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

Here is Why You Need An Adapter

The outlet and plug type used in Falkland Islands is G 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

Falkland Islands

In Falkland Islands, outlets of type G are in use.

Type G