You Do Need power plug adapter while traveling from South Sudan to Saint Barthélemy.

Here is Why You Need An Adapter

The outlet and plug type used in Saint Barthélemy are C and E and in South Sudan are C and D. This is how they look like.

South Sudan

In South Sudan, outlets of type C and D are in use.

Type C

Type D

Saint Barthélemy

In Saint Barthélemy, outlets of type C and E are in use.

Type C

Type E