You Do Need power plug adapter while traveling from Chile to Belize.

Here is Why You Need An Adapter

The outlet and plug type used in Belize are A, B and G and in Chile are C and L. This is how they look like.

Chile

In Chile, outlets of type C and L are in use.

Type C

Type L

Belize

In Belize, outlets of type A, B and G are in use.

Type A

Type B

Type G