About the indicator charging
You can check various statuses of the headset by the indicator.
: Turns on in blue / 
: Turns on in red / -: Turns off
Charging
You can check the charging state with the indicators (red) on the charging case and the headset.
- While charging the charging case / While charging the headset
(lights up in red)
When only the charging case is being charged, the indicator (red) on the charging case lights up. The indicator (red) on the charging case turns off after charging of the charging case is complete.
While the headset is placed in the charging case and is being charged, the indicators (red) on the headset light up. The indicators (red) turn off after charging of the headset is complete.
When charging the headset and the charging case by connecting the charging case to an AC outlet, the indicators (red) on the headset and the charging case turn on. The respective indicators (red) turn off after charging of the headset and the charging case is complete. - Abnormal temperature - - - - (repeatedly flashes twice in red)
- Abnormal charging
- - - - (repeatedly flashes slowly in red)
https://helpguide.sony.net/