You can check the charging status with the lamp ( 3 ).
While the battery is charging: orange when charging is complete: green
No. It does not have.
Yes, Sony NS-WS623 does have NFC connectivity option.
No. Sony WS623 comes with non-removable battery.
Hold down the button 1 for 3 seconds.
You will hear the startup sound.
When the Walkman turns on, the lamp (2) lights up.