You Do Need power plug adapter while traveling from Sierra Leone to Peru.

Here is Why You Need An Adapter

The outlet and plug type used in Peru are A, B and C and in Sierra Leone are D and G. This is how they look like.

Sierra Leone

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

Type D

Type G

Peru

In Peru, outlets of type A, B and C are in use.

Type A

Type B

Type C