1, it may be that the battery inside is old, or other reasons for battery damage.
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2. It may be that the charging indicator light of the Bluetooth headset is broken.
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3. The earphone charging port or charging cable is in poor contact with the power port.
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4, the charging plug or power cord is not original, resulting in excessive input voltage, the battery has a protection board, will automatically turn off the external power supply.
This is normal, the red light is on when charging, and it turns green when the electricity is full, this is that the electricity is not full, if it is full, it will turn green.
No, it's not full of red.