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

Here is Why You Need An Adapter

The outlet and plug type used in Chad are C, D, E and F 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

Chad

In Chad, outlets of type C, D, E and F are in use.

Type C

Type D

Type E

Type F