You Do Need power plug adapter while traveling from Botswana 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 Botswana are D and G. This is how they look like.

Botswana

In Botswana, outlets of type D and G are in use.

Type D

Type G

Chad

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

Type C

Type D

Type E

Type F