Samsung WEP850 - Manual (Page 5)

English
Charging the headset
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 charger into the jack on the headset and into a power outlet.
2 Disconnect the charger from the power outlet and the headset when
the indicator light changes to blue.