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

Here is Why You Need An Adapter

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

Saint Barthélemy

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

Type C

Type E

South Sudan

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

Type C

Type D