You Do Need power plug adapter while traveling from El Salvador 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 El Salvador are A and B. This is how they look like.

El Salvador

In El Salvador, outlets of type A and B are in use.

Type A

Type B

Chad

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

Type C

Type D

Type E

Type F