VTech LS1650-B User Manual page 15

Steadily on when there are more digits before the text currently
displayed.
Steadily on when there are more digits after the text currently
displayed.
Steadily on when the battery is two-third charged.
Steadily on when the battery is one-third charged.
Flashes when low battery is detected, indicating that it needs
charging.
Animates when battery is charging.
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