Samsung A3LSBH600 - Manual (Page 9)

6
This headset has a rechargeable internal battery which is non-
removable. Ensure that you fully charge the battery before
using the headset for the first time.
1 Put the travel adapter into the adapter jack and into a
power outlet.
The charging status light tunes on red.
2 Disconnect the travel adapter from the power outlet and the
headset when the charging status light changes to blue.
Charging the headset