3. When charging is finished, unplug the adapter from the
power outlet and disconnect it from the phone by
pressing the buttons on both sides of the connector (1)
and pulling the connector out (2).
Note: You must unplug the adapter before you remove the battery from the
phone during charging; otherwise, the phone could be damaged.
Low Battery Indicator
When the battery is weak and only a few minutes of talk
time remain, a warning tone sounds and the “Warning
Low Battery” message repeats at regular intervals on the
display. When this happens, your phone turns off the
backlight to conserve the remaining battery power.
When the battery level becomes too low, the phone
automatically turns off.