Samsung SGH-i617 User Manual page 13

Note: You must unplug the adapter before removing the battery from the
phone during charging to avoid damage.
Low Battery Indicator
When the battery is weak and only a few minutes of
talk time remain, a warning tone sounds and the "Main
Battery very low" message repeats at regular intervals
on the display and the battery icon displays. The
backlight turns off to conserve the remaining battery
power.
When the battery level becomes too low, the phone
automatically turns off.
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