Zte TELSTRA SMART TOUCH User Manual page 14

Insert the charger lead carefully:
Notes:
 If the battery is low, there will be a pop-up message on the screen and
the status indicator light will be red.
 When you charge your phone, the indicator light will change according to
the battery level:
Status Indicator
Red
Orange
Green
14
Battery level
Less than 10% charge
More then 10%, but less than 90% charge
More than 90% charge